Wireless thermostat

[Oliver Maunder]

Hi all

On our central heating system, we've got a room thermostat. It's just a simple rotary dial. The problem is that it's in the bathroom, which is by far the warmest room in the house. This means that the thermostat needs to be turned up to 25+ degrees to make the rest of the house habitable.

The heating system has a digital timer for heating and hot water.

What I'd like to do is move the thermostat to a different room, then put a thermostatic valve on the bathroom radiator (all radiators currently have plain valves). I'm looking at using a wireless thermostat, because I'm in a Victorian house, and any new cabling jobs will be difficult and/or ugly.

So, a few questions: Will I just be able to connect a wireless thermostat in place of the current thermostat?

Some of the wireless thermostats are programmable. How would this interact with the current timer? Would I just put the heating on constant and let the thermostat deal with everything?

Can anyone recommend makes or models of thermostat to look out for?

Thanks for your help

Olly

[Matt]

You must have no thermostatic valve in the room you move the thermostat to.

Not quite, you will need a mains feed to the main unit location, but this could conceivably be anywhere as long as the remote unit is "seen"

Yes

Honeywell CM61RF (same every day programming) or CM67RF (7 day programming)

[burbeck]

hi olly bit odd putting the stat in the bathroom, they must have been short of cable. my recommendation is the honeywell CM67 RF, this is a programable thermostat, which in your case would be ideal. there is a control box that is put in place of the existing thermostat (only two wires to connect, easy ) and a battery opperated themostat which you put where you like. this unit is a little more expensive than most others but it has good features and is rugged and reliable. you are correct with regard to your current timer just set it on constant central heating and let the programable take over, if the existing timer also controls the hot water then leave that bit timed on the existing settings. hope that helps regards bob

[Dave Liquorice]

The receiver may well be able to fit where your current room stat is. Might need a slight wiring change to make the live feed permenantly live rather than through the current time switch. Neutral should already be there and the switched live to control the system.

That is one option, I mention providing a permenant live to the receiver beacuse that "feels the correct thing to do". Setting the CH timer to constant would have the same effect of course. What I have done here is to give the Rx permenant live to live off but fed the switch from a feed via the CH timer. Mainly because the system is rather noisey and would wake us up if it came on at 0300... By having a controlled fed to the switch it's easy to say when the system is really going to heat even if the stat want to.

I have a Danfoss TP75 (I think the model number may have changed slightly). Others will rave about the Honeywell CM67 but ISTR that more features where standard with the TP75 and the CM67. There are many programmable stats about now but I'd look for one with true 7 day programming and at least 6 set points/day.

[Set Square]

AIUI, the base station which does the switching, also needs a mains supply - so it's a bit more than 2 wires. As others have said, it doesn't need to be exactly where the existing stat is provided you can get at the wires somewhere else - maybe near the wiring centre if you have one - and provided the sensing bit is within radio range.

An alternative which the OP may like to consider is to use the non-RF version of the CM67 in conjunction with a remote sensor. It depends on where you want the sensor to be, and whether you can easily run a wire to it from the bathroom. If so, replace the existing stat with a CM67(straight swap, no extra mains supply needed), and have a pair of *thin* wires (phone cable will do) going to the sensor. The stat will then switch based on the temperature of the sensor location rather than that in the bathroom.

As others have said the radiator nearest to the sensor should *not* have a TRV on it.

[burbeck]

hi all yes that is correct the CM67 RF does require another wire ie neatral. i was thinking about the non RF version. hopefully the existing thermostat has three wires (not always the case) if so the neatral will be there in existing stat. the idea of leaving the existing timer permanantly set to constant heating is to avoid any changes to the wiring. i have found this model very reliable and rugged regards bob

[Oliver Maunder]

Thanks for all the responses.

I'll probably put the receiver inside the airing cupboard with the timer and wiring station - there's mains power to the heating controls, so it should be easy to power the receiver.

Not only is the thermostat in the bathroom (a strange place) but it's on the wall of the airing cupboard - so it probably picks up a fair bit of heat from that. I'm guessing it's laziness on the part of the installer, who didn't want to trail wires down to the living room. Now I CAN identify with that!

Olly

[Oliver Maunder]

I'll have a look at that - should be a lot easier to do a neat job with thin wire.

Not a problem - as yet, *none* of the radiators have TRVs

Olly