Potterton EP2002 - No Central Heating

oysterpearl

Hello,

We have a Potterton EP2002 programmer linked to a Baxi PFL boiler. We are usually able to switch on heating or hot water independently of each other with no problem. However, when the hot water is on (on it's own) sometimes some of the upstairs radiators will go on.

Yesterday, we had the heating on in the morning, switched it off and then turned it back on a few hours later. The boiler didn't fire up when we moved the slider onto ON. However, if we tried to put the hot water on, it worked fine. Also, with the hot water on, the radiators upstairs and one of the ones downstairs all came on and the water heated up.

The programmer switch has always been a bit tempermental - you have to push the slider in for CH rather than just slide it on, so from that and from a few things I had read on the internet, I thought the programmer was at fault. I bought another EP2002 this morning and replaced the old one.

However, the same problem is still there. If you slide the CH switch over to ON, nothing happens. If you slide the HW switch over to ON, the boiler fires up and seems to be heating water and some of the radiators.

Does anyone know what could be causing this?

Thanks for any help.