Replacement Room Thermostat

[alex_rsa]

Hi all,

We have recently moved house and have gone from a combi boiling in a well insulated house to a traditional vented central heating system in a poorly insulated house.

I started off using the timer on the boiler to have the central heating on for 6 hours twice a day with the room thermostat set to 19C. The recent cold temperature means the house is taking too long to heat back up again.

Yesterday I decided to leave the central heating on all the time and use the room thermostat to control things. We turned the thermostat down at night but again took to long to heat up again this morning.

The room thermostat is an old Honeywell rotary dial model with 3 wires inside. Can I replace the room thermostat with a modern digital version and expect it to control the temperature more acurately and leave the boiler on all the time? What we want is it to keep the temperature at 20C during the day and drop to 15C at night but have it back to 20C by 06h30.

Thanks

Alex

[MJG280]

One of the wires is the power to the thermostat and that needs cutting off. I have a Salus Model RT500 programmable stat. It allows 5 daily settings for the working week and 5 daily settings for the weekend. The cheaper ones often have 1 or 2 daily settings for the weekend. It is the clearest and easiest one that I have found. Buy it on the internet as much cheaper.

[Ricky_M]

A Honeywell CMT907 (hardwired) or CMT927 (wireless) would be ideal for what you need.

They are both Programmable Room Thermostats. The 907 can replace your old rotary stat.

The 927 can be used like a remote control, but you will need to wire the reciever into the mains and the boiler.

[Festive Ferg]

MJG280 said:

One of the wires is the power to the thermostat and that needs cutting off.

Eh???



The current thermostat will have a Live in and a Live out plus a neutral. You can terminate the neutral and simply switch the other two wires using the new thermostat.

It's unlikely to make much difference really though. You need insulation.

[dugsud]

Festive Ferg said:

It's unlikely to make much difference really though. You need insulation.

I agree, the thermostat thing is probably a bit of a red herring! Heating a badly insulated house is like pouring liquid into a colender, it takes a long time to fill as 75% of what goes in is leaking out as you do it!

It'll also cool down fast.

[alex_rsa]

I know insulation is the permenent solution but that will have to wait behind all the other tasks..till summer ironically.

I am basically looking for a single solution combining the room thermostat with the programming of the boiler to get me through a couple of months.

What would be a direct replacement for the Honeywell that would provide the features? It will be only temporary the replacement of the whole boiler is the long term planning.

Thanks

Alex