viessmann 100 boiler keeps switching off after 30 mins

[lmhud]

Ok I went to the 3 port valve and tapped the metal part a few times with a toffee hammer and the boiler has sprung into life, its been working for 5 hours now without going off

Does that mean the top part of the valve needs changing or the whole unit

Thanks

 

[JohnD]

I'd start by checking all the connections are sound.

It is more likely the head at fault, if you take it off the base you should find it operates the spindle mechanism freely (it only moves about a third of a turn IIRC) and you can try operating the valve by hand to see it turns to and fro OK.

Was it a new one when the boiler was fitted? They usually last many years if a good brand like Honeywell or ACL. Look for any sign water has leaked and got into the head.

You can get a wiring diagram off the makers website that will tell you what colour are the "confirmed moved" wires. I used to know but have only ever fitted one. I have an idea the 28mm valve has one more wire than the 22mm valve, but am no expert.

 

[lmhud]

Boiler and the valve were both fitted 11 months ago.

I know you can buy a new one that just happens to be dodgy, I bought a car like that once.

It is a Sunvic, I believe there not very good but it replaced a sunvic which lasted over 9 years and was still working when we changed it for this one, just thought it was the sensible thing to do hmm maybe it wasnt

 

[Agile]

Take head off and see if spindle moves under finger pressure.

If so then if fault persists then needs new head.

Tony

 

[universal]

I don't advise calling any one from the Viessmanns list. This list contains any one that has attended a one day course and includes a lot of numpties. If the Viessmann engineer that attended was even a little helpful he would have identified the fault for you. This is common for company men to provide as little help as possible. It sounds like your on the correct trail with the motorized valve. Im a bit puzzled about the 30 mins though. Can you use a multi meter?

 

[holty]

If the Viessmann engineer that attended was even a little helpful he would have identified the fault for you

why? i get called out to resume a problem with the boiler not the installation. last problem i had, was with the boilers fuse blowing. and was down to the sparky not being able to wire up a heating system properly. so would you expect bmw to sort out a problem when a driver wrongly puts petrol in a diesel car. i dont think so.

 

[Agile]

This list contains any one that has attended a one day course and includes a lot of numpties.

I am on that list too!

But I have been on four days of courses there!

Tony

 

[Gasman77]

I don't advise calling any one from the Viessmanns list. This list contains any one that has attended a one day course and includes a lot of numpties. If the Viessmann engineer that attended was even a little helpful he would have identified the fault for you. This is common for company men to provide as little help as possible. It sounds like your on the correct trail with the motorized valve. Im a bit puzzled about the 30 mins though. Can you use a multi meter?

Wind your neck in fella - as you are totally clueless about this industry works, a manufacturers engineer is only payed to work on the boiler - he starts fecking around with customers controls and breaks one, who will pay for it? his company won't. Be careful who you are calling numpties, alot of guys on here are approved installers for various companies