Oil boiler just serviced and now short cycling?

[Diablo]

All,

 

 A few days ago, my oil boiler stopped firing.  It was literally 12 months to the day that it was last serviced. 

 

The engineer came out and did a regular service i.e. cleaned the baffles, changed the nozzle etc and would not fire.  He then changed the optical sensor, and the boiler fired up.  At this point I had to go out, but left the boiler running.

 

Yesterday, I noticed that the burner was short cycling, which is something that it has never done before. Generally, the burner runs for about 10 seconds, but it sometimes fires for only 2 seconds and shuts off.

 

I mentioned to the engineer this morning that something has changed since the service and that it never short cycled before, but in true 'engineer' fashion he rattled off a list of things that he thought needed replacing on the boiler, if not the actual boiler itself...all the while ignoring what I was telling him: "But it never short cycled before you serviced it..."

 

Does anyone have any thoughts on what might have happened?  I should add that the heating (UFH) was off for nearly two days, so the slab did require a lot heating to get it back up to a reasonable temperature.

 

Thanks in advance,

D

 

 

 

[Nickfromwales]

You may do better to ring the technical dept of the boiler manufacturer and ask them what would cause such an event. Definitely sounds like the 'engineer' has done something wrong. 

Is the temperature dial set as it was before?

[richi]

Stupid questions:

• Is the pump pumping?
• If so, did the engineer change the pump speed?

[Jml]

Ours started doing that at the end of last year, was faulty photocell, total bill approx £100, parts and labour.

[dpmiller]

Is it going into lockout (red light on?)if it's only running for a few secs and the boiler is defintely cold I'd definitely look at the photocell. If the boiler is hot then I might consider the pump...

[Diablo]

2 hours ago, Nickfromwales said:

You may do better to ring the technical dept of the boiler manufacturer and ask them what would cause such an event. Definitely sounds like the 'engineer' has done something wrong. 

Is the temperature dial set as it was before?

 

Hi Nick,

I called Warmflow and their view was that it is do with 'flame establishment' i.e. something within the burner is causing it to switch on and off.  One of the things he suggested was faulty photocell, which the engineer replaced. He did increase the temperature, but I changed it back to where it was before.

 

2 hours ago, richi said:

Stupid questions:

• Is the pump pumping?
• If so, did the engineer change the pump speed?

 

Hi, Yes, it is pumping.  I am not aware he adjusted the pump speed, but now that you mention it, will ask the question.

 

2 hours ago, Jml said:

Ours started doing that at the end of last year, was faulty photocell, total bill approx £100, parts and labour.

 

Hi, he did change the photocell,  but obviously it can still be at fault and will b checked again.

[richi]

Just a note that my pump questions are probably a red herring. I missed your comment about it only running for 2-10 seconds. I agree with others' best guess it's the photocell (boiler thinks it has failed to light and shuts off to prevent unburned kerosene being squirted everywhere).

 

(When I read "short cycling" I assumed you were talking about a few minutes, as if the water wasn't taking the heat away fast enough, causing the loop 'stat to kick in.)

[dpmiller]

Ah... hang on a mo. Is this a Riello burner?

If so my neighbour just had this happen.

Oilpump.

Would make pressure on purge, but as soon as the solenoid opens pressure drops to zero. Brief puff of flame then nothing. I opened the pump and it was full of glittery bits.

[Onoff]

Done the pump in my Riello a couple of times.

 

There was a "fix" sometimes on these whereby you could replace a little key on the shaft that disintegrates from memory.

 

Plumbcentre do the pumps but are 'kin expensive so shop around!

[dpmiller]

I was only asked to bleed it following an outage and when diagnosed it was handier to get her to call the local OFTEC guy as he's at the far end of the estate  and I was away working the next day anyway. We both use the same trade outlet.

[Onoff]

If I run out of oil I need to bleed pretty much every time. Otherwise hitting the burner reset button and it'll attempt to fire up then die due to fuel starvation. It's a doddle tbh. Get a tray under the burner. An old Neapolitan ice cream tub helps too. Unscrew this Allen screw, think it's 4mm (I only had a 5mm to hand). Unscrew it but keep very readily to hand. Hit the reset button a few times and you'll hear a hiss of air. Eventually you'll be rewarded with a steady stream of stinky heating oil. Whack the screw back in and then spend the rest of the evening trying to get the smell off your hands!

 

 

Worth checking any filter too and that the fire valve hasn't tripped.

Edited February 26, 2018 by Onoff

[Diablo]

Hi, yes, it is a Riello RDB 2.2 burner.  I should say that the burn time is quite random and currently varies between 2 seconds and about 10 seconds.

[Onoff]

I'll Whatsapp my boiler guru who is to boilers what the Welshman is to plumbing! 

[Diablo]

OK...just made an interesting discovery...

 

The burner fires for 20 seconds - stops - fires for 1-2 seconds - stops - fires for 20 seconds.   This pattern is repeated continuously.

 

However...

 

If I remove the front panel of the boiler, it burns as normal.  As soon as I out the cover back on, it reverts back to the pattern described above.

 

I should also add that there is more of an oil fume smell since it was serviced. 

 

If you can run that past your boiler Guru, it would be much appreciated.

[Onoff]

18 minutes ago, Diablo said:

OK...just made an interesting discovery...

 

The burner fires for 20 seconds - stops - fires for 1-2 seconds - stops - fires for 20 seconds.   This pattern is repeated continuously.

 

However...

 

If I remove the front panel of the boiler, it burns as normal.  As soon as I out the cover back on, it reverts back to the pattern described above.

 

I should also add that there is more of an oil fume smell since it was serviced. 

 

If you can run that past your boiler Guru, it would be much appreciated.

 

Sorry, "front panel"? What bit's that then?

Edited February 26, 2018 by Onoff

[Onoff]

7 hours ago, Diablo said:

Yesterday, I noticed that the burner was short cycling, which is something that it has never done before. Generally, the burner runs for about 10 seconds, but it sometimes fires for only 2 seconds and shuts off.

 

He's come back ref the above when I asked could it be the photocell:

 

 

"Yes to prove cover or remove cell to clean other possible causes fuel starvation or   Air problems normally associated with tigerloop or as you said  dirty or faulty photo electric cell"

 

Will now ask ref it working ok with the "cover" off. Do you mean the lid of the boiler or what?

[Diablo]

The front of the boiler is a removable panel that gives access to the burner, thermostat etc.

[Diablo]

2 minutes ago, Diablo said:

The front of the boiler is a removable panel that gives access to the burner, thermostat etc.

 

[Onoff]

Sounds like a simple loose connection to me but let's see what he comes back with. 

 

Just had my Mum and Dad's gas boiler dead as a dodo. Pushing the airing against the control centre at the back of the airing cupboard and everything was ok. Took the cover off the wiring centre and wiggled the wires...sparks galore and I found multiple loose connections. This is under a BG service contract and Dad's a BG pensioner. I reckon sometimes these bastards leave a few bits loose for a g'teed call out in the future!

[Onoff]

44 minutes ago, Diablo said:

OK...just made an interesting discovery...

 

The burner fires for 20 seconds - stops - fires for 1-2 seconds - stops - fires for 20 seconds.   This pattern is repeated continuously.

 

However...

 

If I remove the front panel of the boiler, it burns as normal.  As soon as I out the cover back on, it reverts back to the pattern described above.

 

I should also add that there is more of an oil fume smell since it was serviced. 

 

If you can run that past your boiler Guru, it would be much appreciated.

 

OK, I asked him if it could be a loose connection:

 

"Could be but sounds like it’s the cell, is their any noise associated with the problem? Could be a loose or heat damaged wire or faulty thermostat or something.

 

Give him my number if he needs a chat !"

[Diablo]

1 hour ago, Onoff said:

 

OK, I asked him if it could be a loose connection:

 

"Could be but sounds like it’s the cell, is their any noise associated with the problem? Could be a loose or heat damaged wire or faulty thermostat or something.

 

Give him my number if he needs a chat !"

 PM Sent

[Onoff]

3 minutes ago, Diablo said:

 PM Sent

 

Replied.

[Simplysimon]

3 hours ago, Onoff said:

 Whack the screw back in and then spend the rest of the evening trying to get the smell off your hands!

 

 

disposable gloves?

[Onoff]

11 minutes ago, Simplysimon said:

 

disposable gloves?

 

Nah! Heating oil's magic, it gets through anything!

 

Tbh I do use gloves but always seem to get the odd splash on me. 

[ProDave]

This is where I like outside boilers. You can remove the burner, point it away from the boiler and fire it up with the flame visible and really see what is going on. Do NOT try that with an indoor boiler