Immersion heater element length
Farmer Giles
problem is what length of element shall I get? I can already hear someone
saying, 'why don't you take it out first and have a look?' Well that makes
perfect sense, of course, but I need to travel a few miles to get a box
spanner to get it out first. When I go to get the spanner it would be much
easier - and quicker - to get the element at the same time.
The cylinder is about 15 years old and of the indirect type - although not
used in mode. It is 36 inches high and the element is fitted at the top. I
see two different lengths available at my supplier: 11 inches and 27 inches.
Which is it likely to be, or is there no way of being certain?
Thanks for any help.
ARWadsworth
"Farmer Giles" <Gi...@nospam.com> wrote in message
news:duCdnZc3YLXEAmTX...@brightview.com...
When the element is fitted from above it usually is the 27 inch version.
The 11 inch versions are fitted in the side and used on economy 7 setups.
Adam
Farmer Giles
"John" <jo...@idontlikespam.co.uk> wrote in message
news:jKKdnbXWTsrKIGTX...@bt.com...
> (like mine) is screwed onto the top (curved) surface I would imagine a 27
> "
> long one would foul against the opposite side of the cylinder when fully
> inserted. My cylinder is approx 4 foot tall and that definately has a 27"
> element Is it possible for you to get a fairly accurate measurement
> following the line of insertion, if you see what I mean.
I do see exactly what you mean - I'll try that. Many thanks.
Farmer Giles
"ARWadsworth" <adamwa...@blueyonder.co.uk> wrote in message
news:x1iKm.3688$Ym4....@text.news.virginmedia.com...
Looking at the angle of insertion - as suggested by John - it does look as
if the 27 inch one would fit ok. The only problem would seem to be is
whether or not it would come into contact with the heat exchanger.
ARWadsworth
> (like mine) is screwed onto the top (curved) surface I would imagine a 27
> "
> long one would foul against the opposite side of the cylinder when fully
> inserted. My cylinder is approx 4 foot tall and that definately has a 27"
> element Is it possible for you to get a fairly accurate measurement
> following the line of insertion, if you see what I mean.
>
The whole point of the immersion (apart from economy7 top up heaters) is
that it's lowest point is as low as possible to allow it to heat a full tank
of water.
Now if Farmer Giles wants only to heat a third of his cylinder and has a
very small bath he can fit an 11 inch immersion.
Adam
ARWadsworth
It will not come into contact with the heat exchanger.
OK so I have only swapped two immersions this year (it is a job I try to
avoid).
The threads align the immersion so that it does not touch the exchanger.
Adam
Farmer Giles
Thanks for that. I'll get the 27 inch one. In the [unlikely] event that it's
wrong, I suppose I can always take it back - be a nuisance, though!
shazzbat
Then the simplest answer would be to get one of each on the basis that you
can take back the one you don't use at your leisure.
Steve
Heliotrope Smith
27" is what you require for your indirect cylinder.
Farmer Giles
"shazzbat" <shaz...@spamlessness.fsnet.co.uk> wrote in message
news:hdcpej$rf1$1...@news.albasani.net...
taking things back to be exchanged but I don't like saying to them - "I
haven't used this one, can I have my money back please?"!
The Medway Handyman
Two tips. Start spraying the thread with WD40 or similar a few days before
you try to remove it. Buy the heaters at Wickes who have a no quibble
returns policy.
--
Dave - The Medway Handyman
www.medwayhandyman.co.uk
Farmer Giles
"The Medway Handyman" <davi...@nospamblueyonder.co.uk> wrote in message
news:WLuKm.3845$Ym4...@text.news.virginmedia.com...
Excellent tips, thank you. I was going to Screwfix, which is about 30 miles
away (we live out in the sticks!), and there is a Wickes nearby so I think
I'll do what you recommend.
AJH
Farmer Giles
"AJH" <out...@blueyonder.co.uk> wrote in message
news:7cc3b0f2-070e-453a...@w19g2000yqk.googlegroups.com...
> sometimes the length is printed on the label on the head part
All that's printed is 'NL27PT' - which does seem to suggest 27inch. I'm off
to get one now, I will report back.
Farmer Giles
It's a Newlec one. The Newey and Eyre website confirms that it is 27inch.
The 11inch ones are listed as 'NL11'.
Many thanks to everyone for the superb help and tips.
OJ
"The Medway Handyman" <davi...@nospamblueyonder.co.uk> wrote in message
news:WLuKm.3845$Ym4...@text.news.virginmedia.com...
>
seal' of the heater. The logic being that copper cylinders are a bit like
baloons - they need the internal pressure to give them strength. Is this
still accepted as the best way?
Thanks
OJ
ARWadsworth
"OJ" <o...@need.to.know> wrote in message
news:hdeenu$j8p$1...@north.jnrs.ja.net...
There is no need to drain the cylinder at all for this. Quite often there is
no means by which to drain the cylinder.
Drain or isolate the header tank and just catch any water that runs out from
the immerion hole with some towels.
Adam
ro...@cix.compulink.co.uk
adamwa...@blueyonder.co.uk (ARWadsworth) wrote:
> *From:* "ARWadsworth" <adamwa...@blueyonder.co.uk>
> *Date:* Tue, 10 Nov 2009 20:49:17 GMT
I had to change my bottom immersion (short) about a year ago. It had only
been fitted a few years ago. No matter what I did or used, I just couldn't
shift it. In the end I had to replace the whole tank. The long immersion
in the top (fitted at the same time as they were cheap, but never used)
was jammed solid as well. Really pxxxd me off as what was going to be a
half hour's job took over three days as the plumbing had to be altered to
fit the connections on the new tank.
Roger
Tinkerer
You may even be lucky and find an isolating valve twixt header tank and
cylinder. Mine has that and it makes life very easy.
--
Tinkerer
Tinkerer
Now you've got the hard bit. Unless you're lucky.....
--
Tinkerer
ARWadsworth
"Tinkerer" <invalid...@invalidaddress.invalid> wrote in message
news:hdf68u$smo$1...@news.albasani.net...
It takes no luck to find an isolating valve between the header tank and the
cylinder.
It takes good luck to find an isolation valve between the header tank and
the cylinder that actually works:-)
Adam
Farmer Giles
"Tinkerer" <invalid...@invalidaddress.invalid> wrote in message
Well I got the new element - it was the 27inch one - it is now fitted and
working ok. But you are correct, and I was a bit lucky! I can see that there
are many possible pitfalls and that some luck is needed. First of all (spot
on, Adam) there was an isolation valve between the header tank and the
cylinder - but the damn thing didn't work (not until some banging, WD40 and
lots of heat were applied anyway!).
Then came the actual job of getting the old one out - and it was a very old
one! - the cylinder was replaced in 1996, but I think that the immersion
element was much earlier and had been re-used. First of all the proper box
spanner that I got wasn't a very good fit - it was too big, I think that the
element flange hexagon was an imperial size. I had sprayed WD40 on it some
hours earlier - as recommended here, but I didn't have time to give days as
advised. Even after wedging the box spanner to get a decent fit, and tapping
it with a hammer, it still wouldn't budge.
Thankfully, after using the heat gun on it for a fair time (choking myself
on fumes from the cylinder lagging and setting off the smoke alarms in the
process!) I got it to move - hurrah! As I took it out I was surprised to
find the cylinder full to the brim - even though I had the isolation valve
closed and the hot taps open (with no water coming out of them). By placing
a couple of towels around the immersion heater hole and gently pulling it
out, I was able to clean up around the fitting and put the new element in
place without there being much water splashing about.
Yep, I think it could be a real sod of a job if things went badly wrong on
you. As it was I had real visions of having to replace the entire cylinder -
at around �200, not to mention loads of work and hassle - not a pleasant
prospect. Very grateful that it's done - and many, many thanks once again to
everyone for their help.
If I could pass on one or two tips on the basis of this experience, I would
say that:
1. Make sure that the isolation valve (if there is one) supplying the
cylinder is functioning ok before you start.
2. Tie up the ball valve of the expansion tank in the loft as a precaution -
better than turning off the cold water supply to the whole house (could be
while before it can be turned back on again!).
3. If your plumbing is quite old (like mine!), and things like stop taps and
isolation valves haven't been disturbed for a while, it might be worth
having a pipe freezer kit on stand-by.
4. Make sure that you have plenty WD40 and a heat gun available.
5. If the old element is quite stubborn to shift, and you need to give it a
few bangs with a hammer, make sure that the cylinder is full of water to
lessen the chances of damaging it.
6. Best of luck - you might need it!
ARWadsworth
As I took it out I was surprised to
> find the cylinder full to the brim - even though I had the isolation valve
> closed and the hot taps open (with no water coming out of them). By
> placing a couple of towels around the immersion heater hole and gently
> pulling it out, I was able to clean up around the fitting and put the new
> element in place without there being much water splashing about.
Why did that surprise you? I warned you.
The feed to the hot taps comes out of the hole at the top of the cylinder.
Adam
js.b1
- Alternate tighten/loosen with any stuck nut
- Fit an isolator ball-valve in the CW tank supply
- Check the terminals after 6 months for loosening - Neutral as well
as Live
Whilst on the subject of tanks, what is the min height for a
combination tank (CW+HW) above a sink/bath tap?
Farmer Giles
I know that. But, although they were open, water had stopped flowing from
the taps. Normally you can draw a fair bit of water from the hot taps even
though the supply is turned off - presumably half empty the cylinder! In
this case the isolation valve was working ok - although it wasn't to start
with - so why was the cylinder completely full when no water was coming out
of the taps?
ro...@cix.compulink.co.uk
Gi...@nospam.com (Farmer Giles) wrote:
> *From:* "Farmer Giles" <Gi...@nospam.com>
> *Date:* Wed, 11 Nov 2009 23:04:44 -0000
Unless there is a drain cock fitted on the cold water input to the
cylinder, you will never be able to empty the tank just by running the
taps if the hot water comes from the top of the cylinder (as is the normal
way of doing things).
Cold water comes into the bottom of the cylinder from the header tank in
the loft, and displaces the water from the top of the tank through the hot
water output at the top. If there is no drain cock fitted, the only way to
empty the cylinder is to loosen the cold water inlet pipe and continually
mop up the water as it leaks out of the cylinder. If the cold supply to
the cylinder and the bath tap are from the same pipe (ideally not, as this
would restrict the flow with the hot and cold taps running together),
turning the cold tap on would probably drain some of the water out of the
cylinder until it drops to the level of the tap.
When I replaced my cylinder, I made a T junction on the cold water inlet
pipe just before it went into the bottom of the cylinder. I reduced the
outlet to �" and connected a short piece of pipe with a blanking plug at
the end. I fitted an isolating valve between the junction and the blanking
plug. This method means that the blanking plug will ensure that there are
no leaks, even if the isolating valve is accidently turned on. The
isolating valve means that, after removing the blanking plug, I have
complete control of the water flow when I want to drain the tank. I then
just stick a hose where the blanking plug was and run it downstairs into
the garden.
If the isolating cock is between the header tank and the cylinder, turning
it off will prevent any water flowing into the cistern and the water
should stop flowing from the hot tap as you turn the cock off. If you only
turn off the water at the mains, then you would have to drain the header
tank as any water would still be able to flow from the header tank to the
cylinder.
Roger
ARWadsworth
Because you are asking water to flow uphill. Once the headertank is empty or
isolated there is no pressure to the tank to force the water out of the top
of the cylinder.
Adam
ARWadsworth
"js.b1" <js...@ntlworld.com> wrote in message
news:05b04213-8f7f-4548...@a32g2000yqm.googlegroups.com...
Not sure I have seen those tanks.
Adam
Farmer Giles
Of course. I was basing my (confused) thoughts on the fact that when we lose
our water supply here (a regular occurrence at one time) we can continue to
draw water from the hot taps for some considerable time. I realise now that
this is simply because the header tank is full and continuing to feed the
hot water cylinder.
Farmer Giles
<ro...@cix.compulink.co.uk> wrote in message
news:bcudnbsIhIzPyGbX...@giganews.com...
Thanks, I see all that perfectly clearly now. We do have such a drain cock,
as you describe, already fitted at the cold water supply to the cylinder. Of
course this would only needed if the cylinder needs to be replaced. As I
have already discovered, the heating element can be replaced without too
many problems even if the cylinder is full.
shazzbat
(S)He may be referring to something like "Harcopak instant plumbing". My
house, built 1973 ish, had this when we moved here. In the airing cupboard
was an angle iron frame with the cylinder in the bottom half, then a tank
above with a small tank in that for the heating feed. Both parts of this
upper tank were fed from the rising main, and each had a ball valve in it. I
think the house was built round it, when the tank leaked, I extended the
pipes up into the loft, put in two plastic tanks, and removed the
arrangement below. But even removing the airing cupboard door I couldn't get
it out. I had to cut the frame apart with an angle grinder, which of course
made me extremely popular.
Steve
Bob Minchin
manufacturer's name. Very popular for flat conversions to save running
pipes through upper flats to get to the lower ones.
To the OP: Provided the bottom to the combined tank is above the height
outlet tap and the pipe runs are as short as possible then there should
be adequate flow as this will give about 3'head. Ideally use 22mm pipe
to reduce the frictional losses. Useless for a gravity shower though so
either need a pump or easiest and electric shower.
Bob
Tinkerer
Oh ye of little faith. ;o)
--
Tinkerer
AJH
ARWadsworth
> thank goodness for combi boilers!
Is that because combi boilers never break down?
Adam
AJH
wrote:
> "AJH" <outw...@blueyonder.co.uk> wrote in message
Less to go wrong and no worries about get an unintended hot or cold
shower from a tank in the roof which gets full of crud, or a hot
water tank that doesn't vent properly!! Oh you also get an airing
cupboard when yu take the cylinder away!
shazzbat
Also it releases the tanks from the loft for use on the allotment. I now
have 6 of them collecting rainwater coming off the shed and greenhouse.
Whenever I see the signs of this work going on I stop and see what's been
thrown out on the drive or in the skip.
Steve
Andy Champ
>
> Less to go wrong and no worries about get an unintended hot or cold
> shower from a tank in the roof which gets full of crud, or a hot
> water tank that doesn't vent properly!! Oh you also get an airing
> cupboard when yu take the cylinder away!
Cupboard I see, as it is no longer half full of tank. But how does it air?
Andy
Martin
"Andy Champ" <no....@nospam.invalid> wrote in message
news:RZSdnVEzvMo9y53W...@eclipse.net.uk...
We put a small rad + TRV in ours - works a treat.
That said, we also put our cable modem & router plus their associated power
supplies in, too, so barely need the rad ...!
--
Martin
ARWadsworth
More chance of a combi failing than an immersion heater.
If you want the airing cupboard space then put the cylinder in the loft.
Adam
AJH
wrote:
> "AJH" <outw...@blueyonder.co.uk> wrote in message
>
> news:d91663dc-0ac4-4b4c...@r24g2000yqd.googlegroups.com...
>
>
>
> > On 13 Nov, 12:45, "ARWadsworth" <adamwadswo...@blueyonder.co.uk>
> > wrote:
> >> "AJH" <outw...@blueyonder.co.uk> wrote in message
>
> >>news:546160e6-8b58-4db4...@f16g2000yqm.googlegroups.com...
>
> >> > thank goodness for combi boilers!
>
> >> Is that because combi boilers never break down?
>
> >> Adam
>
> > Less to go wrong and no worries about get an unintended hot or cold
> > shower from a tank in the roof which gets full of crud, or a hot
> > water tank that doesn't vent properly!! Oh you also get an airing
> > cupboard when yu take the cylinder away!
>
> More chance of a combi failing than an immersion heater.
>
> If you want the airing cupboard space then put the cylinder in the loft.
>
> Adam
Why keep a tank constantly full of hot water at todays elec prices?
Andy Champ
>
> Why keep a tank constantly full of hot water at todays elec prices?
Because I have a bath full of water always available - and it costs
almost nothing to _keep_ it hot. (heating a new tankful is another matter)
No electric system will give you a bath full at 5 minutes notice.
Andy
ARWadsworth
Most cylinders are heated by a regular or system boiler and so heated at gas
prices and not at electric prices.
If the regular/system boiler fails (far less to go wrong than a combi) then
you have an immersion as a backup.
The hot water for a house is best delivered by what is wanted or needed.
A single person or a couple living in a flat or small house may be OK with a
combi.
A family of 4 in a 4 bed house with ensuites csnnot use a combi and say that
their HW experience is good.
There are pros and cons to all setups.
Adam
Burbeck
b#'[]#';'s. there are a few tricks
regards
bob
steve.t...@hotmail.co.uk
cryptogram
>
> > >>>>>
>>>>> news:duCdnZc3YLXEAmTX...@brightview.com...
> >>>>>> The immersion heater element in my hot water cylinder has failed. The
> >>>>>> problem is what length of element shall I get? I can already hear
> >>>>>> someone saying, 'why don't you take it out first and have a look?'
> >>>>>> Well that makes perfect sense, of course, but I need to travel a few
> >>>>>> miles to get a box spanner to get it out first. When I go to get the
> >>>>>> spanner it would be much easier - and quicker - to get the element at
> >>>>>> the same time.
> >>>>>>
> >>>>>> The cylinder is about 15 years old and of the indirect type -
> >>>>>> although not used in mode. It is 36 inches high and the element is
> >>>>>> fitted at the top. I see two different lengths available at my
> >>>>>> supplier: 11 inches and 27 inches. Which is it likely to be, or is
> >>>>>> there no way of being certain?
> >>>>>>
> >>>>>> Thanks for any help.
> >>>>>
> >>>>> version.
> >>>>>
> >>>>> The 11 inch versions are fitted in the side and used on economy 7
> >>>>> setups.
> >>>>>
> >>>>
> >>>>
> >>>> Looking at the angle of insertion - as suggested by John - it does look
> >>>> as if the 27 inch one would fit ok. The only problem would seem to be
> >>>> is whether or not it would come into contact with the heat exchanger.
> >>>
> >>> It will not come into contact with the heat exchanger.
> >>>
> >>> OK so I have only swapped two immersions this year (it is a job I try to
> >>> avoid).
> >>>
> >>> The threads align the immersion so that it does not touch the exchanger.
> >>>
> >>> Adam
> >>
> >> Thanks for that. I'll get the 27 inch one. In the [unlikely] event that
> >> it's wrong, I suppose I can always take it back - be a nuisance, though!
> >>
> >>
> >
> > Then the simplest answer would be to get one of each on the basis that you
> > can take back the one you don't use at your leisure.
> >
> That makes perfect sense, of course, except for the fact that I don't mind
> taking things back to be exchanged but I don't like saying to them - "I
> haven't used this one, can I have my money back please?"!