Let’s talk TRVs (Thermostatic Radiator Valves); for those without these on your radiators you could be missing out on significant energy bill savings (some argue up to 40% although we’d guess closer to 20%), and for those with them you might learn something from this (we certainly did in writing this) and for those swapping to smart TRVs you may see an additional 5% annual heating bill saving.
What do the numbers mean?
Manual TRVs all have numbers on them and twist, these numbers relate to the air temperature in the room, meaning (roughly) the following:
0 – off
* – come on under 7°C
1 – come on under 10-15°C
2 – come on under 15-17°C (recommended setting for most)
3 – come on under 18-20°C (recommended setting for most)
4 – come on under 21-22°C (recommended for elderly/young)
5 – max (valve is always open)
They’re quite awesome bits of kit and cost between £10-£30 each making them very affordable, they basically have a pin inside the unit that pushes down or up when the air temperature changes, which in turn allows more or less hot water from your hot water system to enter the radiator which either heats or cools the room.
How much am I going to save on my bills?
This again will vary dramatically on your current setup, usage etc but heating rooms that you’re not using is obviously costing you money so having the ability to control the temps of these radiators will lower your bills (if you remember to actually lower them), but it’s hard to give an accurate figure, lots of manufacturers claim 20-40% savings on heating bills compared with not having them at all but these figures are a bit of a guess in our opinion so you should take them with a pinch of salt but not totally ignore the potential.
Do I need a plumber to install?
Most likely but it depends on your DIY Skills and your existing setup, they’re available on most DIY sites:
and any confident DIYer or Plumber can install them (please get advice/learn how properly as you could cause a big issue if doing it wrong), however, if you don’t have one we would actually recommend you look at Smart TRVs (see below) for increased functionality and potential cost savings.
A plumber likely will charge you per radiator and at a guess of 10 fully installed it would set you back roughly a half day of labour.
What about Smart TRVs / eTRVs?
Smart TRVs use technology to offer the same benefits as manual TRVs but they do it automatically via schedules, location data from your phone/s, app controls or Smart Speakers, this makes them infinitely more useful compared to manual ones and more likely actually to be used.
Will a Smart TRV save me more money?
Probably but it’s hard to give an accurate figure as it will again depend on so many variables; compared with a manual TRV (as listed above or what most homes should have) you likely will save ~2-5% per year having a properly setup automated/smart system vs manually going around and doing it yourself (but again that massive depends on how often you currently go around and adjust them each day and your setup), that means an average UK household (who consumes 12,000kWh of gas per year) would be looking at a £27 to ~£70 annual saving.
The question you need to ask yourself is every night before bed are you going to go around and manually turn off all your radiators in the living room, hall, kitchen etc and increase the temps in your upstairs rooms and then the opposite in the morning? If the answer is no, because that sounds like a right faff then a smart TRV setup is likely a good buy for you.
What Smart TRVs are available?
► ► ► Which Smart TRV is best? Sadly there isn’t one that is the best and stands out for us, they all offer similar features but it depends on your existing boiler setup + existing thermostat setup on which is best for your requirements. You will have to do your own research and weigh up manual Vs smart options. Several of the above require upgrading your boiler thermostat as well so if you already have a smart Thermostat (E.g. Nest) your experience may vary.