Solved! Thanks! Old Oiler boiler not firing

[Hollie Bedford]

Hi There,
My (very old) oil boiler has decided to not fire up today!
Only thing I did yesterday that was any different was I turned down the stat on boiler to continue running the pump without heating up the water anymore as I was bleeding and trying to balance the system (trying because half the lockshields are gummed up and one leaked when trying to mostly close that rad off!)

Turned thermostat back up before trying to put the heating on this morning and the oil burner won’t fire up. Also the manual starter button which I am pretty sure normally lights up is dark.

Have tested the positive and neutral posts on burner and is not receiving any voltage.

I am thinking this may be a broken thermostat as seems an unlikely coincidence that this would happen just after I have adjusted it. but would this cause no power to the burner?

Any help appreciated!

Happy to switch the thermostat out for a new one but not certain of the part I need.

Found this one at screwfix looks the same but not certain if it is correct for this application.

https://www.screwfix.com/p/strom-ss...MIq_OdvtCt5gIVjLTtCh2nUQJOEAQYASABEgJDzvD_BwE

 

[Terrywookfit]

That is not a compatible stat.
What are you measuring voltages with?
Have you tried pressing the black button on the stat.....Make sure any timers and stats are calling for heat.
Check for mains voltage between the brown and blue wire as photo 3.

A photo inside the thermostat is needed for further instructions.

 

[Burnerman]

As the lock out light on the burner itself isn't lit, then the fault is very likely to be the thermostat.
Apologies, I can't advise on the replacement 'stat, but others will know.
John

 

[Hollie Bedford]

That is not a compatible stat.
What are you measuring voltages with?
Have you tried pressing the black button on the stat.....Make sure any timers and stats are calling for heat.
Check for mains voltage between the brown and blue wire as photo 3.

A photo inside the thermostat is needed for further instructions.

Thanks yes I am checking for voltage at brown/blue wires in photo 3 with a multimeter set on AC voltage.

Will upload a clear photo of inside of stat after work today as didn’t take one this morning.

 

[Terrywookfit]

Thanks yes I am checking for voltage at brown/blue wires in photo 3 with a multimeter set on AC voltage.

Will upload a clear photo of inside of stat after work today as didn’t take one this morning.

The burner posts are blue and orange..( To my eyes ).
Check from blue to the brown wire that comes out of the flex and joins in the loose connector.
The brown will go up to the control and limit stat and return on the orange connected to the burner.

 

[Hollie Bedford]

Thanks to everyone who has replied, turns out it was the reset button on thermostat was not pressing fully, took off cover and pressed the inner switch and it fired up first time!