Boiler overheat keeps tripping

[carl1959]

I have a old system that has been overheating and tripping the trip.
I have replaced the thermal overheat stat and still trips can you suggest any reasons and solutions for the problem?
The boiler is a ideal Turbo 2 (12) wall mounted boiler.

 

[ollski]

pump sticking , blockage, faulty boiler stat.

 

[Agile]

Or just sludge in the system!

 

[namsag]

Try changing the actual boiler stat because if that has gone it would cause boiler to overheat and trip the overheat stat.

Ideal turbo 20 year old condensing boiler, if memory serves me right one fixed stat set at 82 degrees

 

[carl1959]

I will clean out the system of all sludge and try again.
Many thanks to the quick responces.