Potterton EP3000 CH/HW controller clock reset problem

[grapheve]

I have a Potterton EP3000 CH/HW controller that keeps re-setting the clock to default (midnight) when it is due to turn the heating or the water on.

When I try to reset the clock it defaults to midnight as soon as you scroll the time past any of the preset on/off times.

I am gong to replace the battery which is leaking.

Can anyone explain the problem and will a new battery fix the it?

Many thanks

[Steve S]

The leaking battery is most likely the cause of the problem. The stuff leaking out of the battery is conductive. Quite likely it is shorting out tracks on the PCB. Since the chip inputs tend to be very high impedance, the conductivity of the leakage is probably more than enough to cause the kind of problem you are seeing. Isolate the controller from the mains. Dismantle it. Ensure you remove all traces of leakage. I'd advise the use of deionised water for cleaning -- you can buy it from the chemist's. Swab it, don't immerse it. Remember that the battery contents may be toxic. Ensure the PCB assembly is dry before reassembling.

HTH, Steve S