Vailliant using bad Honeywell valves

[Jonathan Schneider]

Happy New Year All.

I bet none of you were lucky enough to spend some of your first morning of 2006 diagnosing your cold Vailliant boilers.

My boiler is a five year old ThermoCompact 142/1 E and when it was just over two the main gas valve failed. It was replaced at a cost to me of around £200 and was then fine for almost two years. I should add it has been me diagnosing it (being electrical problems I am better equipped than the plumber to do). In November 2005 exactly the same thing happened again.

Turns out the newer replacement valve was running burning hot to the touch, now had a too-low resistance, would fail after about ten minutes unless a cold air blower was directed towards hit fixing the symptom rather than the cause. A dodgy procedure I know but the house was cold, I was fed up etc. Also over the last two years the original valve has magically healed itself (some sort of self-resetting thermal fuse ?) and now looked electrically ok like it didn't two years ago. Really.

I naughtily, carefully, but avoiding paying the plumber, put back the original valve mid December and all was fine until this morning.

I now have two Vaillant valves with a different open circuit coil each. (They have two which run in series from rectified mains.) I have also decided that a valve cannot be damaged by a faulty rectifying lead. That is it cannot do worse than apply the 400v DC it does in normal operation. As I had bought a second I was able to determine that a lead has a full wave rectifier in it and that the original lead is fine.

I have also come to the conslusion that it is likely that Vaillant must have come across the problem and that is probably why, as my plumber tells me, they use a different valve on newer boilers.

Legally speaking I believe I have recourse against my plumber for something with an "inherent design fault" in the words of the act though I would rather pursue Vaillant of course.

Jon

[John]

Really? can you tell us why you have this opinion?

You sound like the guy I went to a couple of months ago. His (oil) boiler had gone bang and it transpired from asking his wife that he had decided to find his own fault by putting in ever increasing fuses until the fault became spectacularly visible (groan). The actual problem had started with a small weep from the expansion vessel whch dripped onto the mains lead of the ignition module and blew a 3A fuse. If he had left it alone at that point matters would have been simple to dry it out, but no he had to prove his manliness by finding the fault himself. When he had finished the repeated exposure to fault currents meant boiler needed a new ignition module, new lead, new Satronic sequence control box, a repair (Thanks Geoff) to the PCB where the excess current had blown tracks off the paxolin and a new expansion vessel as the old one had developed a pinhole in the seam. No heat or hot water for a couple of days underlined things and his wife promised he would never be allowed to try to find his own faults again

Get your case put into better order than the way you have described it here or you will be dead in the water with a big legal bill when Vaillants legal eagles set about you if you don't. Going after your plumber will only serve to increase your bill as his legal team will simply involve Vaillant so you end up facing two defenders. As with all these things the only ones to make money will be the solicitors and barristers

[Mike Tomlinson]

In article , Jonathan Schneider writes

I've just had exactly the same problem (just before Christmas) with a Potterton Suprima. The gas valve ran very hot and began to chatter loudly a few minutes after the boiler was turned on, eventually resulting in gas cutoff and the burner going out.

Tried a recon PCB from Geoff which made no difference, so called a Corgi out to look at the valve since I don't mess with gas. On removal, it was clear that the coils had burnt out; the plastic coating on them was melted.

I don't agree. Diodes can check out fine but fail under load. Have you checked the supply to the gas valve when energised with your meter on the AC scale to see if any AC is present?

I measured 215V dc on my Suprima's valve, and an AC component of 100V ac measured using a digital multimeter.

[Peter Parry]

You may have a case against the retailer you bought the boiler from but you would have to prove the fault, or cause of it occurring, was present at the time of sale. At the least this would require an examination and report from someone suitably qualified and you would have to pay for this. After 5 years your chances of succeeding with such a case would be fairly poor.

Vaillant have no responsibility as you have never had a contract with them. You would not be able to take any action against them.

[Jonathan Schneider]

A working lifetime of designing and diagnosing electronic components and systems.

As I said the problem falls well and truly into my domain and I wouldn't be making such accusations if I didn't think I couldn't defend them.

Yes I have of course checked that mains is getting to the valve but as the latter is open circuit it isn't going to help, really.

Jon

[Ed Sirett]

I doubt you are going to get far. Firstly the manufacturers probably have quite good data for failures in the warranty period. Secondly they will have some idea form the flow of spares which parts are troublesome.

IMHO, The better manufacturers do change the specification of the parts in response to systematic stock faults, the worse ones simply bring out a new model with a different set of stock faults.

IANAL but the only way that you could make out that the boiler was not fit for service (with the occasional breakdown) was to show that your boiler had a lot more trouble than could be expected. To get through two gas valves in five years is bad. But if you really want a better boiler then you should have bought something _much_ better.

Let's face it if you had bought a £300 quid boiler then you'd probably have spent twice that in spares by five years.