new heating controls

[andyb123]

Hi all

Just after some advice. Ive currently got a honeywell ST799 programmer and a honeywell DT200 room stat and wanted to change it to a wireless system. Would the honeywell cm927 be the way to go?

Basically ive got a couple of rooms in the house that get very cold and the room where the roomstat is gets very hot. By having the wireless programmable roomstat id be able to put this in the colder rooms and also control when the hot water and heating come on and off?

cheers
andy

 

[Whitespirit66]

You would need to keep your old programmer to control the hw, but the new wireless stat can control ch temp and timings.

I think you need to look at why the rooms are too cold first. If you put the stat in these rooms with either malfunctioning or undersized rads, then set the stat to your preferred temp, then the rooms may still not get hot enough, but the rest of the house will be very hot. Do the rads in these rooms get hot enough? If not, perhaps your system just needs balancing. See the FAQs.

Check rad sizings here -

http://www.radcalcs.com/

 

[Steve]

If the room the thermostat is in gets very hot, you should lower the temperature on the stat.

If you wish, move the thermostat to the cooler rooms, and fit TRVs to the hot rooms so they shut off early.

And you will still need some timer for the hot water - this new stat wont provide this, it is only single channel, designed for heat only systems and combis.

Wireless stats are just a gimmick. Its a permenant item, to be fixed to a wall, whats wrong with running a cabel to it?

 

[hertsboilers]

I think you need balance your heating system first. Turn the hotest radiator valve fully closed, then open one or two turns, to get just required tempreture, then second hotest radiator etc.

These radiators are working like electric resistors in parallel, you need adjust them to roughly same resistances.

 

[ianblue]

Andy , what herts is telling you is quite correct.
The main fault to be addressed is why the big differential in room temperatures?
The radiators should all be sized according to the heat loss and room size.
In theory if this has been done correctly all rooms should achieve their correct temperature. http://www.homesupply.co.uk/radiator_output_calculator.php
Either the radiators are incorrectly sized or the system is needing balanced/unblocked/bled.
The thermostat is always best in the room where you are sitting of an evening. That's where you want comfortable control.
The wireless 'stat only does away with the cable and is very expensive.