Thermostatic Radiator Valve Questions

[MacNala]

I am considering having radiator thermostatic valves fitted. I do not understand how they will work in the system I have.
Currently the heating system (gas) is a condensing boiler and a Hot water cylinder connected somehow and having a pump, a three way valve and a single wall thermostat switch. The whole system is controlled by a timer with separate controls for Hot Water and Heating.
If TRVs are fitted to all but the towel rails in bathrooms and kitchen I can understand how they will control the individual room temperatures.

My questions however
1 - Is the thermostat on the wall downstairs redundant?
2 - Does the pump need to be running all the time?

 

[ianniann]

Even with TRVs fitted you should still have a wall thermostat fitted. TRVs will only switch off (almost off) individual radiators, but the boiler will continue to operate. The wall thermostat will turn off the boiler, hopefully (adjust it!) after all the other rooms are also warm. It is worth mentioning that you should not have a TRV on the radiator in the room with the wall thermostat. You want this radiator to remain open until the wall thermostat shuts off the boiler. You may also leave the towel rail without a wall thermostat so that it is always warm, and since it puts out relatively little heat.

The pump should run so long as the wall thermostat asks for heat. And then a little longer called overrun.