I have a potterton EP2000 up until today could have hot water without heating. Now I can't get water hot. Have tried heating and water together and radiators get hot but hot water remains cold. Any ideas?

janwads, July 2010

Probably a sticking diverter valve.
Other things to try:
Is the cylinder stat turned up and set at approximately 60c?
Is there 240v from the programmer HW output to the common terminal of the cylinder stat, likewise 240v out of the call on the stat to the orange wire on the diverter?

Carefree, July 2010