advice pls...burner will not ignite

[shiraz]

Hi,

I have quite an old central heating system and the burner will not ignite. The model is fuelsaver 12RS from ca. 1981. I have checked the electrics following troubleshoot manual and it seems ok. Voltage across solenoid is 25V and when the thermostat is switched off this shows 0. The pilot light is on. Does anyone have any clues please?

Many thanks

 

[twgas]

turn electricity off, disconnect wires from gas valve and measure resistance across terminals.

 

[ChrisR]

Sounds like the gas valve.
Does the gas valve have a blue or brown plastic knob? If so, it's obsolete and you're looking at a new boiler.
Green or grey and you can get it replaced.

 

[shiraz]

thanks Mick

there is a gas control knob, though I am not too sure where the gas valve wires a relocated. can you assist pls?

thanks

 

[shiraz]

Hi Chris

I am unsure were to locate the gas valve. There is a unitrol gas valve and a knob with pilot ignition star and small logo with flame. The knob is turned to this last position once the pilot is on. What are your thoughts?

 

[shiraz]

Hi

I have measured the resistance on the two prongs that come out of the gas valve and it shows 40 on the x1K scale. presume it is 40,000 ohms??

any clues

thanks

 

[tonybhoy]

Pilot on,power at the gas valve solinoid and no burner lit means gas valve/solinoid US mate

 

[namsag]

Usually Robertshaw gas valve on these if avialable it is very expensive, solenoid was avialable seperatly. can be fixed with super glue but not by a diyer not strictly legal but lasts for up to 15 years.
If it was fitted 81 it was old stock as at time they had been replaced with feulsaverS 30 or 40B

 

[shiraz]

is it difficult to repair the solenoid or does it mean the gas valve has to be removed? thanks

 

[NEALDEAN]

im going to ask a stupid question .............

have you turned the gas valve knob from pilot to full flame ?

may sound daft but people do it

 

[shiraz]

im going to ask a stupid question .............

have you turned the gas valve knob from pilot to full flame ?

may sound daft but people do it

yes...any clues no how to check/repair solenoid?

thanks