Oil-fired Worcester Danesmoor 15-19 Boiler

Dec 16, 2005 14 Replies

I have an intermittent fault on an oil-fired boiler - 2 to 4 times a day the boiler will 'lockout' - a safety feature should the flame fail or ignition fail to give satisfactory start. A visiting engineer has replaced the motor as he thought the bearings were noisey and perhaps were 'sticking' when they got hot - this has not solved the problem... He's now stuck as he couldn't get the fault to replicate whilst he was here - obviously, now he's gone, it happens - though as I say, on an intermittent basis.



There's a reset button inside - which works everytime to restart it... - but clearly this is not good as I like the idea of automatic central heating...



Anybody with experience of this type of boiler here who can give any advice / pointer where to start looking?



Graham


I wonder if the wind is causing a failure - it's been pretty windy here recently.

Also is there a chance you have gunge or water or something in the tank? Does this happen?

Which model of burner is fitted to the boiler?

Could be a number of things. If I remember correctly, the last time this happened to me, it turned out the nozzle had got bunged up but I'd hope that would have been one of the first things your engineer would have checked.

Oddly enough, before I found my current boiler company (who know what they're doing) I had a visit from a freelance engineer who also thought the pump was faulty and replaced it with no improvement. Coincidence ? (You're not in South Dorset, are you ?)

Cheers,

John

Faults I have experienced with other brands of boiler include:

a) Paper filter on oil tank outlet becoming clogged because it had not been changed.

b) Air ingress through flexible hoses ( on two pipe supply)

c) Soot build up on photo cell because jet had not been changed.

One of the commonest causes of these long/variable period lockouts is a failing solenoid coil of the oil pump. Is yours a Danfoss oil pump by any chance?

One way of trying to find the problem would be to acquire an oil pressure guage. These only cost about £15 and will show whether the pressure inside the pump is dropping when the flame goes out. Also usefull if you ever change the pump.

Apologies to all - I've been away...

Still have same problem tho - Yes, it is! it's a Danfoss BFP 11L3.... Some more info - now this may be a *complete* red herring, but.... The problem doesn't seem to occur when I have the front cover of the boiler off.....so far (and does happen when I put cover back on most of the times)...

Anything in this - it's probably me looking for some type of pattern!

Graham

One way of trying to find the problem would be to acquire an oi

pressure guage. These only cost about £15 and will show whether the pressure inside th pump is dropping when the flame goes out. Also usefull if you ever change th pump.

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might want to buy the manifold as well which would add to the price!

Put it this way. They are quite useful and don't cost much - unlike combustion analysers which deteriorate even if you don't use them.

replying to Graham Dean, ian nye wrote: hi,did you sort this problem as I have the same thing happening , lockout anything from 2 - 4 times , but fires up ok on reset , again seems to work ok with the front cover off

Graham probably hasn't been seen since 2005. I guess HOH users haven't figured out how to start a new thread.

NT

That tends to suggest that the flame sensor has sooted up and is only happy when it can see light from the room. The other one I have known cause trouble is a very slow leak overnight so that the initial lighting causes a dirty sooty flame. Check the photosensor and clean it.

Reset and no more excess oil to burn the second or third attempt works.

replying to Martin Brown, ian nye wrote: Hi Martin, the boiler seems to intermittingly run it's cycle then lock out before the restart I.e. this morning came on at 6am worked fine , reached temperature at 6.35 so stopped , cut back in fine a bit later , all worked normally until 7.30 when it locked out before restart , waited a short while pressed reset and it fired up , this was with the steel housing and front cover off , problem didn't start until a few days after I changed the flexible oil pipe that leads to the pump which was leaking , had it serviced and the engineer couldn't get it to lock out , but as always with these things started playing up during the evening and ever since (2 days ago) , works but a bit of a pain having to reset 2 to 3 times a night and once in the mornings , just wondered if it could be many other things . thanks

Having less trouble with the burner cover off might indicate the oil pump s olenoid is getting hot and has an intermittent temperature dependant open c ircuit problem. The air circulation around it is limited when the covers ar e on and the problem exacerbated. Try a replacement solenoid coil. Other possible causes Oil pipe is kinked Oil pump is stiffening up and rotating the shaft by hand can reveal this. Oil filter is clogged, either the one at the supply pipe from the tank or l ess likely the one in the pump. Firestop valve is not fully open and is partially starving the oil supply Lots more potential causes but let's not have all the fun at once.

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