Boiler runs ok when cold and lasts about 30 minutes

[Tom Gorrian]

I have a 10 year old oil boiler has run well and gets serviced every year all tests are spot on, last week started locking out, would reset and run for short time, engineer fitted new control box and said thats it he was only away 10 minutes and it locked out, now waiting on new photocel, boiler will run and start correctly but when warm after 30 minutes will go to lock out, starts again after 10 minutes then may run for 15 minutes and lock out. any clues

 

[SimonG]

Yes, your engineers a muppet. Issue needs fault finding and not chuck parts at it.

Let's have a few more details. Boiler make, burner make, what were the flue gas details like I.e. co co2 excess air etc.

 

[schubes18]

Tom, did you get to the bottom of your issue and what was it? I have exactly the same thing going on with my Firebird C26 external combi and a new photocell plus various other parts (have had 2 new control boxes in 5 years and boiler only 7 years old!) have still not fixed the locking out problem… exactly as you have described!