Hi all, I have an antiquated central heating system, normal boiler, hot water tank etc. My room stat seems to of stopped working & I would like to replace the controls in the airing cupboard at the same time, my current stat seems to have three wires but no earth.

Any idea of a decent replacement set up that would suit?

Cheers in advance.

Id look at a CM927 by honeywell.

Makes all the wires redundant as it’s wireless. Gives you the flexibility to move the thermostat/programmer anywhere.

The relay is connected to the boiler as a circuit switch as appropriate. I guess it depends on how the existing stat is wired into the boiler.

EDIT – you also would need to consider how the boiler manages timing though. Unless you tried to find just a simple on/off room stat and leave the tmie control to the boiler. However if you can set the boiler to have no time control on the CH and leave that to the stat then that is handy.
http://www.honeywelluk.com/products/Temperature-Controls/Temperature-TPI-Control/DT92E/

As abive, used one for years, fantastic bit of kit

CMT927 DOESN’T control hot water. If your current system/controller does heating & hot water, then I wouldn’t go for that controller, unless you can wire up a separate single channel controller to take over hot water control duties….

I’ve just been through all this at home, after originally buying the CMT927 and having to take it back.

I went for this instead
http://www.honeywelluk.com/products/Systems/Wireless-Enabled/Sundial-RF2-Pack-2/
which is a heating/hot water controller that is wired into your boiler & uses the wireless thermostat that Stoner links to above.

Pleased with it so far….

I have the 907, which is the non-wireless version. It is a two wire, don’t think it needs the earth.

My hot water just stays on all the time now, but the tank is well insulated so I think the difference will be neglible. The house on the other hand, the temperature is much more stable with the new unit. With the old thermostat it yoyo’d between hot and cold.

I have a British Gas UP2 that the CM907 is working through, I will have to see if I can completely isolate the heating side of it as then I can just use the hot water side, and the 907 for heating.

Many thanks for the above chaps, most helpful.
I’m not bothered about wireless as the wiring is already there, I would just change the stat but the old timer in the airing cupboard frequently get knocked when putting the washing in so I would quite like a digital one.

Thanks again.

In that case – I’d go for something like this:

http://www.honeywelluk.com/Products/Time-Controls/Wired/ST9400C/

it’s the same controller as the one we’ve got without the wireless gubbins in it.

Dead easy to set up with 3 on/off times, plus things like ‘holiday mode’ and optimum start that ‘learns’ how long your house takes to warm up and adjusts the on/off times so the set-point is reached at the time you want (you don’t have the set the clock early so it’s warm when you get up)…

You can probably get a cheaper equivalent to be honest, but this does seem like a good product.

Thanks again, I have bought a ST9400c along with a DT90e stat, all is well apart from when I connect the stat the whole systems shorts, it’s fine with the old stat though so it’s not the controller 🙁
Anyway from what I have read I just need to take out the neutral wire to prevent this, but will this be ok for a Y type system, or is it suck it & see time?

Cheers.