Riello RDB Lockout

[Datcher]

I have a Riello Burner RDB1 BF 70/90 0/1 Code 3748351 Type 483150 fitted to my Potterton Statesman Flowsure+. It has been randomly 'Locking Out' for the past month. The boiler fires up without problem and can run from anywhere between 1-2 hours to 5-6 hours and then locks-out.

I have performed the following to try and cure/diagnose the fault:

1) Bled the oil at the brass port - good pressure with clear oil. (No pressure gauge available although oil did spray across the garage when I loosened the bleed nipple too many turns)
2) Replaced Nozzle
3) Replaced photocell
4) Replaced solenoid
5) Voltage check at white wire from motor = 54VAC
5) Cleaned ignitor
6) Ran boiler with snorkel removed
and finally replaced Control Box today.

All of these resulted in the same initial problem.

I would be grateful for any advice on where to go next.

P.S. As I am now building up a stash of serviceable Riello spares - if anyone needs them for their van let me know.

 

[oilman]

Clean the fuel filter.

I hope you enjoy not fixing boilers as you have spent way too much money compared with getting someone to fix it.

 

[Agile]

I was thinking that you seem to be changing a lot of parts and with the control box comming to a reasonable cost.

Have you not considered that it might even be cheaper to call an engineer to service the boiler and let him take over in the unlikely even that any fault ever occured which is far less likely when an oil boiler is regularly and PROPERLY serviced.

Tony Glazier

 

[Datcher]

Thanks chaps. Just what I need, seemingly good advice coupled with cheap throwaway comments that are only of value to the author.

The boiler has been regurlarly serviced (and as far as I'm aware PROPERLY) and has just been repaired (overheating) while I was out on deployment.

 

[Burnerman]

Check the settling bowl at the tank filter for water / debris.
Its probably worth getting the pump pressure checked......have you noticed any change in the burner tone when its starting up?
See if its any better without the snorkel - is there any possibility that the thing misbehaves more in windy conditions?
Can you tell us about the overheating comment, and any repair that was made?
John

 

[oilman]

OP has already tried removing snorkel, and elsewhere in the country might be windy, but there seems to be very little of it today in most places.

One thing that hasn't been done is to check the capacitor value, which would cause this type of fault. Disconnect the mains, disconnect the capacitor and measure its value. Should be at least 4uF

 

[Burnerman]

Fair comment but there's not really that much left to replace......maybe the motor cap or pump solenoid valve is next!
OP needs to be sitting on the burner next time it gets grumpy
John

 

[Datcher]

Thanks Burnerman.

While I was away the Boiler would constantly hit the limit stat resuting in no HW/CH. The tank stat was a fault and was replaced. Don't see a link to the current problem?

I have considered the wind factor - only ever known approx 5-6 other lock out occasions in 6 years and no extreme wind currently. I have also ran it without snorkel to eliminate wind/recirculation issues with no effect.

There is also no discernable difference in pump tone as far as I can tell. Pump pressure - could you direct me to the sort of gauge and fitting I would need or is more of a proffessional bit of kit?

Many thanks.

 

[Burnerman]

No link between the overheat stat and the burner lockout lamp!
I don't have any certain data concerning that particular boiler I'm afraid but I think the RDB needs 145 psi and a CO2 of 12% in this set up - but I'm delighted to be corrected!
The pressure gauge fixes into the port below the pressure adjustment screw on the side of the oil pump - thats cheap to buy and easy to do, but the air adjustment is another matter, requiring flue gas analysis kit.
So long as the boiler internals are clean I'd be summoning someone with the correct equipment, I think, to check these settings.
John

 

[oilman]

CAPACITOR.