Replacing old Honeywell thermostat

[BGT]

I have an older type Honeywell thermostat like this

which I am trying to get off the wall. I have removed the screw in the side at the top right hand corner but cannot get the casing to move. What is the preferred method please?

 

[Hot&Cold]

The outer grey plastic cover will pull off,now the securing screw is loose.

Have to use thumb and fore fingers to apply pressure/squeeze just inside the 2 top and 2 bottom corners of the grey cover at the same time, this will disengage the retaining plastic lugs and it will pull/wiggle straight off.

 

[BGT]

Thanks Old&Bold. Took some pressure from my old arthritic fingers but managed to do it.

 

[BGT]

I guess the next question is obvious. I am planning to use a Honeywell CM907 programmable thermostat. The central heating system has a condensing boiler, hot water tank, pump, and an older Drayton programmer which does not allow you to time the heating and hot water separately. I plan to keep the water on continuous and use the twice per day times for the hot water, the CM907 will then control the temperature profile. There is just one diverter valve in the system.

Looking inside the old Honeywell thermostat it is wired as Red to terminal 1, Yellow to terminal 3 and Blue to terminal 2. What connections do I make in the CM907 please? Their installation instructions with wiring diagrams are here www.honeywelluk.com/Documents/Installation-Guide/pdf/1161.pdf

 

[Hot&Cold]

BGT

your next question is a New question and your better creating a new thread here or on other sites but consider how you will test any diy alterations that will satisfy your property insurance.

Not many people understand DiY and existing property insurance

TTFN

 

[Hasmo]

Hello guys please can I replace this kind of thermostat from honeywell to digital type I have searched for same couldn't find it's connected to package unit Tj 50-32 model please help