Replace Potterton PRT100 with Honeywell CM927

[Sterd71]

Hi,

I'm after some advice with replacing a PRT100 thermostat.

We've recently moved into a new property that has the following setup:

Potterton Suprima boiler in kitchen
Potterton EP2002 programmer in kitchen
Potterton PRT100 thermostat in the living room

There's also a tank in a cupboard in the living room that is connected to a small white box that is marked Myson Power Extra, and another unit that is marked Myson Compact CP53.

The thermostat on the tank is set to 50 degrees.

I would like to replace the PRT100 with a wireless thermostat. I'm happy for the receiver to sit on the wall where the PRT100 is, but I would like to move the new thermo unit to the hallway where it is cooler.

The problem we have at the moment is the living room warms up quickly and switches the heating off to the rest of the house leaving the upstairs quite cold.

I've read that it is fairly simple to replace a PRT100 with a Honeywell CM907, but is it straightforward to replace the PRT100 with the wireless receiver from a CM927?

The PRT100 is wired up as:
Red --> 1 (TL)
Yellow --> 2 (H)
Blue --> 3 (N)

Thanks for any help,
Steve

 

[jackthom]

If the living room is heating too quickly I'm guessing it doesn't have a thermostatic radiator valve fitted. Even so you could experiment with closing down the lockshield valve so there's less hot water flowing through that radiator.

If you are going ahead with a new cm927 it should be very easy to wire the honeywell receiver where the old thermostat was.

On the Honeywell receiver with the boiler mains electrical supply safely isolated...

Blue (Neutral) will go to 'N'
Red (Live) will go to 'L'
Yellow(Switched Live) will go to 'B'

and a short wire link is required from the spare 'L' terminal to 'A'

http://www.honeywelluk.com/Documents/Installation-Guide/pdf/1069.pdf

 

[Scarum]

The problem we have at the moment is the living room warms up quickly and switches the heating off to the rest of the house leaving the upstairs quite cold.

Try balancing the sysyem first. I bet the lounge rad is the last on the flow. The upstair rads hog the heat leaving the lounge rad with a low flow.