I've got a Potterton EP2 programmer linked to a conventional Worcester18ri boiler. The programmer has seperate sliders for HW and CH.
The CH slider works perfectly when sliding to 'on'......the red light comes on, and the boiler clicks on within the usual few seconds, so no problem.
However, with the HW slider, if the slider has been in the 'off' position for more than a couple of days (we were away for a weekend), the boiler sometimes fails to click on when sliding the switch to 'on' or when it is programmed to do so. The red light signifying 'on' comes on but nothing happens.
I experimented a bit. I turned on the CH as normal for five or ten minutes, and then turned it off. Then I slid the HW slider to 'on' and it suddenly works fine. (it's as if something has warmed up). The main problem is the early mornings when the CH is not needed, but HW is. Sometimes the HW will not click on when programmed to do so. It's intermittant.
I reprogrammed the controller in the hope things would correct itself. No luck. I've checked the thermostat on the HW tank and that seems fine, as the boiler turns off once temp has reached 60c (although I suppose it could still be faulty). The wires inside the program controller appear fine and tight. I suspect a faulty programmer but a new EP2 ( which is the easy option as same back-plate) is about £120. Any other ideas before I potentially waste my money on a new one? Oh, and by the hot water tank I have two separate zone valves, one each for HW and CH if that is of any relevance.
The CH slider works perfectly when sliding to 'on'......the red light comes on, and the boiler clicks on within the usual few seconds, so no problem.
However, with the HW slider, if the slider has been in the 'off' position for more than a couple of days (we were away for a weekend), the boiler sometimes fails to click on when sliding the switch to 'on' or when it is programmed to do so. The red light signifying 'on' comes on but nothing happens.
I experimented a bit. I turned on the CH as normal for five or ten minutes, and then turned it off. Then I slid the HW slider to 'on' and it suddenly works fine. (it's as if something has warmed up). The main problem is the early mornings when the CH is not needed, but HW is. Sometimes the HW will not click on when programmed to do so. It's intermittant.
I reprogrammed the controller in the hope things would correct itself. No luck. I've checked the thermostat on the HW tank and that seems fine, as the boiler turns off once temp has reached 60c (although I suppose it could still be faulty). The wires inside the program controller appear fine and tight. I suspect a faulty programmer but a new EP2 ( which is the easy option as same back-plate) is about £120. Any other ideas before I potentially waste my money on a new one? Oh, and by the hot water tank I have two separate zone valves, one each for HW and CH if that is of any relevance.
