Radiator Thermostat Advice

KS2

I have installed 2 wire thermostats to replace my Danfoss ones, essentially 1 upstairs and 1 downstairs.

I have a number of rooms with 2 radiators in each but none of them have the wired thermostats in them. I initially bought a smart thermostat for each radiator but as I set them up making 1 of them the main temperature sensor, I'm wondering if I shouldn't leave the 2nd radiator in each area with a traditional radiator thermostat ?

Any thoughts would be welcomed.

policywonk

The smart thermostats being installed are more effective in saving money than normal trvs except in one place, a bathroom. That's the evidence I've seen in three homes since 2016.

KS2

Thanks policy work. Do you think it's saved enough at a radiator level to cover the cost of the smart thermostats ?

policywonk

Over 3-5 years in my eperience, yes. In my first home it paid for itself in two years with five rads. But only because we bought them on special deals, sometime on A****** or S******.

wateroakley

@KS2 Agreeing with the good advice from @policywonk

For a 4-bed detached 1960s home … we took the plunge in February 2022 with a wireless starter kit and 12 TRVs. The conservatory still has a dumb TRV as it's outside the range of the internet dongle. It took three months to figure out what worked well for us. ROI was about 9 months with expensive energy prices in 2022. We've since added another TRV and wireless temperature sensors to improve the comfort settings in three rooms.

We adjust the schedules to suit our diaries. The 'north wing' (office) is heated in the morning and afternoon, the'south wing' (lounge) in the evening, and bedrooms early morning and late evening, We use geo-fencing a lot. Rooms are mostly 18 deg C and 'OFF' when not in use. That stops us wasting energy to heat the home unneccessarily. When we have visitors it's easy to turn up the temperature in particular rooms.

Comparing gas consumption from 2018-21 (programmer, room stat and dumb TRVs) with Tado from February 2022 … at the same outside temperature (CET), annual gas consumption for 2022 = 75%. 2023 = 48%. 2024 (forecast) = 46%. Smart controls contribute to reducing our annual gas bill by £1,000. Battery life has been pretty good too.

Our rellie with a young family uses Tado in their Edwardian London villa. With smart TRVs in every room, the thermostat wars have stopped.

There is more opportunity for saving energy in 'larger' homes and the National Energy Efficiency Data-Framework (NEED) data confirms this. I've graphed our results with the NEED data for similar sized homes.

No promises that other users can achieve similar results.

policywonk

@wateroakley . That was genuinely worth reading.

KS2

@wateroakley thanks for the detailed post. I'm definitely going to roll out the smart trvs. I will also remove the 2 zones as 1 zone is literally the main bedroom and the towel radiator. Not even a standard trv on the bedroom rad presumably because it shouldn't be closed leaving the towel radiator on its own !! I plan to join the zones together that way I could change the main bedroom rad to a smart trv and then have the towel come on when any other area calls for heat