Intermittent starting problem on Mectron 3BM oil burner

[Coastie]

Hope someone can help! I have an oil powered Mistral boiler which has a Mectron 3BM burner. On Christmas Eve (of course) it started to play up, going into lock-out mode. Re-setting has has mixed results, occasionally firing up but often going through the start up cycle - but the motor/air pump is not starting, and it returns to lock-out. When it starts is works for 30-90 minutes, stops (presumably because of the boiler thermostat) and then doesn't restart returning to lock-out.

My guess is that the capacitor might need replacing but otherwise I'm running out of ideas. Has anyone any advice?

 

[oilman]

.................... Has anyone any advice?

Change the capacitor, otherwise measure it.

 

[wilhelm]

well it could be capacitor. but wot you need to do is split pump and motor. and see if pump shaft is stiffish ( oooer missus time folks) to turn. or fire up , and see what motor is like without pump connected... or get someone in.

whilst at it you can examine the drive dog....which may be forked.

i dont change capacitors anymore. its motor and capacitor. and if i have doubts about pump .i change that as well.

buy shares in riello!

 

[kevplumb]

and don't let the herb near the tank

 

[oilman]

.............
i dont change capacitors anymore. its motor and capacitor.

Well I suppose if you have a load of whinging customers who have something done and then bleat that your work on the boiler has wrecked their eletric lawnmower, then you have to just to be safe. Or it could be why people see boiler servicing as a rip off exercise.

and if i have doubts about pump .i change that as well.

buy shares in riello!

Oh, that's it then,......... it IS a rip off exercise.

Better change the control box and the photocell while you're at it, sod it, it's a new boiler needed, change the rads and hot water tank too...........

 

[wilhelm]

have no fear, i do have a conscience.
trust me.

i'll get you, kevplumb

 

[oilman]

......
trust me.

..............

Isn't that a euphemism for "f*** off"?

 

[wilhelm]

and its only the second day into the new year.........

 

[oilman]

.....

 

[silklink]

I thought I was looking at my write-up when I googled this problem. Even down to the same Christmas Eve. Wow.

Anyway, I had an engineer come round and replace the pump. As he suggested, they wear out and become difficult to turn.

All was well after he fitted it, until the first cold snap of this year, which was quite early in November. Same problem.

This time I am thinking that the pump has already been replaced and they shouldn't fail within a year.

I am thinking along the lines of a mixture of the motor and a heat related problem. The boiler has run throughout the summer months with no problem. In fact, I went away for a night and turned the rads thermostat off. WHen I cam back, the boiler was fine just heating the water alone - like in the summer.

It seems that with the colder weather, the boiler works harder and could be creating too much heat for the burner motor axle assemblies. Perhaps the motor is a bit warn and, on stopping at certain points of the rotation, it might be too difficult to start up again.

Would appreciate some expert advice on this because I don't know whether to change parts or go all out for a new boiler - mine is quite old now.