Baxi Bermuda back boiler, late 90's vintage - solenoid problem?

[Tim Southerwood]

Hi,

In the process of clearing a house (deceased relative) and decided the boiler should have a routine service as it'll be running unattended to keep some background heat whilst the building is vacant, and winter approacheth.

Long story short - did the "right thing"[1] and booked in a CORGI fitter.

After he cleaned the boiler, he wanted to fire it up to do the smoke test. Problem is that it wouldn't fire the main burner. After some messing about, I proved for him that there was in fact 240V reaching the solenoid gas valve module

The pilot was on and holding in at this stage.

The control gear design is simple - switched-live from heating controller/stats come in. That goes via a mechanical boiler stat. That then presents to the solenoid valve module that also takes in the pilot light thermocouple and provides controlled gas feeds to the main burner and the pilot. Old style system, no visible electronics (maybe a bit hidden in the valve module, or not).

When I carefully removed the live connection from the valve module and replaced it there was a definite "clunk" coming from the unit which I took to be a valve solenoid.

Weird thing was that the main burner failed to start as a result of the "clunk". Weirder still was that after about 2 minutes, the burner did eventually light up and ran correctly on full flame. Upon turning the boiler circuit off, it took about 1 minute before the main burner shut down. This time lag for starting and stopping appeared to be consistent and repeatable.

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Question: is this time delay between electrical power applied and gas being switched on a feature of some types of valve module? Or is it indicative that the module is on the way out? Sticky bits betwixt the solenoid and the valve perhaps?

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Before anyone asks, I did ask the fitter and he said he didn't know due to lack of experience with that type of boiler. Which seems odd as it's not exactly an old or uncommon model.

Many thanks for any opinions on the valve (or otherwise!)

Cheers

Tim

[1] Nice enough bloke, shame about apparent lack of experience and ability to undertake basic electrical fault finding, considering his hourly rate. I'll do the sodding job myself next time.

[jaxmar]

Hi Tim If as you say your boiler is a late 90's model then is is most likely a Bermuda 552 or 401 model, these models are fitted with the Honeywell multi functional gas control valve V4600C with a grey round push button) which includes the solenoid valve. Once power is provided to the solenoid the burner should light within a few seconds ramping up to the max burner setting within a short time after ignition. The solenoid oporator on these models can be purchased seperatly and is connected to the valve by 4 screws, but your problem may not be the solenoid at all as the rubber diaphram in the valve may have become brittle and therfor slow in allowing the gas to flow to the burner. I would suggest that you have the complete valve replaced as they are available at much the same cost as the solenoid operater alone. This is not a DIY job as it involves gas connections being taken apart and also it is unlikely that you have a manometer to set the burner pressure after fitting a new part. Hope this is useful Martin (CORGI reg gas engineer)

[Tim Southerwood]

[e-mail] coughed up some electrons that declared:

Hi Martin,

Thanks for the excellent explanation. Yes, the V4600C looks like the part, after I googled for it. 60-80 quid, not bad.

OK, if this is not normal behaviour, then I guess I should get a replacement scheduled.

Should I consider it dangerous in its present condition, that is, might the diaphram fail and piss gas everywhere, or are these things generally failsafe?

I'm surprised the fitter I had didn't know any of this (I did ask) - he seemed not very experienced, but that's another issue and I'm taking that up with his employer...

Many thanks for your time,

Cheers

Tim

[Tim Southerwood]

Tim Southerwood coughed up some electrons that declared:

I have decided to shut the main gas off when I'm not there just in case, until I have more information.

Cheers

Tim

[Ed Sirett]

Yes it's dangerous but not for the reason you state. That the gas is not (fully) controlled is the issue.

This does seem surprising since controls such as these are a part of the core syllabus of training for registered fitters.

[Tim Southerwood]

Ed Sirett coughed up some electrons that declared:

Which I guess may potentially lead to the same outcome, say if the pilot light blew out, then the main burner was fed via the faulty valve. Ouch, now I'm scared. The gas goes off as soon as I get down there today.

I'm generally surprised. I'm a layman WRT gas, but:

When the fitter couldn't get the burner to fire, there was much head scratching and wondering if the controller was supplying any power to the boiler.

I suggested it should be as the controller was on, (manual call for heat and neons lit up), and both the tank and hall thermostats were set to max. Heating had been working days prior.

He then wondered aloud about the boiler thermostat. After about 10 minutes of fiddling, I got bored with waiting for him to do what seemed obvious, ie. go and get his multimeter and start testing. So I broke my policy of non interference with professionals-at-work and went and got mine and offered assistance, which was happily received.

Didn't take me long to prove to him that there was power to the boiler. I then proved the boiler stat was working correctly then prove power to the valve. It's not a complicated valve, 2 terminals L+N.

Despite this, every now and then he kept wondering if it was the programmer or wiring or something else. I politely pointed out that if the valve was powered, but not operating, then it was reasonable to deduce that the valve may have a problem.

Ed: could you comment on one other thing, if you wouldn't mind, from a CORGI POV:

First thing he asked for was the boiler instructions, which I found (this isn't my house, so I was lucky there).

Unfortunately, the instructions for the fire were not included and I couldn't find them.

He said he didn't know where to place the smoke match on that fire, so he didn't appear to manage to complete a smoke test (the one effort he tried had smoke coming back out into the room). I should add that his smoke test of the main burner had clearly proven to me that the chimney was fine.

No one had previously asked me to ensure instructions were available, but the company receptionist did say after the job, to me, that I should have had the instructions available and it was a CORGI requirement. Is that true or false? Would you expect a CORGI registered person to need instructions to conduct a smoke test on a gas fire?

Skipping to the end, I rang up the company after he left, who I have had excellent results with on two previous occasions, and disputed the time I was charged as it seemed to me that this chap was wasting a lot of time through lack of experience.

I'm now wondering, if he issued a landlord's cert (I paid for one, as I thought it might be useful when selling the house) and the cert states the installation is safe, but there is in fact a valve in a dangerous condition, then I should raise this, first with the company, then with CORGI.

How would you recommend I proceed? I initially reckoned that I've been charged for time spent faffing, but I'm now thinking worse...

On a minor point, is it acceptable to perform leak tests with a mug of customer supplied Fairy liquid+water? I thought they used specialist liquids like Leek-Seek or similar? That's a minor point, but I'm trying to form a picture here.

Cheers,

Tim

[Tim Southerwood]

[e-mail] coughed up some electrons that declared:

Hi Martin,

Just come back from the house. Turns out it's a 57/4M, but the valve is still a V4600C AFAICS from google. Possibly because the installation date was actually around 2000 or 2001 - I found some documentary evidence suggesting this. Fitted with a VP3 fire front.

Upon further investigation, the valve is most definitely shot. Here's what I did:

1) Turn on system, light pilot. 2) Engage heating demand. 3) Wait. And wait... 2 mins later or so: 4) Burner starts to fire up. But in a very half-arsed way. Over the course of the next minute, I can actually hear the flame becoming stronger until it reached normal levels. This seems to concur with your suggestion that the diaphragm is hardened. 5) After a while, go out, come back in. Smell gas. A localised cloud from the fire to about 4 feet away. Not very strong, but unmistakable. 6) Shut down gas at meter, of course. And isolate boiler electrically.

I suspect that the valve is opening so slowly, that a certain amount of gas escaped before the burner flow comes up to a level that it wants to ignite. That's the only theory I have. Anyway, I'm now very p*ssed off with the fitter, so I propose to stop the cheque and get one of the firm's more senior engineers down on site to have a look. As to whether I give them a bollocking or take it to CORGI I haven't yet decided (open to suggestions).

I've lost patience because I, as a layman, specifically queried the state of the valve. It's not like it was an understandable oversight. So I have a landlord's cert on a potentially unsafe installation - should get interesting...

Cheers

Tim

[Ed Sirett]

The guy may have never met a back boiler before if he was fairly young. However identification of the function of these types of control is in the core syllabus.

Somehow he is not up to the job.

Did he have a CORGI card? Or was he simply working for a registered firm who were passing him off as a registered fitter whilst he was in fact unqualified? This is not unknown.

Far be it from me to drop the company in the doo-doo but I can entirely sympathise that you have a grievance.

It is said that you can almost get an MOT for a car without an engine. It is similar that you could get exam passes in gas fitting whilst having almost no diagnostic skills. However knowing how a multifunction valve works is in the core syllabus, leaving it in a dangerous state breaches a stack of regs.

Even if I did not have the labels/forms to hand to condemn the boiler I would at least have unscrewed the t/couple and/or disconnected the mains connector and/or removed the fuse from the supply, aswell as informing you not to use the boiler.

[Tim Southerwood]

Ed Sirett coughed up some electrons that declared:

Hi Ed,

Thanks for the reply.

More in the mid 30's. Quite possibly he's just gone into the gas profession from something else.

Cardinal sin - I don't know. I'd used the firm (local family business) twice before and had excellent engineers/fitters so I didn't ask. The firm say he is registered though.

I don't like dumping folk in the cr*p, but I have to consider: what if I were little old granny Smith and didn't question the chap's ability? If I'm right, he needs picking up. If I'm wrong, I'm prepared to eat my hat.

I had the fitter on the phone asking me not to get CORGI involved. Had the office manager on the phone too, chewing my ear off for daring to question the competence of her staff.

If she had had taken the line that I'd made a serious allegation and could one of their more experienced staff come out and have a look, I might have let the firm deal with it. Once people start trying to bully me into submission, I tend to become more suspicious. As it happened, between them, they convinced me that I should get CORGI involved. My final take is that if they did things right, they shouldn't have anything to worry about from an inspection.

I know the place - it was in Surrey, in the early 90's. MOT in 15 minutes, engine still cold, car unmoved. Long since closed down...

I wish he had. The house is unoccupied and it's just supplying background heat to avoid damp problems. I would have been the most co-operative customer in the world if he's asked me to shut it down.

As it happens, after the couple of phone calls above, I did phone CORGI. I explained the problem, and they decided to put me through to a technical department.

I explained the situation again and asked them if I was over-reacting. The opinion from them was as here, that the valve was clearly exhibiting non-normal behaviour, that the fitter should have performed more tests as I'd mentioned the possibility of having smelt gas, and yes, I should file a complaint.

Nothing to do now but wait.

Cheers

Tim

[Heliotrope Smith]

and wait..... and wait.....

and w........

and .........

......

[Tim Southerwood]

Heliotrope Smith coughed up some electrons that declared:

Heh. I hope not. CORGI claim 10 days. Hope they meant earth-days.