OFF TOPIC! Programmable timer problem

I wonder if one of you solar heater experts or fish farmers etc. might help. Arduino is not involved with this part of the job.

I have a programmable timer on the water heater. It works OK but is hard to read as every display item is visible i.e. the time shows as 88:88, as in the pic. There is an internal battery, and it reads fine if I turn the power off. I therefore assume that AC power is the cause of the problem. I was hoping that I can fix this by re-arranging the wiring and/or moving the timer to the other end of the sub-board shown (very small).