Riello 40 G2 Control Box Burning Out

[LeClerc]

Hi, I have a Riello 40 G2S burner in my Camray 15/21 boiler (approx 20 years old).

Recently, I've had problems with it locking out (burner lock out) and finally traced it to the control box - which I replaced, along with a new photocell. Along the way, I've also replaced the pump drive coupling and the capacitor. The boiler was serviced by a professional company about 6 weeks ago.

Around 4 weeks ago, the old control box burnt out - i.e. the fan would run for about 1 second and then the control box lockout lamp would come on and the motor would stop. Repeated resets resulted in the motor running for anything between 1-5 seconds and then stop. Clicking from either the control box or the solenoid (it was hard to tell which) indicates that something was working.

The replacement control box cured the problem for about 4 weeks, now the new control box has burnt out in the same way. I am just about to buy another replacement control box along with a solenoid coil - however does anyone have any ideas why this would be happening?

Many thanks in advance for any help 🙂

 

[SimonG]

Whats the position of the electrodes like or is there something shorting out the electrodes?

 

[LeClerc]

Hi SimonG, thanks for replying - I'd checked the electrodes a few weeks ago and checked them against the settings laid out in the manual. Haven't checked them since though.

(The boiler had been running perfectly for 4 weeks since I replaced the control box and had been for an hour up until it locked out.)

 

[Best]

How can you be sure it is the control box? That type is very reliable. As are the solenoids. Are you sure the oil pump is working?

 

[Best]

If you haven't had the box checked, then be careful before you buy another one. It could be coincidence that something else is wrong.

 

[LeClerc]

I'm 99% sure that the pump is working OK - although it doesn't run long enough to check (i.e. loosening the gauge screw and looking for oil squirting). There is definite smoke and and acrid electrical-type burning smell emitting from the control box - even when the fan runs for less than a second.

 

[LeClerc]

I'm thinking along the lines that something else is wrong and is causing the box to burn. The old box (the one I replaced) was clearly the original, which must have been in there for a good 20 years.

 

[Best]

I have never seen this before. Check all the wiring & connections for box. Check the electrode block also.

 

[lance]

Check the brown and black wires are tight. (the same terminals as capacitor wires) Tug 'em with long nose pliers.

 

[LeClerc]

Will do. I'll check all of the electrical connections to the control box plate. (I didn't replace the plate when I replaced the control box, so maybe I'll replace that one too.)

 

[Best]

If you replace anymore parts you will have spent too much! You can buy a new burner for less sometimes!

 

[LeClerc]

The thought had crossed my mind! I can pick up a Mectron 3 (which looks like the modern equivalent) for about £460!

 

[lance]

No need to replace base!!! But I have fried a control box.....after I fitted a capacitor.. lovely smell..

 

[Best]

£460 is too much. I don't know the exact price as I don't buy them, but that is definitely high.

 

[SimonG]

£460 is too much. I don't know the exact price as I don't buy them, but that is definitely high.

About 1/2 that plus fitting!

 

[Best]

About 1/2 that plus fitting!

I didn't like to say that! But that's about what I would expect to pay for it! Sterling burners are sold where I am at little more than £200! Excellent, easy to work at & usually reliable, they are.

 

[SimonG]

I didn't like to say that! But that's about what I would expect to pay for it! Sterling burners are sold where I am at little more than £200! Excellent, easy to work at & usually reliable, they are.

About the same here and yes they are excellent.

 

[LeClerc]

No need to replace base!!! But I have fried a control box.....after I fitted a capacitor.. lovely smell..

Interesting. I had replaced the capacitor prior to this problem happening.

 

[LeClerc]

Checked the electrodes, they're clear of anything and aren't shorting.

There's oil at the nozzle (when it runs long enough).

I've removed, cleaned and checked the control box plate and remade all of the electrical connections so I know they are now sound.

Capacitor is checking out at 3.75uf though - under the impression it should be 4uf?

Can't do anything else now until new control box arrives!