thermostatic valves on all radiators.

[jobloggs]

Hi

My OF heating system has one pump. This is on the return inlet at the bottom of the boiler through which both the CH and the hot water circuits are returned. (Is this usual? I suppose it keeps the pump slightly cooler)

I have fitted thermostatic valves on all my radiators except for two. Would it be OK to fit these radiators with thermostatic valves as well relying on the hot water circuit to ensure an open circuit for the pump?

Thanks in anticipation.

 

[ChrisR]

(Is this usual? I suppose it keeps the pump slightly cooler)

Used to be common because of the cooler running. Now frowned upon because of the possibility of negative pressures getting air into the system through micro-leaks.

You must not rely on the cylinder for a bypass - add a separate one if you need one. NB 3 port valves will stay on the ch position when the thermostat goes happy so there might be NO path for water.

 

[jobloggs]

Thanks ChrisR

System has very little control. No room or cylinder thermostats and no motorised valves of any description. CH and Hot water cannot be operated independently. Would thermostatic valves on all radiators still be inadvisable.