could anyone offer some advice here. went to do landlords. a day before ,the tenant could turn off central heating without turning off mains. did the landlords and going back in twodays. potterton puma 80e. hotwater fine but ch on constant even though stat, program and ch switch on boiler is off!!!! had a look at m.i. and there doesnt seem to to be any c'h flow switches that could stuck. one chap as told me that if you pull off the c/h ptc it will fire up?? sounds implausible. any ideas. thanks