Oh dear……

Off to the Bowls Club in a neighbouring village to repair some frost damaged plastic pipework.
Replacing the pipe work was ok, but when completed the pump wouldn’t run. Turned out this control unit was half full of water. It’s what happens when keen amateurs do electrical jobs……they leave out the seals in the cable glands so when the pipework leaks the water runs along the cable and fills up the electronics housing.
The replacement controller costs £230, and is on order.
An expensive job.