Very strange symptom - firebird boiler Reillo burner just blowing

[Firebirdfan]

Hi thanks in advance fire any help. My 20 year old firebird 90 boiler has run really well with only one control box and one photo cell changed 3 years ago. 3 weeks ago it started to flame out when trying to ignite when hot so I decided it needed its first proper service as I have done it myself until now. The engineer changed the flex pipe and adjusted the air to get the proper readings and it ran fine . When I went to use it again a few days later it fired, went up to temperature, refired, but on the third refire there was no spark, no flame but also no oil, just the blower going non stop. It repeats this sequence every time and never goes to flame out. What do you think? Any help greatly accepted.

 

[ChrisJP]

If there's no oil getting to the burner, but there is oil in the supply line (I guess you've checked this?), then the pump must have failed and needs to be replaced. I've had this happen on my old Worcester Danesmoor boiler and it took me a while to diagnose why it wouldn't fire up.

 

[Firebirdfan]

Thanks for the reply, full tank of oil and it fires for about 30 mins until it gets to temp. Then after one more heating cycle of o few minutes it the starts again but fails to spark , light or send in oil. It just blows. This indicates a good supply of oil so any other ideas? Cheers M

 

[Exedon]

As it's recently been serviced why not call engineer back?
Photocell first suspect when fan just runs.

 

[Firebirdfan]

I will also check the capacitor and the solinoid, would this meter be good enough?

AP DC DIGITAL MULTIMETER 600V​

 

[Firebirdfan]

As it's recently been serviced why not call engineer back?
Photocell first suspect when fan just runs.

Thanks for the reply, if it is the photo cell then as it is not a serviceable item would I not be charged as it would be down to coincidence and not the engineers fault. Therefore a dreaded chargeable service visit. He lives over an hour drive away as well.

 

[ChrisJP]

The other possibility is the solenoid coil on the valve that allows oil to flow from the pump to the burner. It's not unknown for this to fail when they get hot - which this one probably will do after 30 min operation.

 

[Firebirdfan]

The other possibility is the solenoid coil on the valve that allows oil to flow from the pump to the burner. It's not unknown for this to fail when they get hot - which this one probably will do after 30 min operation.

Thanks Chris,
I want to check the solinoid, which I think requires ohms K or M would this meter be good enough?

AP DC DIGITAL MULTIMETER 600V​

 

[Firebirdfan]

Hi all, here is an update . I got the engineer who serviced the boiler to come and look into the fault. It is now worse as it fires up from cold and when it gets to temp refuses to relight but now it also shuts off the flame when I close the airtight cover to the motor!! It still blows however and the odds no flame out light. Anyone with any ideas welcome. M

 

[Firebirdfan]

However he changed the capacitor but it still won’t work.

 

[Terrywookfit]

If I was on site my first step would be to fit a new box and cell to eliminate them,
Then for vitiated air in the snorkel if fitted, (balanced flue)

 

[Firebirdfan]

If I was on site my first step would be to fit a new box and cell to eliminate them,
Then for vitiated air in the snorkel if fitted, (balanced flue)

Hi Terry, I fitted a brand new control box and got the same symptoms. I haven’t changed the photo cell but it was replaced 3 years ago and has passed all the usual tests. It has a balanced flue leading to the outside but has worked for over 20 years and nothing has changed unless you can think of something. M

 

[Johntheo5]

Has it a concentric balanced flue like a Gas boiler or a separate outside flue and air intake?

 

[Firebirdfan]

It has the latter, an outside flue with the air intake positioned just behind the cone cover.
I have just seen this on another part of the forum, do you think this could be one part of the problem?

 

[Johntheo5]

Can you remove the flexible hose from the air box, leave the door of the heatpac or the boiler house or whatever ajar and see if it runs OK for a few cycles, if a indoor boiler take more care.