My house was built 2002 with an oil fired boiler and has two heating
zones, one upstairs and one downstairs with a wall mounted thermostat
(in bedroom and livingroom) for each zone . There are no TRVs anywhere.
(I'm using a digital 3 channel programmer to time the 2 zones and the
hot water.)
Problem:
The thermostats work if I manually turn them up and down but they don't
seem sensitive enough to adjust with the rise and fall in temperature.
What I mean is if the temp is high and the heating on I turn the dial
down until it just clicks off. (say 21deg) Next morning when its
freezing cold the heating hasn't come on.
My thoughts are that it's because the stats only have two wires going
to them so the stat is only switching the live feed to the motorised
valve. There is no neutral wire to actually make the thermostat itself
work "properly". (not sure how to explain this technically)
Would a digital thermostat with a battery power source solve my problem
or am I missing the point?
I don't want to have to start tracking wall and rewiring.
Any advice?
thanks

AL