Oil burner short cycling

[Alipacino]

Hi is it possible that water in my oil tank is causing the system to short cycle? Plumber says that's the only thing it could be after troubleshooting.

Thanks

 

[SimonG]

Need a few more details than that! Type of boiler, type of burner, what it's actually doing? i.e. is it running for a couple of minutes and cutting out etc etc etc

 

[Alipacino]

Need a few more details than that! Type of boiler, type of burner, what it's actually doing? i.e. is it running for a couple of minutes and cutting out etc etc etc

Sorry. All I know is that it's a riello 40 and there's definitely water in the oil. When first turned on it runs for about 15 mins then it stops firing for roughly 2 mins then on 2 mins and so on. The radiators are boiling hot almost instantly when it fires up . Plumber checked pump, cleaned filter etc so has said he thinks it's the water causing cycling. Sorry if that's still a bit vague but I'm clueless.

Alison

 

[dontknowitall]

Is it an open gravity or sealed system? (No idea what I mean? Is there a pressure gauge and/or a red tank thing?)

 

[SimonG]

I take it your plumber doesn't do much oil work?

If you have water in the tank then the first thing to do is get it out.

New filter or reclean depends on type, flush through oil line and new nozzle.

Pressure gauge on and then go from there.

 

[dontknowitall]

I don't reckon there's any water in the oil or the boiler wouldn't be running for quarter of an hour or so.

imho!!

 

[Dotty]

I don't reckon there's any water in the oil or the boiler wouldn't be running for quarter of an hour or so.

imho!!

Wouldn't be running at all.

Blocked filter imho.

 

[lame plumber]

might want to check whether your guy is oil qualified and experienced based on what you have said

 

[Nostrum]

Short cycling is gonna be because the boiler is oversized or there's a restriction somewhere stopping the heat being dissipated, boiler is going off on high limit stat and then firing once cooled. Possibly a circulating pump issue and if the boiler has anti short cycling feature then it cannot fire within a Pre defined time scale after going off. If that was the case though I'd expect the radiators not to be red hot top to bottom.

also very inefficient way of heating your home!

 

[Best]

Riello 40 will attempt to restart straight away if anything makes the flame cut out.
It could be anything, but control box or solenoid could do this. As it is only 15min till it starts cutting on & off, I would push a new control box on & wait the 15min!
Riello oil pumps can fail intermittently.

 

[Alipacino]

Thanks everyone....decided to get a reputable oil heating engineer out through my insurers.

Xox

 

[SimonG]

Thanks everyone....decided to get a reputable oil heating engineer out through my insurers.

Xox

Just on that note. I fixed a boiler last week that the AA had been out to 5 times, the bloke was pulling his hair out and the AA have 1 less customer.

Hope you get it sorted.

 

[Bunker]

Im with Sambotc - the boiler is short cycling, not locking out so its unlikely to be burner related.

If it was the pump failing Id expect to hear that only the rads upstairs were warm, not that any were red hot.

As its coming on and off, I cant see it being the boiler stat as it sounds like thats doing its job.

Wont be the high limit stat as again, its coming back on by itself.

So what does that leave - cylinder/ air stat? As the rads get hot, it would suggest its air stat and not cylinder - so do the symptoms occur when running Hot Water only? That would narrow that down to boiler or air stat unless its air trapped in the system, for example in the manual bleed you often get above the pump/ 3 port valve.

(question: is the pump running? is is getting very hot? is the pipework one side hotter than the other?)

Back to water in the oil:
There may well be water in the oil but the boiler would only woof every now and then or just simply lock out, not cycle.

The above is not atall comprehensive but further things to look into.

 

[Best]

Im with Sambotc - the boiler is short cycling, not locking out so its unlikely to be burner related......

The Riello 40 (rdb also) will often NOT lockout but fire up immediately after a fault cuts it off, - like a faulty oil pump or control box etc, so can easily be the burner. They can run on & off like this forever.
I have also seen a condensing oil boiler cycling in 2 min intervals which I believe to be the fault of severe heat loss in pipes that go through a garden from the boiler in the garage to a house about 6metres.

 

[Bunker]

The Riello 40 (rdb also) will often NOT lockout but fire up immediately after a fault cuts it off, - like a faulty oil pump or control box etc, so can easily be the burner. They can run on & off like this forever.

I didnt know that, now I do. thanks.

 

[derek hunter]

remember water will drop to bottom of tank so it wouldnt cycle it just wouldnt fire i would suggest there is a blockage

 

[Dannypipe]

Water in the oil doesn't cause short cycling!

Over sized boiler would be my first guess...or lack of proper boiler interlock.

I installed an oversized boiler in a house last year, ready for a massive extension being done this year. (Oil installation) I've run the pipe work in 28mm to a manifold ready for the new zones. Trying to commision it was a bit tricky as it quickly cycled on off.

Anyway, sack your old engineer, and get an OFTEC registered one.

 

[Alipacino]

Thanks guys.....a proper engineer is calling on tuesday (you'd think I would have learned by now that trying to save money usually ends up costing more) and it looks likely my insurer will cover it. I'll let u know when it's fixed and what was wrong.

Xx

 

[kimbo]

Most oil tanks have got some water in them from condensation etc. This in itself doesn't cause a problem with the burner, it is only when the water gets into the oil line and then is sucked into the pump or freezes that it causes problems. I went to a boiler.yesterday with the same problem and it was air in the oil. As best said the r40 will start again a couple of times before it goes to lockout if the flame is not established. You have done the right thing getting an engineer rather than a plumber.

 

[WHPES]

Check your tank top connections to make sure no water is getting in.

Like it has been said water in the oil is probably not your problem.