Upgrading from Analogue to Digital Thermostat

[Dee_in_London]

This is the Thermostat in my parent's mid-terrace house that they've lived in for over 40 years. My father probably fitted it himself as he used to be a plumber but now he's in his 80's with Dementia so if I ask him anything he doesn't remember much. The house is heated with a gas boiler and radiators.

I was wondering how easy it would be for me to change this for a very Simple Digital Thermostat - with nothing more complicate then a simple Boost button.

What Model Thermostat would people recommend replacing it with?

My parents are not technical at all - so don't want anything fancy - just a very easy to read Digital Display and a simple Boost button so if the house is feeling cold they can push the button and maybe the heating turns on for 2 or 3 hours.

Also just by looking at the photos is it possible to tell what the different wires are for? I read something about modern Digital Thermostats only needing 2 wires?

BTW how long do the batteries tend to last in a Digital Thermostat as that's something I'd have to schedule into changing. As my parents wouldn't change batteries themselves.

Thanks in advance.

 

[stem]

I think you are getting your devices confused.

This is a room thermostat, it switches the heating 'on' when it is below the set temperature and 'off' when it reaches the set temperature. The on/off time control that would include the boost control is a different piece of equipment.

There should be a programmer that is used to set the times that the heating is switched on & off somewhere.

Also just by looking at the photos is it possible to tell what the different wires are for?

There should be a diagram on the inside of the cover that shows what the wires are for. Something like this:

 

[Dee_in_London]

I could well be getting my terms mixed up - what is the Green Eco Button for on the Honeywell DT90E1012 do then?
I thought it was a way to turn on your heating on days when you feel extra cold?

 

[Dee_in_London]

BTW will a 2 wire Thermostats like the Honeywell DT90E1012 work with this kind of system?

 

[stem]

I know Honeywell DT90E Can't say I have seen a Honeywell DT90E1012. But yes, a 2 wire thermostat can replace the old Honeywell. The neutral wire which is not required is simply isolated/insulated and tucked out of the way.

what is the Green Eco Button for on the Honeywell DT90E1012 do then? I thought it was a way to turn on your heating on days when you feel extra cold

No, just the opposite, it lowers the temperature set on the thermostat for a few hours to save energy. So if you normally have the temperature set to 20 degrees the Green Eco Button will drop the temperature to a lower setting eg 18 degrees for a few hours.

 

[Dee_in_London]

OK Thanks - I won a new Digital Honeywell Thermostat on eBay so waiting for it to arrive ...
Any ideas how long the batteries tend to last in these devices?

 

[ianmcd]

They advertise 2 years but all depends on what batteries you use, dont use cheap rubbish

 

[Mottie]

I know Honeywell DT90E Can't say I have seen a Honeywell DT90E1012. But yes, a 2 wire thermostat can replace the old Honeywell. The neutral wire which is not required is simply isolated/insulated and tucked out of the way.


No, just the opposite, it lowers the temperature set on the thermostat for a few hours to save energy. So if you normally have the temperature set to 20 degrees the Green Eco Button will drop the temperature to a lower setting eg 18 degrees for a few hours.

I have a DT90E and you can preset the Green eco button to whatever temperature you like. I normally have my temperature set at 21.5°-22.0° but I have my eco button set at 23° to boost the heating if it’s getting a bit cold for 1,2 or 3 hours. It will tell you when the batteries need changing, I think my first set lasted 3 years.

 

[stem]

Ah OK thanks for the clarification I have only seen it used the other way, to drop the temperature for a couple of hours when you go out to save energy & whilst the house is empty. To call it an Eco /Green button would seem a bit of a misnomer if it can be also used to increase the energy consumption by turning up the heat.

The heating programmer / timeswitch will also have to be set to have the heating 'on' for the Eco? function to operate. However most programmers tend to have a Boost button that puts the heating 'on' for an hour outside of the programmed time settings. This is what I thought was being referred to by 'boost' in the first post. Apologies for my confusion.