potterton ep2002 controller

just changed an old Potterton 2000 controller for a ep 2002, as soon as you bring in the central heating it takes out the trip for that circuit. Have checked out both pumps they are working ok, checked out wiring to pumps ok. disconnected thermostat and tank stat one at a time both ok. Initially system worked for 4 days after change of controller, seems to operate hot water system with no problems. Is there anyone out there who could suggest an answer to this nightmare

is that not just a straight swop (same backplate)?

why was it changed ?

I think the change of programmer is fascinating, but ambiguous.

Your post states that it worked satisfactorily for 4 days.

Therefore your problem is likely to be elsewhere.

You do not say what sort of 'trip' you are having. Day, Acid, or Ego?

I suspect that because the 3A fuse isn't blowing, you are describing an 'RCD trip', in which case the phase insulation to earth is being compromised. This can be caused by crushed wiring, or a faulty part such as a pump or a spectacularly damp boiler.

I'm having problems with my Potterton EP2002 controller. I have replaced it 3 times now in 12 months and they seem to run fine for about 3 months before they go wrong. When the go wrong they stay in the ON position and you cannot switch off the controller. All the buttons fail to work, you cannot switch it off, adjust the times or do anything with the settings on the controller. The only solution appears to be to replace the whole from panel of the unit. When I replace the panel with a new one it starts working fine and goes on for it seems about 3 months. Then just goes wrong with the same problems. Replace the front panel unit with a new one and everything is fine again for a few more months.
I have had 3 controllers now in 12 months.
Why is this happening?
Sandie
Any advice or help would be very welcome.