Where do I mount my thermostat?

[S1llyB1lly]

Hello folks

Right, here's the plan of my 1 bedroom, ground floor flat I'm refurbing. It is about 850sq ft in total.

http://i990.photobucket.com/albums/af24/superiorsounds/Rads_zpsd2kkflyz.jpg

In that image, rad positions are marked in red, going with decent rads, so something like Quinn or Myson I think.

I am not very knowledgeable when it comes to thermostats - so my initial question is where should I mount it? Is there any benefit to having one of those smart thermostats that I see talked about much on this forum? Would one thermostat cover the whole flat?

In terms of my boiler, it is a Potterton Promax Combi 28, with an output of around 28kW according to the manual.

Any advice appreciated as I'm sort of in the dark on this one.

Cheers.

SB

 

[stem]

Ideally a room thermostat should be located:

1. Not on an outside wall (probably would be OK for properties with very good wall insulation)

2. In a room without another heat source that may effect it (ie gas fire, kitchen, lots of electrical equipment etc.,)

3. Ideally not in a room subject to direct sunlight, or one that heats up quickly. A north facing shady room is best, so the other rooms heat up first and are controlled by their own TRV's before the thermostat turns off the heating system.

4. Away from draughts. (air bricks, windows etc.,)

5. In a room with a radiator (sounds silly I know, but I've seen thermostats in internal passages or hallways without radiators in. If the doors are closed the rest of the house is warm but the thermostat doesn't switch off because no heat reaches it)

6. In a room where the radiator(s) are not fitted with TRV's

7. 1.5 metres above floor level.

 

[S1llyB1lly]

Thank you very much for that!

Right, as you can see on the plan, it's quite a small flat, 850 sq ft all in.

With your criteria in mind, the only place I can really think of putting it is in the hall, outside bedroom 2.

That way, it won't be near a heat source, the little radiator in the hallway won't have a TRV, there are no windows, no direct sunlight and no equipment that can generate heat.

Other option is on the wall just where it states utility, but that will be next to a window (although that is a non-opening window).

Or do you advise elsewhere based on the plan below?

 

[stem]

It's a tricky one. you don't seem to have an ideal position. Internal hallways tend to stay warm and so the heating could stay off longer, whilst the surrounding room with external walls and windows would cool more quickly. The lounge is often a good position (if free of other heat sources such as a fire or wood burner etc.,) as this is usually where you want to be most comfortable, the problem is that yours is open to the kitchen which means that the thermostat would likely turn off the entire heating system when you were cooking. Maybe that would leave your bedrooms and bathroom cooler than you would like, maybe not, difficult to tell from a plan.

One possiblity may be the utility area on the wall between it and the bathroom. It's shielded from the kitchen area. But wouldn't be recommended if you have a tumble dryer there.

If you purchase a wireless thermostat, you could try it in the different positions before fixing it permanently, although that raises the TRV issue. Some see leaving a TRV on maximum in the room where the thermostat is located as an acceptable alternative to not having one installed. It's not ideal though because they could be turned down inadvertently by someone who doesn't understand the principles.

 

[S1llyB1lly]

Right, I just remembered that the boiler position has been omitted from the plan, annoyingly, I have corrected this, it will sit in a small cupboard, shown in orange, marked B.

Should I stick the thermostat in that case next to the non-opening double glazed window, in the corner, marked X? Only problem is that within the same room area, I will have rads and each will have a TRV

 

[stem]

Ha! where you have shown the boiler was the wall where I suggested the thermostat go. That area is probably not a good idea now, because the boiler will generate some additional heat.

Internal corners are not good either as air doesn't circulate too well.

Perhaps you should consider something like a Honeywell Evohome system. There isn't a single over-riding room thermostat but individual TRV's linked via wifi to a relay unit that turns the boiler off when everything is up to temperature. I personally have no experience of it though.

 

[S1llyB1lly]

Morning Stem! The Honeywell system is quite expensive by the time you take into account all the TRVs. The boiler will be in it's own little cupboard, walls will be made from 15mm SoundShield Plasterboard, and any gaps sealed with expanding foam.

With that in mind, do you still think there will be much heat generated which will interfere with the thermostat? It's that or the hallways unless you really say I shouldn't?

 

[stem]

Impossible to say really, it all depends on how much heat is retained / lost from the area where the thermostat is located, in comparison with the rest of the property. I would suggest that you get a wireless thermostat and try it in the different locations before fixing it to the wall. If you are worried about the TRV's, you could just remove the head from the one where the thermostat is located when you have decided on a final location.

Unfortunately with your layout, there are problems with all of the locations really.

1. The bedroom passage, is likely to retain heat because of it being internal, this could keep the heating off whilst the other rooms with external windows and doors cool down.

2. Utility area, fairly enclosed space and close proximity to the boiler.

3. Lounge area heated by cooking, hence keeping it warm and the heating off, so the bedrooms will cool. This may be your best bet now though. If the bedrooms don't cool too quickly when all the radiators go off, then once you have finished cooking and the room cools, the rads will come back on.

 

[S1llyB1lly]

Very logical, thank you for the explanation.

Honeywell is quite pricey, are there any other wireless thermostats you can recommend for me to go away and research?

 

[stem]

The Honeywell Evohome is more than a wireless thermostat, it provides overall zoned control, so that the need for a single overriding thermostat is removed. Handy when there isn't an ideal location for a room thermostat, but yes it does cost more.

Generally with 'standard' wireless thermostats you get what you pay for. Danfoss, Honeywell and Drayton have always been of a fairly good quality, and I believe that Horstmann have improved too recently. I've installed a few Salus units which are generally cheaper and probably for that reason have become quite common now. They are a bit tricky to master programming, but other than that, I've not had a problem with any, but some on here have had problems.

You may want to consider an intelligent one that is accessible via an app when you are away from home. I have only installed a Nest for someone else, so I can't comment on living with it day by day. There are lots of others available now, such as Hive, Heatmaster, Todo to name just a few.

Whichever unit you choose, always change the operating frequency from the factory setting when you install it, I have come across two instances where the thermostat in one property was switching the heating next door.