Satronic/Honeywell 832.3 keeps failing

[freeoil]

Hi there. I wondered if any of you pro’s have seen a strange fault that I’ve had with my Oil boiler.

Long story short, boiler failed to operate when requested. Not in lockout, had a quick check - I’m an industrial control electrician so handy with a meter - couldn’t find much wrong with photocell, solenoid windings etc so started to check the control box out. On inspection I noticed that one of the soldered connections to the heater coil on the bimetallic strip had become detached. Thus when the boiler got the 240v to fire the ignition sequence wouldn’t start as the bimetallic strip wouldn’t heat up. Awesome I thought, it’s a dodgy box. Shelled out £30 for new and hey presto house is warm, wife is happy.

Fast forward, 4 months and exactly the same fault. Strange, I thought so once again checked everything obvious because now I’m suspecting the boiler is killing the box. Nothing I could find apart from having no oil - doh! It then occurred to me that the original time the fault happened I had low oil! But surely this would just cause a lockout??

Anyway, swapped the box - again - to get up and running and stripped the dodgy box down. I resoldered the connection and it’s back to working order. I decided to have a play with it and see if I could get it to fail and I could, by running it through start cycle after start cycle on the bench (putting 240v on and waiting for lockout resetting the lockout as soon as possible then restarting) I noted how the bimetallic strip was starting to hold some heat and then melt the connection solder. At this point I figured I knew what caused the box to fail but couldn’t explain how the conditions on the bench could be replicated by the boiler.

Fast forward another 7 months and once again box has failed with exactly the same failure mode.

Any thoughts appreciated

If you're heating engineer can not find anything obvious wire a new control base.Even if the boiler is short cycling it will take more than several months to burn out any components as those we burners are bomb proof.

 

[freeoil]

Wow just realised this is from 2019 and its 7 down from the freshest post.

 

[SimonG]

Sparking too much.

 

[John Moncrieff]

Sparking too much.

Wondering if damp is the problem as my churches one does the same

 

[John Moncrieff]

Wondering if damp is the problem as i=the one in our church crypt also fails regularly