oil boiler shutting down after a few mins

johney

hello folks,
fuel good, stat not triggered as water not hot enough and pump working fine.
Lock's out after a few mins and when button pressed motor will not even switch on. Must be left to cool fully before working again. Power to unit OK but some electrical fault inside.
What can cause this? Photocell or coil?
Thanks

exaisle

Have you run out of oil? Check that it's actually getting fuel and that there isn't an airlock or something blocking the filter.

If you haven't run out of oil, does it actually light when it starts or does it just make a noise?

There's a timer in the circuitry that won't allow you to switch it back on immediately....

The jet may be blocked....or the photocell may be covered in soot....

punisher5112

Has it been serviced recently and yes most likely dirty and needs looking over.

agusta

These symptoms would say it is not the coil or photocell.the motor should run and start anyway.
Turn down the boiler stat to minimum,when the burner stops turn up the boiler stat and see what you get...,you may have an air lock or low pressure in the system

agusta

johney wrote: »

hello folks,
fuel good, stat not triggered as water not hot enough and pump working fine.
Lock's out after a few mins and when button pressed motor will not even switch on. Must be left to cool fully before working again. Power to unit OK but some electrical fault inside.
What can cause this? Photocell or coil?
Thanks

Does the lock out light come on when burner stops?
When the boiler cools fully does the burner restart itself or do you have to manually press the reset button?

johney

thanks lads.

Did everything with the stat already to no avail.
lockout light not working. but boiler does not come on, even when cool. Up to now we have just switched it off. Then later we would switch it on again and it would start as normal for around 10 mins then cut out. When pressing the button absolutely nothing happens, no motor, no clicking, nada.

jimf

your stat could be gone arseways

can you check if you have power to the stat and out to boiler ideally you need a multi meter

JamesM

It looks to me as if the boiler is reaching a temperature, maybe not the correct temperature, and shutting off until it cools. Check the temp of the flow, really close to where it leaves the top of the boiler. If it is very hot, then you may have a circulating problem. If it is cool, then there may be a thermostat problem. An expert would probably spot what is wrong fairly quickly.
Jim.

TPM

it sounds like the boiler is heating up, switching the stat, turning off the burner but the pump is not running so the boiler isnt cooling the boiler down for the burner to cut back in.
or there is air at the top of the boiler
and now it has tripped the high limit stat(little button beside the stat knob)

you say pump is good how do you know?
is it a grant vortex by any chance

johney

Iv checked the pump. "or there is air at the top of the boiler"
How would you check for and get air out of the top of the boiler?

agusta

johney wrote: »

Iv checked the pump. "or there is air at the top of the boiler"
How would you check for and get air out of the top of the boiler?

You dont check for air in the boiler unless you can fully diagnose why the burner is not running first
a/How did you test the pump,is the pump still running when the burner stops after a few minutes? [if the pump is running, is the pump dispersing heat from the flow pipe on top of the boiler when the burner is not working]
b/ when the burner stops after a few minutes,do you get 220volts between the live and neutral on the burner.

TPM

johney wrote: »

Iv checked the pump/quote]

How have you checked it?
It can be running and not actually pumping.

Can you clarify when you say it won't come on until late it cools down is the boiler getting hot,
And when it isn't cutting in if you press the red reset button/light does the burner try to start or does it do nothing at all