Oil boiler on lockout after new motor fitted

[Ashtara]

We have beem having intermittent problems with our oil boiler for a few months now where it goes to lockout on start up n morning - doesn't even start to fire up but always starts on first reset.

Engineer said as its first thing and not even firing its the capacitor/motor not working.

This was replaced on Friday and a new nozzle put in at the same time. Since then, each morning it has locked out and had to be reset (this morning took two resets to fire). It is now worse.

As its bank holiday, and can't get anyone round to see it till next week just wondered if anyone had any ideas.

Obviously it is something to do with the motor as that's what was replaced and daily lockouts since but just curious to hear your opinions.

 

[Burnerman]

I think it would be good to know what actually happens when the burner tries to start up from cold on its own......can you hear the sound of the motor spinning up, for example or is there just a buzzing or a humming sound?
Presumably the new motor came with a new capacitor....you may have a sticky fuel pump that takes a while to get up to speed.
John

 

[dcawkwell]

You engineer is a plank.
Get someone else.

 

[Ashtara]

Dont hear anything not even the initial start up just slight buzz then lockout. Yes did come with new capacitor. Engineer has said he will try another motor?

General comments like 'he's a plank' don't help unless you explain your reasons for them

 

[Burnerman]

It may help you to uderstand what happens when an oil burner starts up, and therefore a possible diagnosis.....
The motor starts spinning - its connected to a fan that purges fresh air through the boiler and up the flue. This happens for about 8 sec, and the ignition spark is there at the same time.
Then, a solenoid on top of the oil pump then opens, and allows kero to flow through the nozzle, where it ignites courtesy of the ignition spark.
Once a flame is established, a photocell sees the flame, stops the ignition and keeps the oil flowing. The timing for all of this is courtesy of the control box, with the lockout / reset lamp and button.
So - maybe the new motor or capacitor is faulty...thats pretty unlikely but I'm sure it does happen....you can usually hear whats going on, and you may also hear the ignition spark. Depending on the make of the burner, its possible for the drive coupling between motor and pump to fail, but that too has a characteristic sound.
Its also possible that there is air in the fuel supply line, but I would have thought that would have self bled by now.
So, we (and you!) need to know if the burner actually starts and then stops, or makes no attempt to start in the first place!
John

 

[Ashtara]

Ok so what happens normally is I hear the boiler do its initial sequence start for a few seconds (never counted but would guess around then a little click and then the boiler fires.
On morning lockout I hear nothing at all just a little buzz then lockout. So I don't even hear the initial sequence where the boiler starts before firing.

Hope that makes sense

 

[Burnerman]

In which case I have to say it sounds like a faulty motor or capacitor, or an oil pump that is too stiff to initially turn.
All are easy enough things to test on the bench but if your engineer is returning, maybe thats up to him.....
John

 

[Ashtara]

Thank you burnerman he is fitting new motor so will keep you posted

 

[Boilerman2]

The make and model of the boiler may be of use in helping -
Is this boiler a Worcester Heatslave by any chance?

 

[Ashtara]

Outside wall hanging thermacon 50/80

 

[simond]

In which case I'd be having a good look at the oil pump before putting new motor in.

Would be worth getting your maintenance man to show up on the first start up in the morning.

 

[Ashtara]

Oil pump already been changed in November 2012

 

[simond]

Why was this changed out?

It might have been helpful to have mentioned something relevant like this earlier in the thread?

 

[Ashtara]

Intermittent random lockouts.

Nozzle, photocell, solenoid checked

control box changed feb 2012

Not much left to change

 

[dcawkwell]

Intermittent random lockouts.

Nozzle, photocell, solenoid checked

control box changed feb 2012

Not much left to change

You have air leak in the pipework given it is a wall mounted boiler
unless you have a two pipe system. You will need a tiger loop
or you have a faulty non return valve.