Hot water temp needs to be high for central heating to work

by **neilm** » Thu Jan 08, 2009 6:00 pm

I have a potterton suprima 50 coventional boiler, with hot water tank, pump and motorised valve set-up. The problem i am getting is that i noticed the central heating was cuttting out before the room temprature was reached. Changed the room thermostat but still the same. After some playing with controls ive found that when i turned the hot water tank thermostat upto 60 the heating cut in and worked fine for a week. Then it happened again and i turned the hot water thermostat upto 70 and it has started working fine again. The hot water tank thermostat was replaced last year. Any ideas

by **Steve the gas** » Fri Jan 09, 2009 5:57 am

Hi Neil,

I would begin with checking the MV for correct operation, is the slider slack with no resistance?

by **neilm** » Fri Jan 09, 2009 7:32 pm

Thanks for the reply. The motorised valve slider does seem to have no resistance when i move the slider