Myson Boiler - Pilot light goes out

[helsen]

Hi

I have a Myson Economist WM 15/30 BFa Boiler - Just recently when I turn the central heating off, after a few minutes the pilot light goes out. This only happens when i turn the heating of. I am able to re-light it afterwards. Any ideas as to why this happens would be very much appreciated.

 

[gasmarkone]

Hi helsen. Is it cold already up there in Leeds? This doesn't seem to be an obvious problem to diagnose from here. How do you turn off the system, via the timer or main isolation switch? If the latter it could be tripping the pilot because of no pump overrun. Thats my first guess, but try some more clues and see where it leads!

 

[helsen]

Hi Mark - thanks for that, thought i'd check my heating was working ok for the coming cold months as I had a problem last year with it -several call outs later, I finally had a thermocouple thingy fitted which worked...until now, with this problem. It is the isolation switch so I will see if it does the same thing with the timer - Cheers again

 

[ChrisR]

There's your answer then. If you use the isolator, the pump can't run on after the boiler has finished burning to dissipate extra heat. It overheats, and cuts the pilot off.
The timer turns off the burner but allows the boiler to cut the pump off after it has cooled.

 

[helsen]

Nice one, thanks very much Chris

 

[helsen]

Hi again

I tried both turning of at switch and using the timer and unfortunately both cause the pilot light goes out afterwards ???

 

[doitall]

When you run the heeating and you switch it off, can you hear/feel if the pump is still running.

What happens in the hot water only mode.