[?] Central heating system - where best to position the room sensor

[David Chapman]

Hello all,

Our updated central heating system now has a wireless programmable room thermostat.

I've seen a lot of wall-mounted thermostats in hallways (which is usually unoccupied, of course) and others in the living room areas. Now we have the flexibility to move it from room to room I'd be interested in hearing what others have to say about the most suitable (permanent ?) location for it. The only information I have found so far is about where it should NOT be located [draughty areas, over radiators or other heat sources etc.].

TIA - Dave

[mick]

I would suggest that you put it in a well used living area (after all, that's where you want the heat most of the time!) and turn any TRVs in there up to full heat. The system will then keep that area correct and the rest of the house can use TRVs where necessary. As the main radiator (s) will always have full flow, any flow-return bypass valve should be closed when using this system.

Ideally the stat should be on a North wall (you don't want sun to warm it up) but otherwise located as you say.

[Dave Liquorice]

I should hope those raditors don't have "full flow" and that the system has been properly balanced. If the TRV heads have not been removed I'd leave the bypass in place, just in case someone shuts those rad down. Such a bypass valve should be pressure operated one anyway.

Er, on a north wall the chances are the midday sun (due south) will shine it at least at some point in the year.

[Andrew Gabriel]

I experimented a bit when I was installing heating. Another particularly bad place to put it which is not so obvious is on the opposite wall facing a radiator. Hot air from the radiator goes up, across the ceiling, and down the face of the thermostat, causing premature switchoff. So a wall which is perpendicular to any radiator, or if on a facing wall, well away from directly facing the radiator work well.

Drafts are not much of a problem IME, unless the draft is a temperature which is unrepresentative of the house temperature, e.g. coming from an unheated area. The best positions I selected in two installations is in the living room near the light switch, which makes it potentially drafty, but like I said, it's not been an issue.

[mick]

Through windows, yes, but it won't be heated from the rear by the wall receiving direct sun and warming up. Personally I prefer an interior wall if it is possible to find a suitable one.

[Dave Liquorice]

If the wall is so thin and thermally conductive that it affects a thermostat attached to it I think there are bigger problems to worry about...