Honeywell V4073A1062 (was, erroneously V4073A6022) follow up

[Johnny B Good]

Just thought I'd add a few extra thoughts on solving my zone valve
problem(s).

First off being to correct the part number (Doh!). The second being that
the perceived wisdom of replacing the complete valve assembly instead of
using the upgrade kits when both the rubber ball *and* the synchron motor
need to be replaced[1] doesn't always apply since it isn't always the
most economic economic measure based on the grounds that two such kits
can work out dearer than the cheaper 22mm compression fittings only
version of the V4073A.

Whilst this would be true when all the pipework is 22mm, this is not the
case when, as in my system, two of the pipes are 28mm requiring
additional space consuming adapters or else the acquisition of the more
expensive original V4073A1062 'drop-in' replacement part (£100 + VAT!).

I can buy the necessary 40003916-003 replacement powerhead from Amazon
for a 'mere' £37.89 & FREE Delivery and the Honeywell 40003918-007
Conversion / Repair Kit from heatingcontrolsonline for a mere £18.71
(vat inclusive price) with economy delivery of £2.99 +VAT (£3.59) making
a total expenditure in this example of £60.19, just under half the cost
of an original V4073A1062 and right in the ballpark of a cheap 22mm only
V4073A.

It may even be possible to effect an even cheaper repair if it proves
possible to cannibalise the ball part from the the Honeywell 40003918-007
Conversion / Repair Kit leaving me the option of fitting a 10 quid
replacement synchron motor for the original motorhead.

I'll check out my local CH/Plumbing suppliers for the the Honeywell
40003918-007 Conversion / Repair Kit first before ordering on line. I
might be able to ascertain the viability of cannibalising the ball part
without having to place an on-line order if my local supplier is obliging
enough to disclose this option (or let me 'finger the goods').

[1] I mentioned the peculiar effect that the spring return was
detrimentally effected by the orientation of the unit. This should have
been all the hint I needed to determine that the gearbox bearings were
badly worn after all and that a replacement synchron motor would be a
wise investment.

That doesn't change the fact that the primary culprit remains the poor
condition of the rubber ball making this a prior condition to any
investment in a new motor.

--
Johnny B Good

[Etaoin Shrdlu]

I managed to cure a similar problem (radiators coming only the hot water
should be) by just scraping the magnetite from around the port holes.
Of course, if the ball in yours is visibly worn, it's probably not worth
taking the chance, seeing that you have to drain the system to try each
fix. But if your ports look black, give them a gentle scrape.

[Graham.]

I was going to suggest the same as Roger Mills, that you should
consider using a pair of two port valves, and configuring the pipework
as an "S" plan.

My pair of Honeywell valves are 40 years old! The actuator heads are
non removable.

Shades of the Ship of Theseus (or Trigger's Broom), I have replaced
their motors and microswitches several times over the years, but the
"wet" valve part are both original and have never given any trouble.

I have never dismantled a three port type, but I know they are
regarded as less reliable than the two port version. There isn't a
rubber ball gismo in mine.

--

Graham.

%Profound_observation%

[Johnny B Good]

On Mon, 13 Jul 2015 18:00:12 +0100, Etaoin Shrdlu wrote:

> Johnny B Good wrote:
>>
>> Just thought I'd add a few extra thoughts on solving my zone valve
>> problem(s).
>>
>> First off being to correct the part number (Doh!). The second being
>> that
>> the perceived wisdom of replacing the complete valve assembly instead
>> of using the upgrade kits when both the rubber ball *and* the synchron
>> motor need to be replaced[1] doesn't always apply since it isn't always

>> the most economic measure based on the grounds that two such

Thanks for that advice, Etaoin [1].

I did scrub the pipe openings and the innards of the valve body with one
of those miniature brass wire brushes to clean the black coating off,
mainly concentrating on the pipe entry points to ensure a leak free
fitting.

I can't recall how thorough I was in cleaning the valve seats themselves
so I'll be checking those when I next pull the valve out of the pipework
to finish the repair. Obviously, making sure that the valve seats are
crud free will be a vital part of the ball replacement exercise so your
'heads up' is well appreciated.

I'm not too bothered by having to part drain down the system for this
job. Indeed, I only bothered refitting the valve and refilling in order
to check whether my 'fettling' by itself had provided any sort of
improvement, being the optimist that I am. The best I could say was that
I hadn't made it (noticeably) any worse. :-(

If my sense of optimistic curiosity hadn't got the better of me, I'd
have happily left it in a state of disassembly since we're at that time
of the year when it can remain that way for the next two or three months
and I can seek the parts at my leisure with absolutely no urgency
whatsoever. A rare privilege as far as most CH/HW system DIY repair jobs
tend to go, a privilege I intend to enjoy to the full. :-)

In the meantime, I've narrowed down my options to fitting a new rubber
ball (ideally, sourced from a supplier who supplies *just* the rubber
ball on its own but more likely a case of cannibalising one from the
later repair conversion kit circa 20 quid) and replacing the worn out
synchro motor (13 quid or so from my local ToolSatan).

I have grave doubts as to being able to buy just the ball on its own so
will likely go for the repair kit and hope the ball can be swapped into
the old valve body. If this turns out to be a No-Go, I'll simply order a
new controller head to allow me to use the repair/upgrade kit as
intended. Since I'm in no hurry, I can afford to order these items
separately according to *actual* need. If I'm very lucky, it might only
cost me a 13 quid motor and a 19 quid repair/upgrade kit.

I was hoping that someone might have been able to confirm whether
replacement balls on their own are still, if they ever were, an available
option or, alternatively, whether the ball used by the repair/upgrade kit
is the same as the one used in the original design.

It certainly looks a very good possibility but I have no definite proof
this will be true. No doubt the ball will be the same diameter but
Honeywell might well have had the foresight to use a different sized
spindle in order neatly sabotage any attempts by skinflint DIYers to
effect a really cheap repair and to enhance sales of replacement power
heads. I may find out soon enough if they'd had the wit to close off such
a relatively cheap repair route.

To further complicate things, when I was perusing ToolSatan's book of
parts, I noticed a cheaper 3 port motorised zone valve with 28mm
compression fittings made by Sunvic for a mere £63.93 (VAT inclusive
price) which looks like a drop in replacement for the Honeywell part.
Having to fit a 28mm to 22mm reducer on the HW port being the only minor
(if technically acceptable) downside AFAICS. I noticed they also offered
a Corgi 3 port mid position valve for a mere £49.88 but only in the 22mm
compression fitting version.

The Sunvic part omits the phrase 'mid position' but the picture shows
the marking "Uni-share" in between arrows pointing to the A and B ports
which may simply mean it can only operate in a simplex mode (either/or)
or a badly phrased indication that it can *share* the flow (as in split
it).

I guess I'm going to have to do more searching on parts/model numbers to
get the required detailed info on these items[2] before I can make a
final decision. As much as I'd like to 'drill down' to the most optimal
repair solution, given the massive amount of time I can squander on this
quest, I'm still tempted to shell out a reasonable wodge of cash on a
"quick fix" if only to to get it over and done with, provided the extra
spend isn't too excessive compared a viable 'cheapest repair' option.

That 40003916-003 replacement powerhead from Amazon for a 'mere' £37.89
& FREE Delivery isn't actually made by Honeywell but by a company called
Banico. The pictures reveal the model number to be H-ZVM with the
description "Actuator for mid-position valves" and it looks like a very
good 'Chinese Copy' of the Honeywell part. Strangely, amongst the many
variants of the V4073A it can replace, it includes the 1062 version which
can only be true after the upgrade/repair kit has been fitted.

The worrying thing is that just about every on-line supplier quotes
anywhere from 65 quid plus VAT right up to 80 quid plus VAT for the
Honeywell part. The price looks almost too good to be true except for the
fact that we all know how much piss take is factored into the retail
pricing of Honeywell parts (and that of the other major Central heating
parts manufacturers).

They say you get what you pay for but in this case, both the Banico and
the Honeywell powerheads seem to be using identical tin boxes and the
actual motor/gearbox used is the identical design that's been around for
the best part of the last half century and, like the microswitches, must
be commodity parts of pretty well identical quality (but I'm prepared to
be corrected on this matter - comments anyone?).

I'm rather hoping I can report a final outcome that confirms that the
ball in the repair/upgrade kit *does* fit the older valve after all,
meaning a cheaper repair can be effected by a new motor and the repair
kit without the need to spend money on a whole new powerhead. Something
well worth knowing if it turns out to be true. :-)

Whatever the outcome, I'll report back. It'll still be useful to know
that the repair/upgrade kit can't be utilised in this way - saves any
pointless speculation by others who may be tempted by this possibility in
the future.

[1] I'd have used a more user friendly name if you had offered one in
your missing sig line but I guess we're stuck with the typesetter's "Fill-
in" text used to place-mark errors.

[2] One piece of *useful* info would be the overall dimensions to
determine whether or not I'd need to 'stretch' the existing pipework to
reach the couplings. More measurements and more googling it is then. :-(

--
Johnny B Good

[Johnny B Good]

That's useful to know (sadly, in hindsight - that 3 port mid-position
valve provided good service for the first two decades of its life before
gracefully failing - no sudden catastrophic failure). The S plan option
is a choice best made in the initial implementation it seems to me.

Considering that the rest of the CH system will be half a century old by
the time a new valve has clocked up a couple of decades of trouble free
service, such an upgrade may well fail to realise its full RoI value when
the rest of the system around it starts expiring from old age. In any
case, the cost of the parts would have to be at least as low as that of a
replacement V4073A1062 before I'd even consider such a job.

BTW, I wonder what those 2 port valves use in place of a rubber ball?
Could it be as simple as a rubber faced disc attached via a ball joint on
the end of an actuator arm?


--
Johnny B Good

[Johnny B Good]

On Tue, 14 Jul 2015 02:03:32 +0000, Johnny B Good wrote:

====huge snip====

>
> They say you get what you pay for but in this case, both the Banico and
> the Honeywell powerheads seem to be using identical tin boxes and the
> actual motor/gearbox used is the identical design that's been around for
> the best part of the last half century and, like the microswitches, must
> be commodity parts of pretty well identical quality (but I'm prepared to
> be corrected on this matter - comments anyone?).
>
> I'm rather hoping I can report a final outcome that confirms that the
> ball in the repair/upgrade kit *does* fit the older valve after all,
> meaning a cheaper repair can be effected by a new motor and the repair
> kit without the need to spend money on a whole new powerhead. Something
> well worth knowing if it turns out to be true. :-)
>
> Whatever the outcome, I'll report back. It'll still be useful to know
> that the repair/upgrade kit can't be utilised in this way - saves any
> pointless speculation by others who may be tempted by this possibility
> in the future.
>

I popped into my local "Plumb Centre" this afternoon and got an
excellent deal on the Honeywell 40003918-007 Conversion / Repair Kit,
just 13 quid and a few pence. It's on overnight order and will be ready
to collect up first thing tomorrow morning after 8 am. Mind you, I won't
be strolling in at that sort of time, maybe around 9 or 10 am but it's
more likely to be a mid afternoon visit.

Once I've got my mitts on the kit, I should be able to see which way to
jump (cheap synchron motor from Toolsatan up the road or an internet
order for the Banico powerhead). Once I know, you'll all know. :-)

--
Johnny B Good

[Johnny B Good]

Well, I finally finished the repair this afternoon. My idea of
cannibalising the rubber ball from the repair kit turned out to be a non-
starter.

As it turned out, not as bad an outcome as I'd feared since I was able
to source a replacement control head (a Corgi Replacement actuator)[1]
quite cheaply from, of all places, my local Toolstatan (2 1/2 mile round
trip, something like 60p's worth of unleaded) for a mere £31.93.

This was £1.02 cheaper than the cheapest ebay alternative that I liked
the look of, a TMS MOTORISED ZONE VALVE ACTUATOR HEAD from an outfit
called "Team Supplies". The detachable cable was a nice touch mind, so
the extra £1.02 could have been justified for this 'convenience feature'
alone - handy except I don't expect to be making very much use of it
considering the anticipated decade or so 'servicing interval'.

The Free Click and collect from Argos meant an extra 6 day wait that ICBA
putting up with, even though it puts the 'collection cost' on a par with
that of calling into Toolsatan's trade/retail counter. Still, for anyone
contemplating a similar repair, that might be a useful thing to know if
they don't have a local Toolsatan within just a few miles of home.

As it happened, I ended spending around £1.20 on unleaded since I had to
return the Corgi replacement actuator as defective on account operating
the auto to manual lever (used to assist fill up / drain down and, in
this case, removal/refitting to the valve body) caused the sector plate
to jump teeth on the motor cog wheel.

Removing the cover revealed the single motor unit retaining screw was
slack to the tune of about 1 1/2 turns and what appeared to be crud on
the cog wheel and sector plate with a spot of green where the sector
plate engaged the cog. Tightening up the slack fixing screw made no
difference to the symptoms so I returned it for a replacement with a very
quick check at the counter suggesting it was ok (much better than the
'faulty unit' at any rate).

When I got back to base and took a closer look at the replacement, I saw
the same whitish crud, complete with green spot and could still elicit
cog jumping (the motor fixing screw in this case was only an eighth of a
turn slack).

It was only on closer inspection with my trusty jeweller’s loupe that I
realised that the 'crud' was in fact grease and the reason for the cog
jumping was simply the lack of support on the sector plate bearing from
the valve spindle which would normally prevent the problem once the
controller head was firmly attached to the valve body (Doh!!!).

So, a word to the wise when setting it into the 'manual' position prior
to attaching it to the valve body, the tendency to cog jumping is normal
in this circumstance. Once it's attached there shouldn't be any further
trouble in this regard (unless you're being particularly brutal in
operating the lever).

At the end of the exercise, the total parts cost came to a pretty
reasonable £45.01 [2]. I reckon the time spent plus a fiver or so's worth
of unleaded (and 4 quid for a 1 1/2 inch AF spanner) was simply the price
of 'learning the mysteries of CH repair'.

Apropos of which (mysteries of CH plumbing), I think I've finally
figured out the true purpose of the short length of 15mm pipe teed off
the 28mm pump outlet which goes, via a valve, straight onto the 22mm
return from the hot water tank heating coil circuit.

Until I read the instructions about the true purpose of the auto/manual
lever on the control head relating to facilitating refill/drain down, I'd
just assumed it was some arcane flow balancing measure so, playing safe,
I've never risked completely shutting the valve off.

Now, I'm inclined to believe that it's only function is to also
facilitate refill/drain down operations and should normally be completely
closed off. I now have it fully shut off but would like some confirmation
that this is how it's normally supposed to be set. I suppose I could try
some more bing/google/duckduckgo-ing for this information but a hint or a
link to a wiki would be very welcome right about now. :-)

[1] What staggers me in regard of all the different brands/models of 3
port mid position zone valves and their "detachable without needing a
drain down" control heads is their seemingly universal compatibility with
the Honeywell V4073A zone valve.

It wasn't too obvious when I first set off on this saga but it seems to
me you'd be very hard pushed to find a 3 port mid position zone valve
that *wasn't* Honeywell compatible. :-)

[2] If I buy a couple of 4 litre packs of Fernox MB1 to dose this 13
radiator system as I've done in the past (I'm estimating a 6 litre
requirement since our Heating system plumbing is notably more extensive
than the typical 100 litre 10 radiator semi detached house installation
(Basement boiler, ground, first and second floor radiators), I could
easily land up spending more on inhibitor than parts and that's excluding
a flushing out of the system with a cleaning additive!

Quite frankly, I'm tempted to try the much cheaper additives being sold
by Toolsatan who I notice, btw, *don't* sell any of the Fernox product,
just the Corgi, Qual-Rad and CalChem product.

Is the Fernox product really worth its premium price or could I do just
as well using the cheaper alternatives?

--
Johnny B Good

[Roger Mills]

On 15/07/2015 23:23, Johnny B Good wrote:

>
> Well, I finally finished the repair this afternoon. My idea of
> cannibalising the rubber ball from the repair kit turned out to be a non-
> starter.
>
> As it turned out, not as bad an outcome as I'd feared since I was able
> to source a replacement control head (a Corgi Replacement actuator)[1]
> quite cheaply from, of all places, my local Toolstatan (2 1/2 mile round
> trip, something like 60p's worth of unleaded) for a mere £31.93.
>

Now I'm confused!

My understanding of these valves is that there are two part - the 'wet'
part which directs the flow to either or both output ports, and the dry
part - the electrical actuator with motor and micro-switches which
drives the shaft of the wet part in order to achieve the desired effect.

From what you have said, your problem was with a worn rubber ball -
which is a component of the wet part, but you have only replaced the dry
part and still have the worn ball in situ.

I may be missing something, but I'm struggling to see how that is going
to solve your problem.
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

[Johnny B Good]

I did mention this key information, easily missed in a 48 line post I
suppose. :-(

Honeywell 40003918-007 Conversion / Repair Kit

This is a new plate with actuator arm and rubber ball, supplied with a
new O ring seal, and the the four "special screws" (two are hex headed
with tapped drilled holes into which the captive retaining screws of the
later control head screw into and the remaining two screws, also hex
headed, have a locating pip which line up with holes in the control head
base plate).

Fitting this Honeywell 40003918-007 Conversion / Repair Kit requires the
use of the later control head designed to allow replacement without
having to drain down the system beforehand as was the case with the older
valve/control head unit I was trying to repair.

It's described as a Conversion / Repair kit because it can be used to
upgrade an existing valve, retaining only the rather meaty brass valve
body or else allow a simple replacement of the rubber ball part
(including the actuator spindle and bearing assembly plate) on the later
or converted valves.

In my case, I'd had the forlorn hope that I'd be able to cannibalise the
rubber ball from that kit, thus reducing the parts cost to that of the
kit plus a cheap replacement motor for the existing control head. As it
happened, I was left without such a choice and had to buy a complete
control head unit, an option that turned out to be far cheaper than the
on-line pricing of the "Honeywell" control heads at 65 to 80 quid a pop.

In the end, the repair costs via the 'expensive' and 'messy' route of
upgrading the valve using two seperate parts kits proved surprisingly
more economic than the "Just shell out 120 quid for an original
replacement and have done with it" approach. :-)

It just goes to show that embarking on such Central Heating
refurbishment work during the lazy days of summer allows you ample time
to properly search out an effective and economic solution (and learn some
valuable lessons along the way).

BTW, I'm a little disappointed that no one has offered any advice over
the question of "Fernox versus the rest". I think I should post that as a
seperate thread.

--
Johnny B Good

[Roger Mills]

I guess I read your earlier post as "the ball didn't fit" whereas I
think you're saying that it *does* fit - but only if you fit the whole
kit rather than just the ball - and that that then requires the actuator
to be replaced as well. Is that right?

[Interesting as your posts are, you do tend to use 100 words where 10
would do, and a quick scan sometimes results in the salient points being
missed].

[Johnny B Good]

On Fri, 17 Jul 2015 11:43:24 +0100, Roger Mills wrote:

> On 17/07/2015 01:07, Johnny B Good wrote:

====snip====

>>
>> In the end, the repair costs via the 'expensive' and 'messy' route of
>> upgrading the valve using two seperate parts kits proved surprisingly
>> more economic than the "Just shell out 120 quid for an original
>> replacement and have done with it" approach. :-)
>>
>> It just goes to show that embarking on such Central Heating
>> refurbishment work during the lazy days of summer allows you ample time
>> to properly search out an effective and economic solution (and learn
>> some valuable lessons along the way).
>>
>> BTW, I'm a little disappointed that no one has offered any advice
>> over
>> the question of "Fernox versus the rest". I think I should post that as
>> a seperate thread.
>>
>>
> I guess I read your earlier post as "the ball didn't fit" whereas I
> think you're saying that it *does* fit - but only if you fit the whole
> kit rather than just the ball - and that that then requires the actuator
> to be replaced as well. Is that right?

Spot on! :-)

I was, in my usual overly optimistic way, hoping I could acquire a
replacement ball from the kit to replace the worn one without actually
having to fit the whole kit, thus neatly avoiding the need for a
replacement compatible control head (just a much cheaper motor to
refurbish the old unit).

>
> [Interesting as your posts are, you do tend to use 100 words where 10
> would do, and a quick scan sometimes results in the salient points being
> missed].

That's a fair point (despite the use of hyperbole - more like 100 words
where 70 might do :-).

My problem isn't the wordage so much as line-age. I feel that a usenet
response shouldn't have the obscene look of a twitter post, it deserves
so much more than that. Trouble is, I find myself going a little too far
most times. In some news groups this isn't a major problem but in others
such as uk,d-i-y, it's all too easy to create a forest of verbiage
swamping the salient 'wood-en' points wherein the reader may well feel
they couldn't see the wood for the trees.

It's not as though I don't appreciate this problem with others' overly
long posts it's more a case of pandering to a selfish desire 'to explain
all' by 'just a *few* extra words on the matter is all it'll take - what
harm can it do?' and before I've realised it, I've typed yet another
massive missive.

I sometimes redact whole paragraphs when it dawns on me whilst proof
reading... er admiring my handiwork what a monster of a missive I've
created. I do sometimes keep it short and sweet. This is not one of those
times but I'd like you to consider these last 3 paragraphs as a sort of
apology if you may. :-) (a smiley - that should make it all right).

--
Johnny B Good

[Andy Burns]

Johnny B Good wrote:

> That's a fair point (despite the use of hyperbole - more like 100
> words where 70 might do:-). My problem isn't the wordage so much as
> line-age.

I'm beginning to suspect you wear a bow-tie at work :-P

[Johnny B Good]

It's often enough said that "Appearances can be deceiving". This is one
such case. Even before I went 'self employed' 19 years ago, I never ever
wore a bow-tie to (or at) work. In fact, even on those occasions
(weddings, funerals etc) when I *was* obliged to 'get suited up', I
*still* never wore a bow-tie, just an ordinary neck-tie... under
sufferance.

We all have 'our vanities' (expressed in various forms). In my case,
mine (let us say) is more of an intellectual form which doesn't extend to
any great concern over my physical appearance which, btw, I consider to
be just the scruffy side of 'tidy' (not 'Neat and Tidy' please note).

I'm sure others would simply describe me as 'scruffy', an opinion I
prefer to think of as one arrived at without due consideration for any
precision on their part. :-)

However, that is all a matter of opinion and, as someone else so
succinctly pointed out, "Opinions are like arseholes, we all have one!"

Just as we're not obliged to like arseholes, as long as we can respect
that each of us cannot function without one, there's neither sense nor
need in letting opinion (or, indeed, arseholes) cause upset and distress.

Having proof read that last bit, it's just occurred to me that the above
could be misconstrued as 'a clever attack on your opinion'. Let me assure
you that this couldn't be any further from the truth. I was merely
seizing the opportunity to recycle someone else's rather pithy
observation about opinions in general to inject a bit of humour.

Taking a brief step back, I can understand your (sneaking?) suspicion as
to my wearing a bow-tie at work. However, I hope I have now well and
truly succeeded in dispelling this suspicion. :-)

BTW (getting back on topic), do you happen to have any strong opinion
with regard to Fernox MB1 corrosion inhibitor versus all the rest of the
much cheaper competing products?

And, touching on the mysteries of CH plumbing, is the valve in that 15mm
shunt from pump outlet to HW return simply there to facilitate drain down
and filling?

--
Johnny B Good

[Roger Mills]

On 18/07/2015 16:13, Johnny B Good wrote:

>
> And, touching on the mysteries of CH plumbing, is the valve in that 15mm
> shunt from pump outlet to HW return simply there to facilitate drain down
> and filling?
>

A picture - which, as you know, is worth 1000 words(!) - would be nice.

In the absence of a picture, my suspicion is that it's a manual by-pass
- designed to provide a flow path in CH-only mode in cases where the
TRVs on all the rads are shut. The valve will allow the effective size
of the by-pass to be adjusted to prevent too much flow going that way
under normal circumstances. If you need a by-pass valve at all, an
automatic one would be better. Does your boiler need pump over-run? Can
there ever by *no* path through the radiators? Unless the answer to both
questions is 'yes', I don't think you need a by-pass.

I don't see how your 'shunt' pipe would facilitate drain down or
filling. Using the manual lever which moves the 3-port valve to the mid
position is the way to do that.

[Johnny B Good]

On Sat, 18 Jul 2015 17:59:32 +0100, Roger Mills wrote:

> On 18/07/2015 16:13, Johnny B Good wrote:
>
>
>> And, touching on the mysteries of CH plumbing, is the valve in that
>> 15mm
>> shunt from pump outlet to HW return simply there to facilitate drain
>> down and filling?
>>
>>
> A picture - which, as you know, is worth 1000 words(!) - would be nice.
>
> In the absence of a picture, my suspicion is that it's a manual by-pass
> - designed to provide a flow path in CH-only mode in cases where the
> TRVs on all the rads are shut. The valve will allow the effective size
> of the by-pass to be adjusted to prevent too much flow going that way
> under normal circumstances. If you need a by-pass valve at all, an
> automatic one would be better. Does your boiler need pump over-run? Can
> there ever by *no* path through the radiators? Unless the answer to both
> questions is 'yes', I don't think you need a by-pass.
>
> I don't see how your 'shunt' pipe would facilitate drain down or
> filling. Using the manual lever which moves the 3-port valve to the mid
> position is the way to do that.

Thanks, Roger.

Point taken about the "Thousand words Picture", I don't think such a
picture will be needed in this case. :-)

By "pump over-run", do you mean pump run on after the boiler has shutdown
at the end of a selected period of heat/hot water output? I don't believe
pump over-run was a feature of this system which uses an Ideal Mexico
Super CF100 floor standing boiler.

With regard to the "Mystery Valve" did rather think it may have been
some arcane flow bypass thing when I had my first fiddle with it about 25
years ago when looking for valves in the system to try out the couple of
red painted valve wheels on that had been left with us as 'spare items'
by the CH installers.

I can't honestly say, but Istr, this particular valve had been left in a
partially open position which, after exercising it from fully open to
fully closed, I left set in a position as close to its original setting
as I could recall at the time.

It did rather upset my engineering sensibilities that such an arcane
flow control technique was being employed at the expense of pumping
efficacy but decided discretion would be the better part of valour in
this case. Back then, usenet and googling for an answer to this conundrum
was out of the question.

However, we do have *one* radiator *not* tricked out with a TRV in the
system - the other 12 rads do each have a TRV. This is a heated towel
rail in the downstairs shower room.

Prior to a major revamp of the shower room about 5 years ago, it was the
originally fitted radiator which I'm pretty certain also lacked a TRV so
it seems have been selected to act as the by-pass radiator from the start
(the lack of a TRV proving to be a deliberate choice rather than a cost
cutting exercise or an oversight).

When the system was originally installed reliance for thermo regulation
was placed entirely onto the TRVs and the boiler stat. The hot water
cylinder has its own stat to stabilise the hot water temperature. There
simply isn't a seperate room stat wired to the CH/HW control unit (a
Potterton 2000).

I'm second guessing that your next bit of advice would be to crack open
that mystery valve a half turn or so. :-)

--
Johnny B Good

[Roger Mills]

On 18/07/2015 23:12, Johnny B Good wrote:

>
> I'm second guessing that your next bit of advice would be to crack open
> that mystery valve a half turn or so. :-)
>

No - the exact opposite! I suspect that the by-pass serves no useful
purpose - so I'd *close* the valve completely and see what happens.

If there are no obvious ill effects after a week or two (of normal
winter operation), leave it closed.

[Andy Burns]

Johnny B Good wrote:

> do you happen to have any strong opinion
> with regard to Fernox MB1 corrosion inhibitor versus all the rest of the
> much cheaper competing products?

Not really, What's sloshing around in my system is Screwfix cheapish stuff.

[Johnny B Good]

On Sun, 19 Jul 2015 18:08:25 +0100, Roger Mills wrote:

> On 18/07/2015 23:12, Johnny B Good wrote:
>
>
>> I'm second guessing that your next bit of advice would be to crack
>> open
>> that mystery valve a half turn or so. :-)
>>
>>
> No - the exact opposite! I suspect that the by-pass serves no useful
> purpose - so I'd *close* the valve completely and see what happens.
>
> If there are no obvious ill effects after a week or two (of normal
> winter operation), leave it closed.

I'm inclined to the same view but it might have been installed as a
"Belt 'n' Braces" addition and also might possibly have something to do
with the 22mm gate valve in the HW heat exchanger flow side coming from
the 3 port mid position zone valve.

I've just confirmed that it's still set in a mid position (neither on or
off) which implies that it's a flow balancing adjustment between the
heating and the hot water circuits when both are selected from the
controller, especially since there isn't a similar valve on the return
circuit to allow it to be used for isolation purposes.

There aren't any other such 'mystery valves' in the airing cupboard, btw,
so no further surprise unknowns for you to consider (but I expect such a
valve wouldn't be considered as such anyway - just thought I'd better
mention it in case it mattered).

--
Johnny B Good

[Johnny B Good]

One of the great unknowns, to me at least, is just how often are you
supposed to 'freshen up' (or completely refill and re-dose) the system
with these various brands of inhibitor?

I mean, are we talking about (in a soft water area for example) having
to refresh every two or three years with a cheaper brand versus (as best
as I can figure - see my post "Fernox or not?") every ten to twenty years
with Fernox MB1?

If you have any thoughts to offer on this, it might be better to post
into the "Fernox or not" thread. :-)

--
Johnny B Good

[Roger Mills]

On 20/07/2015 00:30, Johnny B Good wrote:

>
> I'm inclined to the same view but it might have been installed as a
> "Belt 'n' Braces" addition and also might possibly have something to do
> with the 22mm gate valve in the HW heat exchanger flow side coming from
> the 3 port mid position zone valve.
>

No, the 22mm gate valve will be a HW vs CH balancing valve to prevent
the HW taking more than its fair share of the flow when the 3-port valve
is in the mid-position.

[Graham.]

On Tue, 14 Jul 2015 02:42:05 GMT, Johnny B Good

The pinion of the motor/gearbox meshes with a curved spring-loaded
rack (if you can have curved rack) this directly opens the valve.
A leaver that protrudes at one can push the rack and mechanically
latch it open. No perishable parts to be seen unless they are in the
wet part which is not dismantlable AFAICS

--

Graham.

%Profound_observation%

[Johnny B Good]

On Thu, 23 Jul 2015 22:59:34 +0100, Graham. wrote:

> On Tue, 14 Jul 2015 02:42:05 GMT, Johnny B Good
> <johnny...@invalid.ntlworld.com> wrote:
>
>>On Mon, 13 Jul 2015 19:40:08 +0100, Graham. wrote:

====snip====

The curved spring loaded rack, I believe, is called a 'sector gear
plate', basically just a wedge like slice of the bit of the larger cog
actually required.

The old type valve requires a drain down to allow removal of the control
head since it's part of the end plate which carries the rubber ball
actuating crank and water tight bearing that it runs in. I found I could
readily slip the ball itself off of the crank pin which gave me an
optimistic hope that it was possible to buy replacement balls to fix this
problem (this may have been true originally but the advent of the newer
detachable, without draindown, control head effectively obsoleted the
need).

I had hoped, however, that the ball used in the newer variant could be
cannibalised from the repair/upgrade valve plate kit but Honeywell had
made damn sure any such cheap repair wasn't going to be possible by
changing the crankpin diameter to a slightly smaller one and use a
riveted end washer to prevent ball removal anyway.

When I saw this, I was then forced to buy the later type of control head
to complete the valve assembly upgrade. This turned out a lot cheaper
than I'd initially feared would be the case, and, from a surprisingly
local source, Toolstation of all places!

BTW, I did learn something useful from this exercise, it would seem to
be impossible to buy an incompatible control head for the later version
of the Honeywell 3 port mid position valve. No matter what make or
branding the control head may be, as long as it's for a three port mid
position valve, it'll fit and operate just as well as any of the 65 to 80
quid Honeywell control heads (the Toolstation one was a mere £31.93 btw).

The parts total came to a mere £45.01 after all of my researching for
the 'Cheapest possible solution' (13 quid for the repair/upgrade kit and
32 quid for a new control head unit) which was a damn sight cheaper than
buying a complete Honeywell valve assembly for around the 115 to 120 quid
mark.

The job's done now and all I'm waiting on is getting up the gumption to
re-dose the system with another 4 litres of MB-1.

--
Johnny B Good