IMI POWERMAX 155

[FIGFIG]

Having on going problems with my boiler. Runs ok from cold then as it heats up the cylinder sounds like a washing machine or kettle that wont switch off! After a while the trip switches go which are connected to the thermal rods in the cylinder!
Any help much apreciated?

 

[baxpoti]

It's overheating

 

[lor]

pump failure

 

[FIGFIG]

I'm starting to think that now. but which one even though they are both running? The central heating flow part Gold No 027 or Gold No 077 at the bottom not labeled but presume is for hot taps etc!