SD Thelia 23 problem: Pilot light does not stay on

[wizy77]

Hi there,

I have a Saunier Duval Thelia 23. It was working fine until I turned off the mains power this weekend to change a fuse elsewhere. After I turned the power on I realised the pilot light had gone off.

I tried to turn on the pilot light by pressing and holding the black switch. I can see the pilot light coming on after a few seconds. When I let go of the switch, the pilot light goes off as well. This happens even if I hold on to the black switch for more than a minute.

Can someone suggest what may be wrong? Would it be the 'pilot thermo couple' or the switch itself?

Any help will be greatly appreciated

Thanks

 

[gasgeezer]

hi could be thermo-couple or could be interrupptor connected to o/heat stat. to check get a multi-meter and set to mva put one probe on thermo-couple other probe on o/heat stat lug s/be about 10-12 mva. repeat on other terminal of o/heat stat reading s/be equal if not replace o/heat stat.. if thermo-couple the replacement will be different to original, pilot went out because power switched off fan needs to be running to oxy-genate pilot flame