Grant oil boiler woes!

[dobbslc]

Help!
My boiler wasn't working this morning so the house was stone cold along with the hot water. Missus is not happy!
It keeps trying to fire up as I can hear the ignition but after about 5 seconds it shuts off again, it just repeats this over and over.
I've checked a few things like oil supply etc. Could it be the flame sensor not detecting heat or even a frozen condensate pipe?
Any tips welcome.

 

[Blobber]

With the cold weather I would guess frozen condensate, does it show any fault codes?

 

[cocker]

Ours does something similar if the pump gets air in it .

 

[Migmac]

We had similar with our Grant combi boiler. It was our timer clock that was at fault. It got removed

 

[MattF]

Missus is not happy!

Bet the dodgy boiler ain't helping either?

 

[Matrixx]

if its an oil burner it sounds like the flame sensor not detecting the flame, it may need cleaning or replacing.

 

[dobbslc]

With the cold weather I would guess frozen condensate, does it show any fault codes?

It doesn't have any fault codes only a light on the pump which seems to be working.

Ours does something similar if the pump gets air in it .

I've blead the pump and taken out the oil filter as it looked filthy, there's plenty of oil flowing! I don't think it was the filter. No sign of water or ice.

We had similar with our Grant combi boiler. It was our timer clock that was at fault. It got removed

It's the boiler at fault as it's trying to work so has the call for heat.

 

[dobbslc]

if its an oil burner it sounds like the flame sensor not detecting the flame, it may need cleaning or replacing.

It's a Riello RDB burner. I've had the flame sensor out and cleaned it but it was dirty anyway.
I'm about to test the pump motor is getting voltage.

 

[hotponyshoes]

You should be able to hear/feel the pump running?

On mine there was a sticking solonide on the oil pump.
Couldn't get decent access to it but slapping it a few times with a soup spoon worked.

 

[MattF]

slapping it a few times with a soup spoon worked.

 

[Migmac]

It doesn't have any fault codes only a light on the pump which seems to be working.

I've blead the pump and taken out the oil filter as it looked filthy, there's plenty of oil flowing! I don't think it was the filter. No sign of water or ice.

It's the boiler at fault as it's trying to work so has the call for heat.

Ours fired,stopped,fired, stopped would have done it all day long if you left it switched on

 

[dobbslc]

Love the soup spoon technique

if its an oil burner it sounds like the flame sensor not detecting the flame, it may need cleaning or replacing.

Right I've got the photocell / flame sensor out and tested it and it's open circuit. I've watched a utube vid and it should have a resistance of about 600ohms so now to track a new one down.

 

[dobbslc]

I've just tested it again and I'm not getting 2 meg ohms then nothing then a different reading so I think it's definitely screwed. City plumbing say they have one in stock

 

[Fintray]

An easy way of testing the photocell is to pull it out of the burner and shine a torch at it and switch on the burner, if the burner starts then stops the photocell is faulty.

 

[Fintray]

It doesn't have any fault codes only a light on the pump which seems to be working.

The light you are seeing is the burner tripped light, it is not on normally.

 

[awemawson]

On one of my three Grant oil boilers recently, it would start up then pretty imediately stop. It was the motor capacitor dead.

 

[julianf]

An easy way of testing the photocell is to pull it out of the burner and shine a torch at it and switch on the burner, if the burner starts then stops the photocell is faulty.

If you shine a light on the photosensor before the electrodes start firing, they never will fire.

Its, so far as I'm aware, some safety thing - if the sensor sees light it thinks there's a burn on the go anyway, so just tries to purge it with air, and never energises the fuel solenoid.

You need to keep it dark, and then give it light once you hear the electrodes.

Edit - this is for the riello burners. Old ones are more basic.

 

[Kayos]

If you shine a light on the photosensor before the electrodes start firing, they never will fire.

Its, so far as I'm aware, some safety thing - if the sensor sees light it thinks there's a burn on the go anyway, so just tries to purge it with air, and never energises the fuel solenoid.

You need to keep it dark, and then give it light once you hear the electrodes.

Edit - this is for the riello burners. Old ones are more basic.

Self test, light before it fires means a faulty sensor so it doesn't try

 

[Fintray]

If you shine a light on the photosensor before the electrodes start firing, they never will fire.

Its, so far as I'm aware, some safety thing - if the sensor sees light it thinks there's a burn on the go anyway, so just tries to purge it with air, and never energises the fuel solenoid.

You need to keep it dark, and then give it light once you hear the electrodes.

Edit - this is for the riello burners. Old ones are more basic.

Sorry, you are correct, light after you hear the sparking.

 

[jenki]

Not sure if this will help Dobbslc, there is a small plastic drive coupling between the motor and the oil pump that failed on mine (Reillo RDB) replaced and has been fine since as with awemawson I have had a couple of capacitors.
As an aside I was surprised how stiff the oil pump was to turn by hand.