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?

 

[Alemco]

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

from experience and a word from Worcester techies, the boiler stat and overheat stat were changed whilst doing a service enabling to keep the cost down for the customer and me from travelling too far for some simple that I may have overlooked, so took the techies word and fitted.
Whilst originally talking to this new customer he assured me that the circ pump was only two years old and besides, he also said that the airing cupboard was totally chock a block and didn't want to empty it.

A subsequent visit proved that a previous installer had made a proper pigs ear of the pipework so when I had rectified this the circulation improved drastically, so much so that the owners stated the the two living room rads had not worked this good since the change over to the external boiler ten years ago.
however the problem persisted, I persuaded the customer to empty the airing cupboard so I could fit a new pump whilst doing so I noticed the cylinder stat was not working correctly so changed whilst there.
I havnt charged for the pump the cyl stat or labour for last visit coz I have not managed to solve this problem.

 

[kimbo]

Is there any air in system coming to rest at the boiler

 

[SimonG]

from experience and a word from Worcester techies, the boiler stat and overheat stat were changed whilst doing a service enabling to keep the cost down for the customer and me from travelling too far for some simple that I may have overlooked, so took the techies word and fitted.
Whilst originally talking to this new customer he assured me that the circ pump was only two years old and besides, he also said that the airing cupboard was totally chock a block and didn't want to empty it.

A subsequent visit proved that a previous installer had made a proper pigs ear of the pipework so when I had rectified this the circulation improved drastically, so much so that the owners stated the the two living room rads had not worked this good since the change over to the external boiler ten years ago.
however the problem persisted, I persuaded the customer to empty the airing cupboard so I could fit a new pump whilst doing so I noticed the cylinder stat was not working correctly so changed whilst there.
I havnt charged for the pump the cyl stat or labour for last visit coz I have not managed to solve this problem.

Fair play to you.

I take it the evening programme is longer?
Any heat transfer paste on the control stat when you changed it? Another control stat?

 

[Killy Bing]

Assuiming its on an s plan does it and an automatic bypass???

 

[Alemco]

Is there any air in system coming to rest at the boiler

I really can't say if there is or isn't kimbo, there is an old AAV that has seen better days. I was thinking of rigging the pump up so that it ran 24-7 just to see if it could be latent heat or air trapped, so if it just kept circulating at least I could narrow it down a tad