Are separate thermostats/zones (upstairs & downstairs) actually inefficient.

[Jreid1611]

Hi ,

I have just moved into a new build property which has a thermostat downstairs lobby (zone1) and a thermostat upstairs lobby (zone2). However, I have my doubts whether this is actually energy efficient and believe it may be actually costing me money.

In order for the upstairs bedroom to be warm going to bed the upstairs stat has to be up high since that area of house is very warm later on at night. But due to this stat being up high it means boiler is constantly running until this temp is met.

I believe it would be much more economical to only have 1 stat, which would cause the boiler to cycle on/off as normal.

Has anyway else got any experience of this or can explain and confirm 2 zone thermostat system is actually economical?

Thanks

 

[Ray Stafford]

Hi Jreid.

Generally speaking, having separate time and temperature controls for zones that your lifestyle uses differently (for example, the upstairs and downstairs of a house) make a system more efficient. Indeed, they are required in properties of 150m2 or greater if my memory serves.

I'm wondering from your post if your zones are timed separately, or are they timed together, but with separate stats?

 

[lame plumber]

Nope....














but if your trying to heat up rooms to temps of 20 plus then that is pretty inefficient, try setting your rooms at 18 on trvs and rm stat, probably find the boiler wont come on as it is warm enough already.

 

[Unregistered]

Hi, thanks for the replys.

Ray, I only have 1 timer but 2 stats.

Lame, if I set both stats at 20 by the time I go to bed the upstairs bedrooms are cold. I touch the radiators and they are stone cold - not been on for hours. Obviously the upstairs stat is in a warmer part of the house and as the house heats up (say from 20:00 onwards) the upstairs stat is permanently satisfied it is seeing 20degc and so does not request for heat to the radiators upstairs. Downstairs stat cycles the boiler off/on as the temp cools down but the temp upstairs does not drop.

 

[Worcester]

Lame, if I set both stats at 20 by the time I go to bed the upstairs bedrooms are cold. I touch the radiators and they are stone cold - not been on for hours. Obviously the upstairs stat is in a warmer part of the house and as the house heats up (say from 20:00 onwards) the upstairs stat is permanently satisfied it is seeing 20degc and so does not request for heat to the radiators upstairs. Downstairs stat cycles the boiler off/on as the temp cools down but the temp upstairs does not drop.

It is more efficient to have two stats, one up one down.

You need to set up the thermostatic radiator valves (TRV's), lockshields and room stats to balance the system for heat.

The principle is that based on the heat load for each particular room, they are satisfied for heat at the same time that the stat is.

If you don't know how to balance it all, get a heating engineer (not plumber) in.

You can also further improve the efficiency of the system by converting the upstairs stat to a time controlled one - usually a simple retrofit, so that you can have seperate time zones for up and down.

Even better you can get ones that allow you to set different temperatures at different times of day (sometimes called 'Comfort levels') You may be suprised to learn that in most circumstances it is generally more efficient to set back temperatures when areas are not used than turn them off fully.

This way you can tune upstairs and downstairs temperatures to suit your usage patterns.

What make and model time controller and stats do you have, wired or wireless?

 

[GSAL]

Sounds like you need to move your upstairs stat into your bedroom?

 

[acecharly]

Hi, thanks for the replys.

Ray, I only have 1 timer but 2 stats.

Lame, if I set both stats at 20 by the time I go to bed the upstairs bedrooms are cold. I touch the radiators and they are stone cold - not been on for hours. Obviously the upstairs stat is in a warmer part of the house and as the house heats up (say from 20:00 onwards) the upstairs stat is permanently satisfied it is seeing 20degc and so does not request for heat to the radiators upstairs. Downstairs stat cycles the boiler off/on as the temp cools down but the temp upstairs does not drop.

You say its cold when you go to bed but you set both stats to 20 and upstairs is the warmest part of the house surely if its warm downstairs heat rises and upstairs will be as warm if not warmer.

Do you keep all the doors upstairs closed? so its heating downstairs and basically the stairs and landing? If so the heat from downstairs will warm the upstairs stat but not the bedrooms.

 

[Best]

As above 2 posts say ^^ it sounds like your upstairs stat needs in main bedroom. That way, if upstairs rads are correctly evenly sized then all bedrooms will be at proper heat

 

[acecharly]

Another possibility is to set zone 2 to come on an hour before you go to bed and set the upstairs stat to 30.
This is also dependant on the fact that it is definately upstairs / downstairs zoned and not room specific which although unlikely you can check by running one zone and going round and checking how your place is piped.