Rads in one room only warm up when hot water valve is closed

[rangerslee]

I have noticed that both radiators in my living room will not work if the valve for the hot water tank is open. All other rads upstairs and downstairs are hot enough but hotter when the valve closes for the hot water. I suspect the valve is faulty and does not always close but how would this effect just 2 rads??

 

[ChrisR]

Could be that more water than necessary is going through the HW cyliner. Or that the pump isn't pumping fast enough - they are usually 3 speed

 

[rangerslee]

I have tried the pump at all 3 settings but it has made no difference. I will have a go at replacing the hot water valve anyway as it has occasionally stuck in the past and if this does not sort the problem I guess changing the pump is the only other alternative??

 

[oilman]

Try everything else before replacing the pump. Pumps do fail, but not as often as people think.

 

[rangerslee]

I think that the pump and the valve are working correctly. The problem seems to be that the hot water valve is not shutting down as the tank struggles to get to the 60 degrees that I have it set to. If I turn the tank thermostat down to 55 the valve closes. It seems to take nearly 2 hours for the hot water tank to be hot to the touch but the bottom third remains cool - is this normal??