Hot water / overheat cutout

[mike_j]

I have an old Worcester Heatslave Highflow boiler (model 41-311-39) - with a few issues.
I have had problems with having both central heating and hot water on at the same time, I have now remedied this by changing the 3 port diverter which was faulty, only to find the thermastat on the hw to be faulty - this has now been changed as well. But now hot water and central heating work seperately, but the hw now trips what I presume is an overheat trip as it shuts down the boiler and the pilot light.

Can anyone recommend where I could also get a pump overrun switch / pcb

 

[COG]

The highflow uses a pump overrun board that should be available at any decent spares outlet. The board will overrun for 5 mins after a demand has finished and when the power is re enstated . Run the boiler on dhw upto temp and shut down the timer and the stat if the top pump stops then you need a board. Dont use GC numbers so dont no if you have a 3.5 or 4.5 if its the 4.5 then dont worry about the lower pump its just to circulate the heat in the heat bank.