Room thermostat question.

[greasedmonkey]

Bit of background first, Question at the end if you don't want the story...

We bought this house at the start of last summer, was built in the 80's and I think still had the original boiler which the previous owner had serviced by BG annually. due to the age of the thing, and a wife that was 7 months pregnant at the time, the first thing I did was fit a carbon monoxide alarm on the landing and some of those card things by the boiler where the spot changes colour. Anyhow, about a week after we had moved in, the pilot light went out and when I went to re-light it, the spot had turned black. Not wanting to take any chances we had someone in to look at the boiler, they were not impressed with what they found and he started to tell me what it needed. I didn't even let him get to the end of his list before I told him to just disconnect the thing from the gas and make safe. Which he did without further comment. I then pulled out the boiler, water cylinder and a whole rats nest of pipework. Money was VERY tight at the time (having just bought the house) so I got a cheap combi boiler (Ideal heating 38KW) and fitted it myself. (Before anyone shouts, I did everything apart from the gas. Got a gas safe registered man in to do that bit and commission the system) Anyhow, the boiler came with built in timer and thermostat, but not a room stat as I thought. So I re-wired in the old dial type stat in the hallway, which is now proving to be problematic, so I am off to get a programmer from screwfix at lunch time today.

So, the questions. :

1- Why does the room stat always seem to be fitted in the hallway? we are never in the hallway so don't much care what the temperature is out there. Does it not make more sense to fit the stat in the living room, or kitchen as these are the most used rooms in the house.

2- Am I OK to fit the stat myself as I wont be messing with anything to do with the gas or burny bits of the system, or do I need to get it signed off by the gas safe man as it does mean opening up the front cover of the boiler.

Thanks in advance.

 

[Dan Robinson]

1

For the convenience of the lazy installer.

2

Yes if you know that you are doing. Get a Honeywell cm927.

 

[greasedmonkey]

1

Yes if you know that you are doing. Get a Honeywell cm927.

I consider myself a competent person, but don't take any chances when it comes to gas. My family is precious and I wouldn't want them to be exploded. The guy that did the final gas fitting and commissioning of the system complemented me on the install and how neat it was. I did practise the soldering on a few bits of pipe that I took out first just in case.

I am looking for a combined stat / programmer thing that is not too easy to use so hopefully it will discourage the wife from constantly creeping up the temperature. (also dependant on what screwfix have as that is a 2 minute walk from the lab I work in).

 

[Dan Robinson]

The Honeywell has the ability to adjust the temperature offset. So you can make it report a higher temperature than is true. Handy for cold blooded wives.

 

[greasedmonkey]

The Honeywell has the ability to adjust the temperature offset. So you can make it report a higher temperature than is true. Handy for cold blooded wives.

Ooooh, This function I like !!!!!!!

 

[Galoka]

1

Yes if you know that you are doing. Get a Honeywell cm927.

I consider myself a competent person, but don't take any chances when it comes to gas. My family is precious and I wouldn't want them to be exploded. The guy that did the final gas fitting and commissioning of the system complemented me on the install and how neat it was. I did practise the soldering on a few bits of pipe that I took out first just in case.

Your aren't touching the gas, just connecting up a few wires. The worst that will happen is that the boiler will not turn on at the right times or whatever. Though if the old room stat is a basic dial one you may well need to run a new cable.

Re positioning of the stat, lots of people I know have the stat in the lounge. The best place for particular house will vary, depending on the system, the house, the aspect, how people use the house. etc. Ours is in the hallway and it works well there. It's a victorian house, still a bit drafty, with the landing a big area to heat, with 3 external doorways into the hallway and a big area of single glazing. So that is a naturally cooler area anyway.

All the other rooms have TRV's, it normally works that they all get to temp before the hallway. so the stat is set so that when the hallway gets to whatever temp, then the rest of the system is likely to be satisfied anyway..

And yes i know it means the system isn't really properly balanced, but I've never managed to really get it too balance properly. It's just such an old system, with some interesting pipe routings, it's just won't behave

 

[Dan Robinson]

The worst that can happen is a £200 pcb gets fried, but who's counting?

 

[greasedmonkey]

The Honeywell has the ability to adjust the temperature offset. So you can make it report a higher temperature than is true. Handy for cold blooded wives.

Handy, yes, but not worth the 80 quid difference in the price between that and the one I ended up going for.

The dial stat I currently have is a 3 wire jobby (plus earth) Live, switched live and neutral. The one I have got is a 2 wire jobby requiring just the live and switched live. Powered by a couple of good old AA batteries. I can easily disconnect the neutral from the boiler end.

I think I will leave it in the hallway as the wiring is already there and this makes it a nice easy 20 minute job.

 

[Dan Robinson]

Don't know what you ended up with. But your bottom line figure might actually be half way up the ledger in reality.

A decent controller can pay for itself quite quickly.

 

[kbdiy]

AFAIK the main reason for siting a stat in the hallway or some other 'neutral' area is so that it is not affected by drastic changes in heat.

For example, if you site the stat in the lounge, which may be occupied by several people, the heat requirement will be counteracted by the natural body heat of the occupants and the stat will register as 'satisfied'. This immediately affects the rest of the house which goes cold. Same applies to fitting the stat in the kitchen. You start cooking, the room temp rises, stat registers 'satisfied' and bingo, the rest of the house is cold. By keeping the stat central and neutral it will be less affected by sudden spikes and keep the house at an even temp.

 

[Dan Robinson]

So a front door opening doesn't lead to a sudden influx of cold air in the winter ?

 

[kbdiy]

Yes of course it does and that's why the best position is sited centrally away from the door (unlike some new-builds I saw recently where it was literally just inside the front door). However the effect is only likely to be short-term whereas the heat build-up in a lounge or kitchen is more likely to affect the stat over a longer period (imagine all gathered round the tele on Christmas Day for example). And of course some people like to add a roaring fire or just a decorative fire which will only add to the temp imbalance across the whole house.

 

[greasedmonkey]

Don't know what you ended up with. But your bottom line figure might actually be half way up the ledger in reality.

A decent controller can pay for itself quite quickly.

Got one of these

http://m.screwfix.com/p/horstmann-centaurstat-7-room-thermostat/12157

Mainly because of the good reviews and it looks simple to install.