HRM Wallstar Oil Boiler - Advice please

[Simonvr46]

I cant remember the correct torque setting, I'm sure I saw it on a danfoss bfp pump YouTube video.
The drive key should be solid in its groove with no play, if there was it could cause your issue and eventually shear completely and you would have no pressure or ignition. A photo would of been nice but I'm not suggesting open up again. A dodgy pump coupling could also cause the same.

The burner could draw in flue gases if the flue seals had failed or burner flange gasket was faulty, or anywhere else that could allow products of combustion to escape inside the casing. You could detect these products with a FGA yes.

Just out of curiosity have you ever dipped the tank for traces of water with detection paste? I'm sure this isn't the problem due to what I've seen but thought I'd ask.

With regards to the quote for changing the pump I'm not so sure if that will help now based on what you've said today but without seeing the gear set, drive key or coupling I cant say for sure.

Your correct about the YouTube video, 5Nm for external Allen screws and 3Nm for the 3 internal screws.

 

[SJB060685]

Your correct about the YouTube video, 5Nm for external Allen screws and 3Nm for the 3 internal screws.

There you go, I knew I had seen it somewhere

 

[Simonvr46]

New heating engineer came and replaced the pump, after speaking to Danfoss they recommended fitting BFP21L3 instead of the BFP11L3, heating engineer set pump pressure at 120psi and used FGA to set burner up. All running spot on.
Next morning burner locked out.
Heating engineer been back and resealed all the joints in pipe work with oil seal.
Burner still locking out, but starting after reset.

This evening boiler won’t start.....

Could it be electrodes??

 

[SJB060685]

Remind me again what parts have been replaced?

 

[Simonvr46]

Remind me again what parts have been replaced?

Transformer, pump, capacitor, nrv/firevalve, photocell, solenoid and the control box (7years ago its now a dko).

 

[SJB060685]

Christ that's virtually everything. Yes if the electrode gap is wrong or dirty electrodes it could fail to ignite. If it was arching elsewhere other than at electrode ends then the photocell will usually detect false light and not even open the solenoid for ignition and go straight to lockout. Has this been checked? When the pump was replaced was the coupling checked and/or replaced? You could still be experiencing an excess of air at times if seals were perished as we've discussed before. I have a feeling you might have more than one issue still but of course I could be wrong.

 

[Simonvr46]

Christ that's virtually everything. Yes if the electrode gap is wrong or dirty electrodes it could fail to ignite. If it was arching elsewhere other than at electrode ends then the photocell will usually detect false light and not even open the solenoid for ignition and go straight to lockout. Has this been checked? When the pump was replaced was the coupling checked and/or replaced? You could still be experiencing an excess of air at times if seals were perished as we've discussed before. I have a feeling you might have more than one issue still but of course I could be wrong.

Yeah not much left to replace, the coupling was replaced with new pump.
New engineer says that the excess air amount that’s registering on FGA is ok.
He looked at electrodes when he had burner apart and said they look ok, couldn’t see any sign of arcing other than where should be.

 

[SJB060685]

Has he checked thoroughly though rather than just saying it looks ok? Someone I know had this recently where it was only intermittently arching elsewhere. You got fuel, you got new pump and coupling I know what I'd be looking at next.

 

[Simonvr46]

Im going to speak to him tomorrow, see what he suggests and I’ll enquire about the electrodes.

 

[SJB060685]

When it doesn't start at all do you hear the solenoid click?