Honeywell DT90 and timer and Eco function - working together

[craynerd]

Hi guys
I'm about to have a new dt90 wireless thermostat fitted to my new boiler. I'm at a bit of a loss as to how both the thermostat, Eco mode and boiler timer work together! I'm sure a few days of fiddling and I'd work it out but would appreciate any advice or info to save time.

Basically, I have a standard timer on the boiler so you can set the boiler to come on or off at certain times of the day, on all the time or off all the time. I'm confused how the honeywell links into this. If I have the thermostat set to 22deg for example, and the timer is off/heating off - will the boiler stay off regardless of the temperature? If I have it set on timer, I presume it'll just come on IF the timer is set to on AND the temp is below the desired range?

So I presume it is best to set the timer just like I use to but can be a little less tight and allow it on for longer as it won't heat unless needed. Currently, if I turn the heating on for a period, it is on all that time regardless of temp - the thermo valves on the radiator are usless.

If what I said above is all correct, - why would you use the Eco mode? I believe this is a default mode of 18deg C temp set and is a timer - you set it to how long you want to keep it to 18deg before it reverts back to the main temp setting. I don't see why this would be useful, surely just turn the main temp down to 18 deg or change the timer settings on the boiler?

Chris

 

[Dan Robinson]

The thermostat is a slave to the time on the boiler.

Eco mode is there to temporarily lower the thermostat's setpoint .

It is still a slave to the timer.

How useful is it?

Lord knows.

I have 6 of these in my house and never use the Eco buttons.


If your timer is off the thermostat does nothing.

If your timer is on the thermostat controls the boiler according to the temperature you have chosen.

Eco lowers that temperature for the period of time you chose, say for going out to the shops.