I had central heating installed early this year, so comes with all the expected controls (TRVs on all rads except where the room stat is), 7 day separate CH and HW programmer, and a room stat. (It is a conventional rad CH and HWC system.) The room stat seems to be the thing that is letting down the whole system control. It is either on for long periods, or off for long periods, and seems to be very insensitive.
The room thermostat is a Danfoss RET230P (old style). It is positioned on a solid internal wall (first floor landing). The walls are usually colder than the air temperature and I think the positioning of the air vent of the thermostat (for want of a better term ) is too close to the wall so the thermostat is responding to wall temperature rather than air temperature. I'm on a very tight income so I have the heating on the minimum I can get away with, so getting the whole building fabric up to a nice temperature is not possible (all internal walls are solid, and groundfloors are concrete, so it is a slow response building), and very good control is essential.
I'm wondering what is best to replace it with. I had a Honeywell T6360B (or earlier model) in a previous house, which worked well, so am considering that. I notice from DIYnot's FAQs that some digital room thermostats are better, and had a quick look at the Honeywell DT90E, and like the specificatiion, but notice that it is a 2 wired thermostat, whereas mine is a 3 wired (not that I've checked inside yet...). Does that rule out the DT90E?
Also I'm wondering whether I should mount the thermostat on a timber pattress to reduce the cold wall effect.
I'd be very grateful for your advice/experience.
The room thermostat is a Danfoss RET230P (old style). It is positioned on a solid internal wall (first floor landing). The walls are usually colder than the air temperature and I think the positioning of the air vent of the thermostat (for want of a better term ) is too close to the wall so the thermostat is responding to wall temperature rather than air temperature. I'm on a very tight income so I have the heating on the minimum I can get away with, so getting the whole building fabric up to a nice temperature is not possible (all internal walls are solid, and groundfloors are concrete, so it is a slow response building), and very good control is essential.
I'm wondering what is best to replace it with. I had a Honeywell T6360B (or earlier model) in a previous house, which worked well, so am considering that. I notice from DIYnot's FAQs that some digital room thermostats are better, and had a quick look at the Honeywell DT90E, and like the specificatiion, but notice that it is a 2 wired thermostat, whereas mine is a 3 wired (not that I've checked inside yet...). Does that rule out the DT90E?
Also I'm wondering whether I should mount the thermostat on a timber pattress to reduce the cold wall effect.
I'd be very grateful for your advice/experience.