Ian Scott asked ... Remove cover off gas boiler?    |    wendy asked ... Old Creda Solar Plus Cooker will not come on?    |    Nick asked ... Oven spark Continuing after lit?    |    Andrew asked ... Jcb cordless 20v combi drill?    |    marc asked ... La machine 1 type 813?    |    Click here to ask your question

Vaillant boiler safety switch pops out after about an hour?

I have vaillant boiler model VCW-sine 18 T3w FD H.

problem: after running for about one hour it cuts off and safety switch pops out, pilot flame is still on but when domestic water or heating is turned on it will not fire.

I can get it going again by pressing the safety switch, it will work for short time and cut out again.

Can you please help with advice on possible things that can be wrong with it and any checks that can be made.

It was serviced about 7 months ago by a corgy person.

many thanks in advance.
surj, October 2007
I sorted mine by changibnf the back electronics board. it is working fine since

surj, November 2007
Hi unfortunately I do not have an answer, but I have EXACTLY the same problem., I have had at least 10 visits by an engineer who has replaced numerous parts but it still keeps happening. Sometimes it can go for a week working fine then it can pop out numerous times in 1 day.
Have you noticed a pattern with your switch popping out? Mines seems to be when the heating comes on rather than the water that may just be coincidence.
The company (who I'll not name) to which I'm paying a £17 p/month fee, are now starting to suggest that I may need a power flush because 'they have replaced most the parts' so it could be because my water in the system isn't clean?
Don't know if this is true or not but I'm reluctant to shell out a few hundred punds on a flush when I'm paying them £17 on a monthly contract which means they should be fixing any problems with my boiler. If they said it was DEFINITELY the water causing the problem then I'd do it, but I'm not convinced considering almost 10 visits later and it's still not working!

Belg, November 2007
link Click here to see other fixes for Vaillant.