by bobtb007 »
Tue Mar 06, 2012 5:17 pm
HI Pommy
Control options
Do you have thermostatic rad valves on all of your radiators?
If so that (in theory) regulates the temperature within each room, so technically there is no need for a room thermostat to control the boiler or pump.
BTW, normally a room stat sends a signal for the pump to run which will then circulate water around the entire house, when the stat is satisfied, the pump switches of, however, under gravity circulation, you may still have the radiators upstairs getting hot/warm.
it is good that you have two stats on the boiler. one for heating and one for hot water. This means that you can set the heating temperature as low as possible to take full advantage of the boiler condensing mode (this means the boiler will fire at its most efficient), the lower the temperature the more efficient the boiler will run (down to about 50degC), this however has a knock on effect of reducing the output from the radiators so still have it so that the rooms are a comfortable temperature and that changes with outside temperature conditions! That is why having an optimised start stop automatic flow temperature control is the best but is normally not fitted to domestic systems on the ground of cost.
Hope this help
Russ