Understanding Thermostats

bpk101

Hi,

I’m currently having a new radiator system installed as part of a full refurb of my victorian mid-terrace, but understanding TRV’s and Thermostats and what to get and where to put them is causing me headaches… I need to move quick as builders are waiting! :mad:

We’re having 5 x Acova column rads installed and a new Worcester Greenstar 38CDi Combi Boiler. I understand with any new build or refurb, TRV’s need to be fitted as well as a Room Stat, is this correct?

Given the complications that arise when having a TRV in the same room as a Room Stat, is my plumber allowed to fit a standard manual valve on 1 of the radiators, or do all 5 rads need TRV’s to comply with building regs?

If the latter… should I buy a TRV for the 5th radiator and disable it once he’s signed the work off? The TRV’s we want aren’t cheap(!) and I rather not buy one then have to tamper with it.

We were also considering a ‘smart’ thermostat like the Wave, Tado, or Nest but I’ve read so many mixed reviews about them I’m not sure I’m quite ready to part with the cash. Should we just get a standard digital room stat installed for now? Again I need to make some pretty quick decisions.

My builder seems to think if we installed a smart stat, then we'd still need to install a wireless digital theromstat which i presume is incorrect?

Thanks!

phoenix_w

TRV's are required for new installs, but you shouldn't have a TRV in the same room as the thermostat. Of course, if you have a wireless themostat you need to adjust this to "you shouldn't have a TRV in the room you'll be in the most".

Can't answer your question on smart thermostats. If I had the spare cash I'd definitely get one just so it can turn on the heating at the optimal time based on weather forecasts, and the ability to learn our schedule which is complicated due to my other half's part time work situation. If you plump for a normal electronic thermostat, try and find a decent one that meets your needs by reviewing the user manuals online. In my last place we had a Siemens wired thermostat which was absolutely wonderful because of all the different override settings and a full 7 day planner. In my new abode we have a Honeywell wireless stat which is very bare bones - no individual settings for each day and very basic override options

bpk101

phoenix_w wrote: »

TRV's are required for new installs, but you shouldn't have a TRV in the same room as the thermostat

So are we allowed to install 1 radiator without a TRV? Or does building regs require all radiators have TRVs fitted on installation?

Our room stat will probably go in the dining room and not the living room as we're having a log burning stove installed there.

MX5huggy

You don't have to have a TRV in the room where the stat is fitted to the wall. As the stat provides the control of that rad.

If you have a wireless stat that you can move around then have TRV's on all rads and set the TRV in the room that he stat happens to be in to fully on (normally 5).

Is it bad form to quote yourself?

You have to have thermostat, programmer and TRVs unless your house is over 150m square (which is a big house) then you have to have zone control which splits the house in to 2 or more independently controlled zones each with its own programmer and thermostat.

I would do zone control anyway it means you don't heat the bedrooms all day to have it warm in the day rooms.

The thermostat (zoned or not) I would have as a programmable thermostat this means that you can set different temperatures for different times of day. So you can have 18 during the day and 14 at night without truning the dial.

Finally I would have weather compensation control which has an external sensor and turns the boiler up or down based on that. Saving gas.

bpk101

With regards to Thermostat, our builder has costed up the new boiler/rad system based on a wireless stat... if we decide to go for a 'smart' stat instead like the Worcester Wave, Tado or Nest... i presume this is instead of the wireless stat right?

Likewise if we opted for a hard-wired stat instead?

MX5huggy

bpk101 wrote: »

With regards to Thermostat, our builder has costed up the new boiler/rad system based on a wireless stat... if we decide to go for a 'smart' stat instead like the Worcester Wave, Tado or Nest... i presume this is instead of the wireless stat right?

Likewise if we opted for a hard-wired stat instead?

Yes you would only have one of those 3 options.

r2015

TRV’s need to be fitted as well as a Room Stat, is this correct?

Not according to one of the so called "heating engineer" I got a quote from.

Either or.

MX5huggy

r2015 wrote: »

Not according to one of the so called "heating engineer" I got a quote from.

Either or.

You have needed both on all new installs since at least 2006 it's in the domestic services compliance guide.

Zandoni

Generally, one radiator should be left without a TRV and left permanently switched on, unless the boiler is fitted with a flow meter to detect when all the radiator valves are closed. This special radiator may be a bathroom towel rail (where the heat is always likely to be useful), or in the same room as the room thermostat. It is not a good idea to have a TRV on the radiator in the same room as the main thermostat, as if it turns the radiator off at a lower temperature, it can mislead the main thermostat into thinking that the house is cooler than it really is.


Quote from http://www.nef.org.uk/knowledge-hub/view/thermostatic-radiator-control-valves

bpk101

Here's a floor plan of my supposed heating layout:

http://bpkersey.com/images/open-rooms-2.jpg

Radiators have been purchased (Acova Column Rads) and we're choosing valve types this weekend.

Room stat i'm thinking either the Tado or Worcester Wave (we're having a new Worcester Greenstar 38CDi Combi installed)... fitted in the dining room on the north facing wall.

Will this set up work well?

Zandoni

I'd put the non TRV radiator and thermostat in the lounge.