Wall Thermostat Question

Gadgee

I live in the North of Scotland and have an oil fired combi boiler with thermostats on all the rads in the house but no wall thermostat. When first installed, I was assured that this arrangement was the most cost effective way of running the heating. My better half however is convinced that fitting a wall thermostat in the hall will reduce running costs and we are now waiting for an electrician to give us a quote to fit one.

I am trying to get my head round the mechanics of the wall mounted job and work out if the possible savings will give me a decent payback because of the design of the house.

The received wisdom is that the wall job be placed in the hall but given our hall is large and with an open staircase to the first floor, I can't see where the savings will come from. The rad at the back of the hall pumps out heat which simply rises through the open staircase treads and whilst it heats the top landing it has little effect on the rest of the hall downstairs. As far as I can see, if the wall job were to be mounted on a wall in the front of the hall then it would always be calling for heat. If it were to be placed at the top of the stairs then it would it would get up to temperature fairly quickly and not recognise that the hall was significantly cooler.

I appreciate that much will depend on the quote to install a wall job but would be grateful if somebody could give a view as to the benefits of the proposed wall job.

black-saturn

I've got a plumber in my house as we speak and he says you will have to set the thermostat lower to allow for it being in a cold environment and then you should save money on your gas bill.

Gadgee

How else could you get an answer from a plumber with 5 minutes (and for free)!!

Many thanks

Zebedee69

The plumber is speaking out of his !!!!

You already have every radiator with its own thermostat. Which is 100% better than a single thermo in the center of the house. So the guy who did the first install was spot on. The plumber you have had look at the system just wants extra work!

My advice.... Set each thermo in each room to Number 3 and see how you like the heat. If you can live with each rad on 2.5 then thats realy money saving. If there are any rooms that you never use then leave the rad on 1 just to provide relief from frosty weather and close the door.

So save yourself the hassle of getting the thermostat!!! You allready have a thermo for each room in your house!!! How many do you want/need!!!

Gadgee

Zebedee69 - I agree with you but I hope the plumber has left the house!!

Be interesting to see what other opinions come in as I will need a lot more like yours under my belt before I try to persuade herself that the current arrangement is best....

Tallymanjohn

We've just had our heating system updated - new boiler etc. & every quote we had (7 in all including BG & Powergen) stipulated a room thermostat together with TRVs on every radiator (older systems required one rad to not have one, but new boilers need them on every one). It was described to me that if you only have the TRVs, especially if you have one cold spot in the house, the boiler/pump will never switch off except by the timer - with a room thermostat, the hall (where it's situated) gets to 20deg & the boiler switches off - each room is regulated using the TRVs to get whatever temp. you want in each area. Previously we only had the TRVs, as mentioned & our heating bills were astronomical - keeping track now & our bills are nearly 60% of what they were, plus the house is definitely warmer overall! Would recommend getting a programmable thermostat so you can set daytime/nightime/out at work room temps.

A quick google brought up loads of stuff about this subject - here's an example: http://www.est.org.uk/myhome/efficientproducts/boilers/controls/

Cardew

Gadgee wrote:

Zebedee69 - I agree with you but I hope the plumber has left the house!!

Be interesting to see what other opinions come in as I will need a lot more like yours under my belt before I try to persuade herself that the current arrangement is best....

Well another opinion!

Zebedee69 is absolutely correct!

Why on earth would you want a thermostat in one location controlling the temperature in other rooms, when you have the ability to control each room temperature independantly?

Gadgee

Thanks Cardew..

Although my simple mind can cope with the sense of individual TRV's, Tallymanjohn's views and his 60% saving makes a strong case.

There again, it could be that his previous CH system was not in its prime and less than efficient so that the 60% saving could have been achieved with TRV's only in the new regime.

Tallymanjohn

Yes, I stick by my experiences & the logic as described to me. Have you looked at the Energy Saving Trust website link? - there's a load more in a similar vein stating the same requirements for economy.

The actual thermostats themselves range in price from under £10 for a basic control to around £40 for a programmable one. Fitting is obviously dependant on each situation but it isn't a major job - 3 or 4 wires linked into the existing programmer - there are even wireless ones available so no holes need drilling.

ollyk

Zebedee69 wrote:

The plumber is speaking out of his !!!!

You already have every radiator with its own thermostat. Which is 100% better than a single thermo in the center of the house. So the guy who did the first install was spot on. The plumber you have had look at the system just wants extra work!

My advice.... Set each thermo in each room to Number 3 and see how you like the heat. If you can live with each rad on 2.5 then thats realy money saving. If there are any rooms that you never use then leave the rad on 1 just to provide relief from frosty weather and close the door.

So save yourself the hassle of getting the thermostat!!! You allready have a thermo for each room in your house!!! How many do you want/need!!!

I think you are talking out of your !!!

Generally speaking thermostic valves should be considered as an extra energy saving device on top of a wall mounted thermostat in my opinion.
Trouble with just having TRV's, is that you are regulating house temperature by monitoring the temperature of heating water returning to the boiler, not by directly monitoring the air temperature.
Your house temperature could be at a desirable level but your boiler might still be waiting to see the return temperature reach the cut off point. This is a silly way to regulate heating on it's own! Turn the boiler down to compensate and some rooms might not even get up to temperature!
Also TRV's aren't exactly placed in the best position to monitor ambient room temperature - low down, right next to the heat producing source, altered by other parties and easily covered / obscured of decent air flow
TRV's are secondary to a thermostat in my opinion!
Now as for thermostat placement, I would recomend getting a heating eng. in who will be able to advise on the best possible location, normally the hall or lounge but I am not a heating eng. so would be guessing if I said for sure!
I will say it isn't a huge job to do yourself if you have boiler manual (don't worry it isn't a corgi job) but then I probably wouldn't recomend this.
Hope you get it sorted.

Tallymanjohn

It also saves the pump going all day, if you are one of the 24/7 brigade who thinks it saves money.

That's why the programmable ones are a good idea - you can set it at normal temp when you're in the house but at night & when you're at work, you set it to only come on if temp goes below 10degrees or whatever.