Powermax 155 CH pump wont switch on

[BurtonBloke]

My Powermax 155 will not start the central heating pump. I had an engineer on site to day but he could not trace the root cause of the fault.

There is residual current going to the pump, not 240v and the pump is known to be working (tested on direct mains current via 3 pin plug)

The boiler will light and run until the system overheats and the overheat switch kicks in (due to CH pump not working)

I am able to use the reset button and the system restarts OK.

I am now running the CH pump from a wall out let and the system is delivering CH and HW as expected

I would be eternally grateful if any one has any ideas where the root cause of the problem may lie as my local engineer is stumped.

Thanks

Vince

 

[Gas2Air]

Cold start stat, this switches the pump on when the store is above 70c, they fail, link it out and see if the pump comes on then.

I would get the engineer back to check this though.