External oil boiler tripping on overheat

[Alemco]

hi
im oftec registered
boiler problem is on a camray 5 external
replaced overheat stat
serviced
modified shoddy pipework indoors
replaced circ pump
replaced cylinder stat
still tripping
replaced overheat stat again, just in case tripping again

 

[Dotty]

You've a circulation problem. I'd also check the operation of your control stat.

 

[SimonG]

You've done a lot of unneccessary work for an over heat stat tripping. Why?

 

[Killy Bing]

Does it fire up and go straight to over heat or does it satisfy the demand then over heat?

What nozzle and pump pressure do you have?
correct pattern?

 

[Alemco]

You've a circulation problem. I'd also check the operation of your control stat.

croppie
forgot to mention, changed the boiler stat as well

 

[Alemco]

why is that then Simon

 

[Alemco]

Does it fire up and go straight to over heat or does it satisfy the demand then over heat?

What nozzle and pump pressure do you have?
correct pattern?

done a full service on it killy,

 

[kris]

You said you replaced the pump what was the water like when you disconnected the pump?

 

[Alemco]

You said you replaced the pump what was the water like when you disconnected the pump?

Have to say I didn't check, pump valves worked fine. Got to say the system seems fine when I'm there and circulating ok
it seems to trip once a day after coming on for the early evening shift, so it does the early morning, no probs, then come the afternoon/evening goes to o/h lockout

 

[SimonG]

why is that then Simon

So you don't know why you've changed the bits you have then?