Central Heating Failure!

... one more reason to love those big tube amps.

[QUOTE]Originally posted by naim_nymph:
Last Saturday I awoke to a very cold house.
The central heating was not working, and long-story-short after checking things…

I diagnosed the problem down to a worn out Honeywell 3 port motorised valve [it’s been playing up for a while] so without delay I researched the remedy on the internet where I was happy to find lots of info on DIY by simply changing the motorised head unit which is a fairly easy mechanical/electrical job and doesn’t involve the water side of things nor getting an expensive repair bill from a professional plumber.

The new head unit arrived yesterday, and I’ve spent most of today trying to figure out why things haven’t worked out to plan.

It fitted on okay, the 5 wires were the same colour code and connected okay.
But when I switched the fuse box back on, the pump started up strait away - although it was on the Off position. It would seem to have other irregularities to include turning off on the ‘On’ position, and the head unit won’t stop clicking when changing from water to radiator, or vice versa ~ not sure which way around it’s going acually, and while the pump is going, the boiler is not.

Is the ‘compatible’ for Honeywell head unit faulty, or gone wrong?

My rewire was careful, I snipped the 5 old wires leaving 5cm in place to mark where to put the new wires in, and same colours in same places.

Anyway, I’ve found a basic wiring diagram, and managed to hot-wire it so the radiators get hot and will turn of when hot on the thermostat, so I can leave it on auto, but if I switch the central heating ‘Off’ …the pump starts up again, so it’s still far from working properly.

Should I just get a genuine part and try again?

Or get in a professional? (who will charge me a weeks wages for doing a few hours of work).

Or, perhaps the constantly clicking constipated head unit is because the brass valve is too old and stiff to function properly, so perhaps I need to replace it with a complete 3 port motorised valve and not just the head unit?
That would be a job for a plumber imo, I don’t like to work on central heating pipes.

Any good knowledgeable advice please?

Debs

You pay a plumber for what he knows and not what time it takes!

quote:

Originally posted by steviekoi:
You pay a plumber for what he knows and not what time it takes!

Yeah, some plumbers around here are so knowledgeable they bill you for your life savings.

Although, there is a shortage of good guy plumbers in this area, and i've been unlucky in the past with the cowboy type from Bodge and Scarper Ltd.

Meanwhile my CH system is working on heating the rads + water simultaneously, plus it turns off and on okay on the room stat. So i haven't frozen to death yet.

Trouble is i can't turn the system off [not that i want too right now] ...and i don't know if the cyl stat is active... it's all very odd.
Also i'm sure the brand new replaced "compatible" Head Unit is not functioning correctly [probably due to electrical incompatibility] and i think it probably needs a new brass 3 port valve as well(?)

I've been trying to contact the guy who services my oil-burner, but he's not answering his phone.
Must be a busy time for plumbers.

Debs

Tried it myself a couple of times over the years and ended up having to get in somebody who knows what he's doing. First time in fact it was a friend in the trade and he discovered the original installation (by a pro for the builder, W****y) was botched up and the heating was being controlled by the hot water thermostat. For several years the previous owners had wondered why the heating had to be turned up to its maximum just to heat the house to a reasonable level. They'd assumed it was because it was quite a big house.
So don't just get a pro in, get somebody you trust.

quote:

Originally posted by TomK:
So don't just get a pro in, get somebody you trust.

I couldn’t agree more, that’s why I’m trying to contact the guy who services my oil-burner. Watching him checking, cleaning, and testing out the oil-burner is conclusive to his meticulous attention to detail [he may have been a LP12 sondek engineer in a former life] and his charge rate is very fair too. He also does plumbing work so i’m very keen to get him acquainted with my CH system which is well over-due for a jolly good going over type service, with new belt springs and mat, if you know what I mean.

The problem with living out in the middle of nowhere is most white-van-man plumbers will need to do a 30 long wintery snow-swept mile round trip to get out to where I live and back, and that takes time [and time is money] so it would pay me to use the clever local plumper for local people, when I can get hold of him... perhaps he's on his holidays, sat on the beach in the Bahamas(?)

SNAP - & couldn't agree more re using a professional

I got back last Thursday morning after 4 weeks overseas
The house had been left with the hot water off & the CH @ 15'c & timed to run only between 18:00 & 06:00.
We arrived home, switched the programmer to normal times & temps & got a horrible gurgling air bubble noise.
My quick diagnostic found the Honeywell 2 way diverter valve was stuck half way. It was actually blocked with hard black oxidised ferrous sludge that most all CH suffer with eventually.
- damn it I should have changed it when I had it drained down for DIY last summer.

Anyhow, the time was 7am (ish), we called our boiler/gas/heating/water/sewerage service contract people. They arrived at 8:30 & we had a new valve installed & were warm as toast by 9:30.

--------------------

A side story on Honeywell: When I was working I was on my companies supplier liaison committee, & for my sins I had Honeywell on my responsibility list. Not a company that understands the words cooperation & partnership. Anyhow, they got the order of the boot & we moved to Danfoss - a blast of fresh air & cooperative partnership sunlight if there ever was one
Now I see our beloved MK, they of Logic 13a unswitched sockets & Toughplugs, are part of the same group as Honeywell.
....... must check out Crabtree

Whose make did you replace the head with ???

quote:

Originally posted by deadlifter:
Whose make did you replace the head with ???

At the time of purchase i thought the 'Head unit compatable with Honeywell V4073A' was a new type Honeywell to replace an old type Honeywell... it didn't state it was a patten design, and after delivery the following day, and upon inspection the head unit is unbranded(?) ...but clearly not Honeywell.

But the 5 wires are the same colours though, and it fitted on fairly easy.

But electrically things are not right at all, and going by the clicking noise, the replacement head is not switching the valve over which i think means the old brass work 3 port valve needs replacing too.

I think i should order up a genuine Honeywell 3 port motorised valve (complete) to be ready for when the plumber arrives ?

Debs

Its always best to replace like for like and the new heads come with the valve lever in the locked position so when you remove the old one make sure that one is in the locked position as well [ by that i mean locked in manual position ]. A while back to save money for a friend i fitted a Salus mid position valve in his Y plan system when the original Honeywell gave up the ghost after sterling service over the years, the Honeywell being about £70 and the Salus being about £30 so a lot cheaper which in his eyes won the day but due to that brand being cheap shit i replaced it three times over the next two years due to problems [manufacturers issues] then he said get the Honeywell so i did and have not had to touch it since [ two and a half years ago ] CHEAP IS NEVER CHEAP IN THE LONG RUN

quote:

Originally posted by deadlifter:
CHEAP IS NEVER CHEAP IN THE LONG RUN

My buying decision wasn't based on getting a cheaper one, i really thought it was the genuine Honeywell replacement part at the time i placed the order, but due to ambiguity in the wording, and my unfamiliarity on this subject, i got caught out.

Although, my CH is working again, albeit not properly but it does give me some time to organise the repair with the trusted local man of my choosing.
I'm pretty sure it needs the whole 3 port valve and not just the head unit, and that's not a job i want to try on.

The wiring puzzles me too, the (Sunvic) junction box doesn't look that complicated, and i believe the numbered connecting blocks are subject to a standard arrangement?,

...so i am suspicious of the patent head unit wiring being not as compatible as advertised.

Debs

Debs,
I doubt you got the wiring wrong, and as far as I know they have not changed in 20+ years. Changed mine a couple of times and fitted a few to parents and my old house - they are fairly simple if you are able to DIY with competence (sounds like you can).
The valve can be set manually to be permanently 'open' and hot water goes to heating + hot water at all times the pump is on. This is achieved by the sliding finger lever being pushed open and trapped under its spring pressure behind and above a little 'v' cutout above it when pushed as far as it will go. You cant miss this lever - it is obvious on one side. If the valve is electronically open then there will be no pressure needed to move it.
Wiring plans:-
http://www.diyfaq.org.uk/docs/...ial-Wiring-Rev1c.pdf
under (probably) Y plan. Please check this carefully though! It wont be the 's' plan as that uses two valves. They only used to do two plans back then (S&Y) - there are a few more now!

Easy to check - just be careful!
The entire wiring plan (I'm guessing yours will be the 'Sundial' Y plan, is fairly easy to follow - so you can also check your cyl stat as well.
If, as you say you have not replaced the entire valve then the 'ball head' on the inside could well have broken down / seized and the whole unit needs to be sorted. Thats a bigger job usually meaning a drain down.

quote:

Originally posted by Frank F:

quote:

But the 5 wires are the same colours though, and it fitted on fairly easy.

Should have used NACA5

FF

For a while it was cryogenic treatment all around, but i certainly don't perform any better for it

Few years back our CH pump failed so I sourced a replacement, installed it and.....couldn't get it to turn off!
After some investigation I found that the microswitch on one of the motorised valves was fused and that the system had been wired so that the pump was always on, even when both valves were shut. Explains why the pump failed. Also discovered that the fuse in the consumer unit had blown and been repaired with tin foil. No doubt all this happened when the system was being installed.

The motorised valves were some Spanish make and I couldn't source a replacement for the circuit board. Tracked down a suitable microswitch and replace that on the original board. The wiring for the whole system (it's got separate valves for the CH and hot water circuits) was in a length of connector strip shoved into a box. No labeling at all. Had to reverse engineer all that, including the feeds from the controller (just because it's black doesn't mean it's not live!) and reconnect the valve wiring correctly (for fully operational valves).

Much relieved when it all worked!

Willy.

I have a 1947 apartment in LA, I have a big gas heater with grill. On cold days and nights I"m up and down turning the key for on and off and have a fan blowing to distribute the heat. After many years I bought a small oil heater for my bedroom. Soooo nice.

I had Gas man out for stove and wall heater, he siad I could get a new one but major change in size so plaster would have to be done. Then said they don't make them as sturdy these days, very thin metal and nothing wrong with what I had. I'm not going to 21st C technology, but might get a small oil heater for living room near my spot on the couch. I have multiple throws to drape myself with as I watch TV or music playing.

Now I know why those old people in B&W movies sat near a fireplace and knitted with stocking caps and shawls.