Trevi shower stopped working
treen...@googlemail.com
was a slight modification to the outside of the heating loop through
the DHW cylinder but the DHW supply plumbing was untouched and the
flow rate through all the hot taps is unchanged.
My Trevi Boost shower has stopped working though, after being fine for
3 years. I've flushed and cleaned it out but it's still running stone
cold at all settings.
I've now noticed that the pressure of the cold supply is reversing the
lower pressure hot supply and sending cold water back along the hot
pipe.
I see from the installation instructions that there should be non-
return valves on each supply pipe. There isn't currently.
Of the 4 recommended check valves in the Trevi installation guide, non
were available via Web searches. The only references to them were in
on-line versions of the Trevi Boost installation guide.
Thinking about alternative valve sources, I couldn't help wondering
how, with both incoming water pressures being quite consistent, why
wouldn't the same pressure conditions that forced cold water down the
hot pipe when there is no check valve, not just stop the hot water
from entering the mixer when there is a check valve?
Dick Treen
RubberBiker
in the cold side and didn't fit one hot side (as it would restrict
flow and cause an extra pressure drop).
My trevi is probably about the same age as yours, and occasionally it
will remain running stone cold too - but so far I've always been able
to remedy it by twisting the temperature knob from min to max a few
times (I suspect it's a bit of limescale forming).
The fact that you're getting cold flow back through the hot supply to
the trevi doesn't sound good. AIUI they have a venturi inside that
*should* ensure the high pressure cold flow creates a vacuum to
increase the hot flow (see http://en.wikipedia.org/wiki/Venturi_effect)
- perhaps when you cleaned it out something was damaged or incorrectly
fitted?
treen...@googlemail.com
> I've an open vented system with a trevi boost. I fitted a check valve
> in the cold side and didn't fit one hot side (as it would restrict
> flow and cause an extra pressure drop).
This is what put me off using a check valve on the hot side during the
original installation.
I've since seen that there are "swing" valves available, with less
resistance but they have very different shapes and fittings than the
usual plumbing, though I'm pretty sure they could be adapted.
I've now received another message from Trevi. I'm told that because I
have 22mm pipework from the rising main to the cold port of the shower
unit, it's a fluke that the shower ever worked at all. The message
describes it as "imperative" that the cold pipework size be 15mm.
the cold inlet port on the shower unit is 22mm though and it's
recommended that the check valve on the cold side be 22mm.
As most of the cold water pipework in the house is 22mm from the
rising main onward, how much of the length of the pipework branch
leading to the bath tap and shower would need to be reduced to 15mm?
Would a metre or so have the required effect?
> My trevi is probably about the same age as yours, and occasionally it
> will remain running stone cold too - but so far I've always been able
> to remedy it by twisting the temperature knob from min to max a few
> times (I suspect it's a bit of limescale forming).
My Temperature knob has had plenty of twisting recently. I also live
in a low lime area.
There was a lot of whiteish scum on the filter gauzes before I
toothbrushed them.
> The fact that you're getting cold flow back through the hot supply to
> the trevi doesn't sound good.
You're right, it doesn't sound good and I was never aware of it
happening before. Although according to Trevi, this is a common
feature of "Unbalanced" systems and why they advise the fitting of the
check valves.
> AIUI they have a venturi inside that
> *should* ensure the high pressure cold flow creates a vacuum to
> increase the hot flow (seehttp://en.wikipedia.org/wiki/Venturi_effect)
Yes, that's how I understand it should be working and how perhaps it
must have been working on it's good days.
> - perhaps when you cleaned it out something was damaged or incorrectly
> fitted?
This is possible, though I only brushed the filter gauzes on the mixer
cartridge and it's now not-working any differently since the clean up
than it was not working immediately before.
Dick Treen
Roger
from "treen...@googlemail.com" <treen...@googlemail.com> contains
these words:
Are you sure about the incoming pressure being consistent?
ISTR that the Trevi Boost has a requirement for a 3 bar limit otherwise
the conditions you describe are likely to occur. Unfortunately I can't
remember too much about the shower I installed for my sister a few years
ago and, at 250 miles distant, it is a bit too far to go and look at the
set-up.
--
Roger Chapman
treen...@googlemail.com
> The message <e94d5a6d-8d5f-4630-885e-35f9793cd...@t3g2000yqa.googlegroups.com>
> from "treenoa...@googlemail.com" <treenoa...@googlemail.com> contains
> these words:
>
>
>
> > I recently had a new gas boiler fitted on my open vented system. there
> > was a slight modification to the outside of the heating loop through
> > the DHW cylinder but the DHW supply plumbing was untouched and the
> > flow rate through all the hot taps is unchanged.
> > My Trevi Boost shower has stopped working though, after being fine for
> > 3 years. I've flushed and cleaned it out but it's still running stone
> > cold at all settings.
> > I've now noticed that the pressure of the cold supply is reversing the
> > lower pressure hot supply and sending cold water back along the hot
> > pipe.
> > I see from the installation instructions that there should be non-
> > return valves on each supply pipe. There isn't currently.
> > Of the 4 recommended check valves in the Trevi installation guide, non
> > were available via Web searches. The only references to them were in
> > on-line versions of the Trevi Boost installation guide.
> > Thinking about alternative valve sources, I couldn't help wondering
> > how, with both incoming water pressures being quite consistent, why
> > wouldn't the same pressure conditions that forced cold water down the
> > hot pipe when there is no check valve, not just stop the hot water
> > from entering the mixer when there is a check valve?
> Are you sure about the incoming pressure being consistent?
Not exactly but they seem not to vary much visually.
I haven't measured them by the recommended methods since just before I
fitted the shower.
I also didn't keep my notes on those original measurements, although I
probably wouldn't have gone ahead if these flows and pressures were
outside the spec.
Things may well have changed over time.
>
> ISTR that the Trevi Boost has a requirement for a 3 bar limit otherwise
> the conditions you describe are likely to occur. Unfortunately I can't
> remember too much about the shower I installed for my sister a few years
> ago and, at 250 miles distant, it is a bit too far to go and look at the
> set-up.
Being an amateur, I sometimes have a tendency to do a lot more
deconstruction when problems arise than is necessary, or than is good
for the health of the
job in hand. I'm trying to get as much advice as possible before
pulling the unit apart again, though it looks like I'll have to take
the cartridges out to measure the pressure and flow.
Dick Treen
Roger
<7c72823b-3945-412d...@i38g2000yqd.googlegroups.com>
> Being an amateur, I sometimes have a tendency to do a lot more
> deconstruction when problems arise than is necessary, or than is good
> for the health of the
> job in hand. I'm trying to get as much advice as possible before
> pulling the unit apart again, though it looks like I'll have to take
> the cartridges out to measure the pressure and flow.
You can measure mains pressure at any cold water tap fed from the mains.
Just adjust the result for the difference in height. Outside taps
threaded for hosepipe connectors are said to be ideal for attaching a
pressure gauge.
Incidentally I can't see why using 22mm pipe instead of 15mm in the cold
supply would be detrimental. It just means that there would be a lower
pressure drop in the pipe during operation. I would have thought it
might be a problem if you used 15mm when 22mm was specified, too great a
pressure drop might restrict the flow too much but given sufficient
capacity surely it is the valve that controls the flow, not the supply
pipe diameter. Perhaps Trevi could explain their reasoning.
--
Roger Chapman
treen...@googlemail.com
I'm writing to Trevi (Ideal Standard) on quite a regular basis lately
and the things I'm learning here are a big help in that respect.
> > Being an amateur, I sometimes have a tendency to do a lot more
> > deconstruction when problems arise than is necessary, or than is good
> > for the health of the
> > job in hand. I'm trying to get as much advice as possible before
> > pulling the unit apart again, though it looks like I'll have to take
> > the cartridges out to measure the pressure and flow.
>
> You can measure mains pressure at any cold water tap fed from the mains.
> Just adjust the result for the difference in height. Outside taps
> threaded for hosepipe connectors are said to be ideal for attaching a
> pressure gauge.
Thanks, that's very helpful.
I do have a threaded outside tap and since the bathroom and kitchen
upgrades, the current indoor taps don't lend themselves as well to the
attachment of hoses as the old variety did. Is there an easy method
for calculating the height difference?
Then again, I've just found a "DUALUX FLUSHING NIPPLE BUILT-IN" which
came with the original shower kit. It seems like it's meant to
temporarily replace the cold (or hot) inlet cartridges for flushing
purposes. Perhaps if this could be adapted to measuring the pressure
at the shower unit itself, the results would be more directly
applicable.
> Incidentally I can't see why using 22mm pipe instead of 15mm in the cold
> supply would be detrimental. It just means that there would be a lower
> pressure drop in the pipe during operation. I would have thought it
> might be a problem if you used 15mm when 22mm was specified, too great a
> pressure drop might restrict the flow too much but given sufficient
> capacity surely it is the valve that controls the flow, not the supply
> pipe diameter. Perhaps Trevi could explain their reasoning.
Yes that's what I've been struggling to understand, especially as the
shower has previously been working fine for years.
But, so as not to rock the boat, I've only so far asked "what is the
minimum length run of 15mm pipwork that needs to be introduced into
the existing 22mm supply in order to comply with the Installation
spec". I've yet to receive a reply on that one.
I've been able to vary the pressure and flow of the cold supply over a
wide range by partially closing the rising main stop-cock. It seems to
me that 22mm pipework offers access to a much wider range of user
applied variations than the 15mm pipes would, including those that
would be available if 15mm pipework was installed. There may be other
limiting factors I'm not aware of.
Dick Treen
RubberBiker
me. IIRC the installation instructions made much of the fact that hot
supply must be 22mm right the way through - absolutely true and
reasonable as it greatly increases low pressure flow. But this
statement about the diameter of the cold pipe sounds like some utter
numpty at trevi (mis)reading a leaflet and thinking he's an expert.
For pressure measurement, screwfix do a cheap gauge that will fit
washing machine taps, and/or outdoor tap fittings:
treen...@googlemail.com
Yes indeeed!
> The "there must be 15mm pipework for cold" argument sounds like BS to
> me. IIRC the installation instructions made much of the fact that hot
> supply must be 22mm right the way through - absolutely true and
> reasonable as it greatly increases low pressure flow. But this
> statement about the diameter of the cold pipe sounds like some utter
> numpty at trevi (mis)reading a leaflet and thinking he's an expert.
As I'm still in ongoing communication with the helpful people at the
Ideal Standard, Trevi section on this problem I'll need to avoid utter
numpty conclusions for now.
I did receive an answer a little while ago to my question about the
minimum 15mm pipe run required and was told:
---------------------------------------
"Unfortunately we do not specify a minimum length for the 15mm run as
we specify the entire run must be 15mm with no exceptions. We cannot
support or guarantee normal operation of the valve outside of these
installation requirements."
----------------------------------------
So if the rising main emerged in the bathroom itself, from there 2
Metres of 15mm pipe would conform to the installation spec.
But as the rising main is 20 Metres away from the shower, the 15mm
pipe run has to be 20Metres long to conform?
The message also added:
------------------------------------------
"If the cold header tank were at the maximum 3.0 metres head, the
stored hot water temperature were up around the maximum 75 degs
celsius, and the cold mains pressure at the minimum 1.5 bar, this will
give the hot water the best chance of getting through if the cold
supply pipework was too large."
------------------------------------------
It'll take me a bit longer to pick the bones out of the second part of
the message.
.
> For pressure measurement, screwfix do a cheap gauge that will fit
> washing machine taps, and/or outdoor tap fittings:
>
> http://www.screwfix.com/prods/82412/Hand-Tools/Plumbing-Tools/Pressur...
Thanks for the link. Originally I used a tyre pressure gauge from
Halfords but the situation is perhaps getting a little too demanding
for such bodges at this stage,
Dick Treen
Roger
<6e500309-b8f6-46fc...@t11g2000yqg.googlegroups.com>
> I do have a threaded outside tap and since the bathroom and kitchen
> upgrades, the current indoor taps don't lend themselves as well to the
> attachment of hoses as the old variety did. Is there an easy method
> for calculating the height difference?
A tape measure held vertically. :-)
I presume you mean converting the height into bar. If so 1 bar is close
to 10 metres water head.
--
Roger Chapman
Doctor Drivel
news:be8a7013-a2b8-4071...@r4g2000yqa.googlegroups.com...
> I've now received another message from Trevi. I'm told that because I
> have 22mm pipework from the rising main to the cold port of the shower
> unit, it's a fluke that the shower ever worked at all.
Find out what the maximum cold "flow" and pressure is. If flow way too high
then insert a flow regulator in the cold line. Available from BES.
http://www.bes.co.uk If pressure is way too high fit a pressure reducer
too.
treen...@googlemail.com
> from "treenoa...@googlemail.com" <treenoa...@googlemail.com> contains
> these words:
>
> > I do have a threaded outside tap and since the bathroom and kitchen
> > upgrades, the current indoor taps don't lend themselves as well to the
> > attachment of hoses as the old variety did. Is there an easy method
> > for calculating the height difference?
>
> A tape measure held vertically. :-)
I can do that. :-)
> I presume you mean converting the height into bar. If so 1 bar is close
> to 10 metres water head.
Yes.
That's something I can do too. Thanks a lot.
Dick Treen
David Hansen
"treen...@googlemail.com" <treen...@googlemail.com> wrote this:-
>Thanks for the link. Originally I used a tyre pressure gauge from
>Halfords but the situation is perhaps getting a little too demanding
>for such bodges at this stage,
If the cold pressure is outside the specification then a suitable
pressure regulating valve in the cold would be more useful than a
length of 15mm pipe. However as you have already tried turning down
the main stop tap this may not be the problem.
Have you checked that water does come out of the hot pipe at the
shower and it has not been blocked by some debris? Is there debris
in the hot filter in the shower? Something might have been dislodged
or drawn in while the work was being done.
--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54
treen...@googlemail.com
wrote:
> On Tue, 24 Feb 2009 07:08:55 -0800 (PST) someone who may be
>
> >Thanks for the link. Originally I used a tyre pressure gauge from
> >Halfords but the situation is perhaps getting a little too demanding
> >for such bodges at this stage,
>
> If the cold pressure is outside the specification then a suitable
> pressure regulating valve in the cold would be more useful than a
> length of 15mm pipe.
It does seem that way to me, though any tips from experience are
useful and appreciated.
I'm working on the basis that there can't be much stopping the shower
working as there has been so little that's changed since it was.
There are 3 main components in the shower body and I've just replaced
2 of them.
The remaining valve is 145quid+ to replace, so I'm trying to ensure
that all the less expensive changes are made first. I wouldn't want to
spend big bucks only to find it still hasn't done the trick.
> However as you have already tried turning down
> the main stop tap this may not be the problem.
I'm not certain about that but it does seem unlikely to be a problem
with the cold supply.
Unless I can locate the problem and remove it, I'll be working my way
through the installation spec again and scrupulously ensuring that the
details are followed.
I' don't think I'll be prepared to entirely remove the 22mm cold
supply and replace it with 15mm though. So a pressure regulating valve
may well be next on the list
> Have you checked that water does come out of the hot pipe at the
> shower and it has not been blocked by some debris?
The flow of hot water doesn't appear to be significantly reduced but
it may be affected enough to cause the shower to fail.
I'm wondering if a mains pressure hose connected to one hot tap at a
time might blow any obstructions back into the header tank where they
could be strained out.
I'm guessing that any debris wouldn't make it back further than the
DHW cylinder though, from where it could eventually be carried back to
the problem area.
> Is there debris
> in the hot filter in the shower? Something might have been dislodged
> or drawn in while the work was being done.
I've spent quite some time cleaning the filters but the way it's going
I'll soon be spending some more.
Dick Treen
treen...@googlemail.com
> <treenoa...@googlemail.com> wrote in message
>
> news:be8a7013-a2b8-4071...@r4g2000yqa.googlegroups.com...
[---]
> > I've now received another message from Trevi. I'm told that because I
> > have 22mm pipework from the rising main to the cold port of the shower
> > unit, it's a fluke that the shower ever worked at all.
>
> Find out what the maximum cold "flow" and pressure is. If flow way too high
> too.
Thanks, I'll be happy to fit either or both of these.
The installation guide describes the cold supply in terms of "flow
pressure", the acceptable range being 1.5 -to- 3 bar.
One of several things confusing me at present are the charts which
show that at 1.5 -to- 2 bar, the hot water temp requirement is 65C
min, when at zero head.
Whereas, at 2 -to- 3 bar the hot water temp requirement is 60C min,
when at zero head.
My practical take on the situation has been that an excess of cold
supply was overwhelming the effect of the hot supply which makes the
above info a bit counter-intuitive. I've looked at the previous
discussions on the flow/pressure equations and it made my head hurt.
Can anyone please tell me: if the cold supply pipes should be 15mm,
but instead are 22mm, which in terms of flow or pressure is the one
most likely to be in excess of spec?
Dick Treen
Doctor Drivel
<treen...@googlemail.com> wrote in message
news:cb98abb2-7ec3-41a1...@41g2000yqf.googlegroups.com...
Find out what the pressure is first.
treen...@googlemail.com
> <treenoa...@googlemail.com> wrote in message
>
> news:cb98abb2-7ec3-41a1...@41g2000yqf.googlegroups.com...
>
>
>
> > On 24 Feb, 15:33, "Doctor Drivel" <killef...@invalid.invalid> wrote:
> >> <treenoa...@googlemail.com> wrote in message
>
> >>news:be8a7013-a2b8-4071...@r4g2000yqa.googlegroups.com...
> > [---]
> >> > I've now received another message from Trevi. I'm told that because I
> >> > have 22mm pipework from the rising main to the cold port of the shower
> >> > unit, it's a fluke that the shower ever worked at all.
>
> >> Find out what the maximum cold "flow" and pressure is. If flow way too
> >> high
> >> then insert a flow regulator in the cold line. Available from
> >> reducer
> >> too.
>
> > Thanks, I'll be happy to fit either or both of these.
> > The installation guide describes the cold supply in terms of "flow
> > pressure", the acceptable range being 1.5 -to- 3 bar.
>
> > One of several things confusing me at present are the charts which
> > show that at 1.5 -to- 2 bar, the hot water temp requirement is 65C
> > min, when at zero head.
> > Whereas, at 2 -to- 3 bar the hot water temp requirement is 60C min,
> > when at zero head.
>
> > My practical take on the situation has been that an excess of cold
> > supply was overwhelming the effect of the hot supply which makes the
> > above info a bit counter-intuitive. I've looked at the previous
> > discussions on the flow/pressure equations and it made my head hurt.
>
> > Can anyone please tell me: if the cold supply pipes should be 15mm,
> > but instead are 22mm, which in terms of flow or pressure is the one
> > most likely to be in excess of spec?
>
> Find out what the pressure is first.
Hi again, it's 2.5 bar at the unit itself, well above the min 1.5 bar.
Also, the hot water at 65C is flowing at 17LPM through the unit, which
is optimum according to the book.
I put a swing type check valve into the hot supply pipework to
minimise resistance and now the shower works marginally well
(lowest combined flow rate through the mixer gets a reasonably hot
shower).
On the 22mm cold supply side I notice that only the flow rate changes
if I adjust the stop-cock, the pressure remains the same.
Other than swapping the 22mm pipes for 15mm, the only other option
seems to be to but in flow/pressure regulation but as I can change
the flow at the stop-cock and the current 2.5 bar pressure is under
the 3 bar max, I'm not sure if these moves would produce much effect.
Regards,
Dick Treen
Roger
> > Find out what the pressure is first.
> Hi again, it's 2.5 bar at the unit itself, well above the min 1.5 bar.
> Also, the hot water at 65C is flowing at 17LPM through the unit, which
> is optimum according to the book.
> I put a swing type check valve into the hot supply pipework to
> minimise resistance and now the shower works marginally well
> (lowest combined flow rate through the mixer gets a reasonably hot
> shower).
> On the 22mm cold supply side I notice that only the flow rate changes
> if I adjust the stop-cock, the pressure remains the same.
> Other than swapping the 22mm pipes for 15mm, the only other option
> seems to be to but in flow/pressure regulation but as I can change
> the flow at the stop-cock and the current 2.5 bar pressure is under
> the 3 bar max, I'm not sure if these moves would produce much effect.
You addressed your question to Dribble but he is mute so far. Hopefully
he has finally been sectioned under the mental health act but if not no
doubt he will be along eventually to accuse all and sundry (and me in
particular) of being plantpots and to confuse the issue with his lack of
understanding of basic physics.
If you restrict the stop cock enough you will get a measurable reduction
in pressure along with your reduced flow rate. I don't know enough about
fluid dynamics to know how well that will mimic the pressure/flow rate
pattern of a length of 15mm pipe but it is likely that there will be no
greater variation between a stop tap restriction and a short length of
15mm pipe than there is between a short length of pipe and a long length
of pipe which puts Trevi's need for a 15mm supply pipe into question.
My memory being what it is these days I can't recall the detail of what
went before but have you considered raising the temperature of the hot
water to change the balance between hot and cold?
--
Roger Chapman
treen...@googlemail.com
> The message <ba6fd351-89ac-409c-8640-cfe58bc93...@33g2000yqm.googlegroups.com>
> from "treenoa...@googlemail.com" <treenoa...@googlemail.com> contains
I do think this15mm requirement is a bit suspect, maybe just thrown in
to allow the Ideal Standard customer services to wash their hands of
the problem.
treen...@googlemail.com
> My memory being what it is these days I can't recall the detail of what
> went before but have you considered raising the temperature of the hot
> water to change the balance between hot and cold?
>
> --
> Roger Chapman
Thanks very much Roger.
The new boiler has a max DHW temp of 65C, which it's at now,
I could get the electric immersion heater set up on a timer to provide
70C at certain times of day.
This seems like one of the few remaining solutions.
Regards,
Dick Treen
Roger
<5a6669b9-9b71-4497...@v39g2000yqm.googlegroups.com>
> The new boiler has a max DHW temp of 65C, which it's at now,
> I could get the electric immersion heater set up on a timer to provide
> 70C at certain times of day.
> This seems like one of the few remaining solutions.
The only other thing I can think of is for you to increase the hot water
pressure by raising the cold water tank but that may not be practical
and I have no idea how much extra head would be required to make a
significant difference.
--
Roger Chapman
treen...@googlemail.com
>[...]
> The only other thing I can think of is for you to increase the hot water
> pressure by raising the cold water tank but that may not be practical
> and I have no idea how much extra head would be required to make a
> significant difference.
>
> --
> Roger Chapman
Measuring from the surface of the water in the tank to the mixer unit
it's just under 2M.
The shower is said to work with negative head, so around 2M head (as
defined in the Installation guide) doesn't seem too disadvantageous.
It's a shallow roofspace too, so not a lot of leeway there.
I could maybe squeeze some extra head by bending the arm of the
ballcock, but I already did that once, so not a tremendous amount left
there.
I'd rather attempt remedies which don't involve using electrical
boosting but I seem to be running out of options.
Regards,
Dick Treen
Tim Downie
What happens when you remove the shower head?
If it's a venturi system that's worked in the past the only reason I can
think of for cold water now going back up the hot supply is some sort of
partial obstruction raising the resistance to flow after the venturi. (or a
fault with the venturi itself).
Tim
treen...@googlemail.com
wrote:
> treenoa...@googlemail.com wrote:
> > On 23 Mar, 17:40, Roger <ro...@nospam.zetnet.co.uk> wrote:
> >> [...]
> >> The only other thing I can think of is for you to increase the hot
> >> water pressure by raising the cold water tank but that may not be
> >> practical and I have no idea how much extra head would be required
> >> to make a significant difference.
>
> >> --
> >> Roger Chapman
>
> > Measuring from the surface of the water in the tank to the mixer unit
> > it's just under 2M.
> > The shower is said to work with negative head, so around 2M head (as
> > defined in the Installation guide) doesn't seem too disadvantageous.
> > It's a shallow roofspace too, so not a lot of leeway there.
> > I could maybe squeeze some extra head by bending the arm of the
> > ballcock, but I already did that once, so not a tremendous amount left
> > there.
> > I'd rather attempt remedies which don't involve using electrical
> > boosting but I seem to be running out of options.
[...]
> What happens when you remove the shower head?
No noticable change in flow rate or temp with the head and hose off.
> If it's a venturi system that's worked in the past the only reason I can
> think of for cold water now going back up the hot supply is some sort of
> partial obstruction raising the resistance to flow after the venturi.
The pipework and brass body of the unit have had a good flushing out
recently, repeated several times.
(or a fault with the venturi itself).
I didn't want to replace the "Trevi Boost" cartridge unless I was
forced to because of the cost, so I stood it in a caustic soda
solution for 20 minutes, in the hope that the internals weren't made
of aluminium. No sign of any damage as a result but not a lot of
improvement in the performance either.
>
> Tim
Regards,
Dick Treen
Tim Downie
<treen...@googlemail.com> wrote in message
news:d4345d0e-db91-43a5...@h5g2000yqh.googlegroups.com...
> I'd rather attempt remedies which don't involve using electrical
> boosting but I seem to be running out of options.
I know you said that the domestic hot water side of things wasn't touched
but is there any chance that an air lock was introduced into the system
somehow?
You say cold water is flowing back up the h ot supply. Does the pipe run
cold all the way back to the HW tank or is it just a question of it running
a foot or two back from the shower valve?
If there was an air lock and your hot supply runs up to the loft say and
then down to the shower, it may be that the venturi isn't capable of
producing enough suction to lift the water up to the loft.
Can you turn on *just* the hot water and get tank temperature HW (at low
flow & pressure) from your shower?
I realise you've probably thought of all this but air locks can do funny
things.
Tim
>
> Regards,
> Dick Treen
treen...@googlemail.com
wrote:
> <treenoa...@googlemail.com> wrote in message
>
> news:d4345d0e-db91-43a5...@h5g2000yqh.googlegroups.com...
>
> > I'd rather attempt remedies which don't involve using electrical
> > boosting but I seem to be running out of options.
[...]
> I know you said that the domestic hot water side of things wasn't touched
> but is there any chance that an air lock was introduced into the system
> somehow?
I think perhaps there was but not in this context. Since you mention
it though, I still can't figure out why
some pipework changes were made to the heating loop, so I'll ask here.
Originally, on the pipework to and from the DHW cylinder coil, the
connection to the top port had a 22mm expansion pipe branch going up
to vent in the tank area.
The bottom connection port had a 15mm supply pipe branch from the
header tank.
For some reason the plumber found it necessary to cut and cap off the
15mm supply pipe a couple of feet above the lower cylinder coil port,
then join the supply from the header tank into the 22mm expansion pipe
a little higher up in the airing cupboard.
All well and good not understanding the principle involved if things
were ok but there seems to be a lot of air and gurgling in the loop
now despite many bleedings.
> You say cold water is flowing back up the h ot supply. Does the pipe run
> cold all the way back to the HW tank or is it just a question of it running
> a foot or two back from the shower valve?
Before the check valve went in, it was a couple of feet at a guess.
Now that particular problem is sorted.
> If there was an air lock and your hot supply runs up to the loft say and
> then down to the shower, it may be that the venturi isn't capable of
> producing enough suction to lift the water up to the loft.
I don't think it's as complicated as that and the hot flow seems quite
consistent.
> Can you turn on *just* the hot water and get tank temperature HW (at low
> flow & pressure) from your shower?
I could when I had the unit stripped down and it was flowing ok. In
it's fully functioning state the hot and cold turn on simultaneously.
> I realise you've probably thought of all this but air locks can do funny
> things.
Yes, hours of damp amusement and numerous opportunities to buy
equipment that will probably never be used again. ;-)
Regards,
Dick Treen
Tim Downie
> On 24 Mar, 17:38, "Tim Downie" <timdownie2...@obvious.yahoo.co.uk>
> wrote:
>
>> I know you said that the domestic hot water side of things wasn't
>> touched but is there any chance that an air lock was introduced into
>> the system somehow?
>
> I think perhaps there was but not in this context. Since you mention
> it though, I still can't figure out why
> some pipework changes were made to the heating loop, so I'll ask here.
>
> Originally, on the pipework to and from the DHW cylinder coil, the
> connection to the top port had a 22mm expansion pipe branch going up
> to vent in the tank area.
> The bottom connection port had a 15mm supply pipe branch from the
> header tank.
That sounds small and will throttle HW output. It seems odd that your
shower should have 22mm pipework when the cyclinder output is being
strangled by such a relatively small input.
> For some reason the plumber found it necessary to cut and cap off the
> 15mm supply pipe a couple of feet above the lower cylinder coil port,
Now you've got me confused. The cold water feed shouldn't have anything to
do with the coil which is for indirect heating of the cylinder contents and
is fed from the CH boiler.
> then join the supply from the header tank into the 22mm expansion pipe
> a little higher up in the airing cupboard.
So there's no cold supply to the base of the tank??
> All well and good not understanding the principle involved if things
> were ok but there seems to be a lot of air and gurgling in the loop
> now despite many bleedings.
Have a look at http://www.aquabrand.com/img/gravity_large.jpg and see if
your tank connections correspond.
There really ought to be a 22mm cold feed to the base of the tank.
It sounds like you plumber has done something odd that is resulting in the
shower sucking water from the cold feed rather than the HW tank. The
gurgling noises would rather support this.
I think you need someone to cast an eye over your system (or post some
photos of your tank connections and loft tank arrangements).
Tim
Tim Downie
> I think perhaps there was but not in this context. Since you mention
> it though, I still can't figure out why
> some pipework changes were made to the heating loop, so I'll ask here.
>
> Originally, on the pipework to and from the DHW cylinder coil, the
> connection to the top port had a 22mm expansion pipe branch going up
> to vent in the tank area.
> The bottom connection port had a 15mm supply pipe branch from the
> header tank.
> For some reason the plumber found it necessary to cut and cap off the
> 15mm supply pipe a couple of feet above the lower cylinder coil port,
Thinking about this on my dog walk I realised that in all liklihood, this is
the CH system feed (from a small header tank in the loft), not the CW feed
to the HW tank.
Does your new boiler have a pressure gauge and filling loop? If so, he's
converted you to a sealed system and that would explain the capping off of
the 15mm feed to te CH system.
> then join the supply from the header tank into the 22mm expansion pipe
> a little higher up in the airing cupboard.
Now that's still confusing me.
> All well and good not understanding the principle involved if things
> were ok but there seems to be a lot of air and gurgling in the loop
> now despite many bleedings.
At the end of the day, you had a working shower before the plumber visited,
now you don't. I don't think there's anything wrong with your shower valve
and I think you need to get the plumber back to sort it out.
Tim
treen...@googlemail.com
wrote:
Thanks for the thought you've put in Tim.
It was an an open vented system and remains so, though now it seems to
either pull in air or make gas.
I got down on my knees and begged my wife to agree to me fitting the
new boiler but she wasn't having any.
Admittedly it would have taken me a lot longer than the "experts",
during a particualrly cold spell.
So, I minimised the job to just a new boiler and got a local firm to
do it.
The main man on the job seems to have had one of his hands removed by
a mobile phone, poor bugger.
And the electrician apparently shouldn't have been there at all
because he was really management.
I was alarmingly unimpressed with the quality of the job but I won't
go into details.
I promised my wife I'd keep my mouth shut and not criticize while the
work was being done, or there would've been ructions.
I still can't work out why the expert joined the heating loop water
supply and vent pipe instead of leaving them to enter the loop
independently.
I suppose I could restore the original setup and see if it improves
the situation.
Regards,
Dick Treen
tim.d...@gmail.com
<treenoa...@googlemail.com> wrote:
> I suppose I could restore the original setup and see if it improves
> the situation.
I wouldn't. The original plumbers have a duty to get it right and if
they've bodged it, you should give them an opportunity to put it
right. I appreciate that you might not have much faith in them
sorting it but I would tell them that you want the system checked
*before* you get another plumber in to mend it at their expense.
If they don't fix it after that you have a good case to get another
plumber & charge the work to them (if their work is indeed faulty).
You may need to go through the small claims court. If you start
meddling yourself, you'll muddy the waters.
If you don't give them the opportunity you'll end up even more ot of
pocket.
Any chance of some photos?
Tim
treen...@googlemail.com
> On 25 Mar, 12:04, "treenoa...@googlemail.com"
>
> <treenoa...@googlemail.com> wrote:
> > I suppose I could restore the original setup and see if it improves
> > the situation.
>
> I wouldn't. The original plumbers have a duty to get it right and if
> they've bodged it, you should give them an opportunity to put it
> right. I appreciate that you might not have much faith in them
> sorting it but I would tell them that you want the system checked
> *before* you get another plumber in to mend it at their expense.
>
> If they don't fix it after that you have a good case to get another
> plumber & charge the work to them (if their work is indeed faulty).
> You may need to go through the small claims court. If you start
> meddling yourself, you'll muddy the waters.
> If you don't give them the opportunity you'll end up even more ot of
> pocket.
Thanks, point taken there.
> Any chance of some photos?
I'm going to be away for 10 days but I'll put up a photo when I get
back.
Regards,
Dick Treen