Oil boiler not firing after tank ran out

[regsmyth]

Stupid I know.

It's an Riello 40 G2 in a Boulter Camray 15/19 external wall mounted - at least 15yrs old.
However it has been running fine recently, but ran out of oil 3 days ago. Had the tank refilled this morning, and although the first couple of goes at the reset didn't work, it then fired, and I ran it for 30 secs. Then I switched it off, put cover back on etc, but then it wouldn't start again.
I have bled the valve, lots of oil coming out when I press start and take the bolt out (no bleed nipple).
So I get the air fan for 10 secs, then a click and hum for 5 secs or so, then nothing. Photocell clean.

Any ideas anyone?
Thanks for any pointers.

 

[regsmyth]

I've had a look at a few other threads and Riello technical info.
I took the burner out so I could see the nozzle/electrodes - after 10 secs the electrodes started sparking, but no oil coming from nozzle. Then lock out.
I took out the photocell, but no still no ignition.
I'll have a play with the multimeter now and see if I get anywhere.

 

[muggles]

Could be muck in the oil filters somewhere along the line

 

[regsmyth]

Thanks for the thought - however if oil is pouring out of the pump when I remove the bleed screw, I assumed this means the oil supply is ok. Doesn't it?

 

[muggles]

There's a filter in the nozzle....

 

[regsmyth]

So I took out the nozzle - it's clean and clear.
When I first tried to bleed the pump, I unscrewed the pressure adjustment screw mistakenly. I screwed it back to where it was (more or less). I don't know if that will have affected it. When I run it out of the boiler, I can see the electrodes sparking, but there's nothing coming out of the nozzle. Which way would the screw turn to increase the pressure?

I also checked the solenoid resistances against a Riello troubleshooting chart and they are pretty close.

Any thoughts what to look at next?

 

[Aquaheat]

The phone number for a decent engineer?!

 

[oilhead]

There is a possibility that the filter in the pump is clogged. You are still likely to get oil from the bleed port. If you try starting without the bleed screw in, when you hear the click, does the oil flow increase? The Riello pumps give a 'wash' pressure of about 50 psi until the solenoid opens, then increases to 125 ish on your boiler. If you have drawn some contaminant through to the pump, or on a wall mounted boiler you may have tried too many dry starts, then the pump will give up the ghost, especially if it is 15 yrs old.

 

[regsmyth]

Thanks Oilhead. Ok so I took out the bleed screw (slight sucking noise), then pressed start. Oil squirts out. At 10 secs, there is click but no change in squirt pressure.
I read somewhere that you can also bleed from the vacuum port on the side, but when I unscrewed this, nothing came out, even when motor was running before lock out.

I have left a message with oil engineer, but still trying to work it out myself if poss.

Thanks

 

[oilhead]

It sounds as though the pump has failed, but given you have moved the adjuster, without a pressure gauge, it is difficult to go any further.

 

[regsmyth]

So I've taken the pump out and starting to dismantle it. I was hoping to find the plastic coupler was broken, but it seems fine. Can anyone tell me how a pump is likely to fail or what I should be looking for? Also I can see a number on the pump 6076 0041 - but this doesn't seem to match any Riello pump numbers I've found online.
Plumber hasn't got back to me, so any thoughts welcome....

 

[Burnerman]

The only way to really test the pump is with a pressure gauge - presuming it is spinning! If it can reach and exceed the manufacturers requirements it should be fine.
Check out www.hwos.co.uk and you'll probably be able to identify it.
John

 

[regsmyth]

Thanks John, well I took the pump to pieces and apart from a little debris on the large filter, it all seemed ok, so I put it back together - and it's working again! House warming up, kids happy.
A few drips to deal with tomorrow, but all seems good (famous last words). Have to get the pressure checked soon.

Thanks to all for help!