Are smart thermostats worth it?
Nest, Hive, Tado and the rest. What they actually save, what they do not, and whether to add one when you replace your boiler.
14 July 2026 · 5 min read
A smart thermostat costs £150 to £250 fitted, and it is the single most common upsell on a boiler quote. Sometimes it is worth it. Often the claims are overstated.
What they genuinely do
They stop you heating an empty house. If your routine is irregular, that is a real saving, and the more irregular your life the bigger it gets.
They let you heat rooms separately, if you add smart radiator valves. Heating the bedroom and not the spare room is a genuine efficiency gain.
They give you visibility. People who can see their heating usage tend to use less of it, which is a slightly annoying but well-documented effect.
What they do not do
They do not make your boiler more efficient. The boiler burns gas at the same rate. A smart thermostat changes WHEN it burns, not how well.
The manufacturer claims of '£300 a year saved' assume you were previously heating an empty house badly. If you already have a decent programmable thermostat and a sensible routine, the saving is far smaller - realistically £50 to £100.
The one feature that actually matters
Load compensation or weather compensation, if your boiler supports it. This lets the boiler modulate its flow temperature down in milder weather, which keeps it condensing and genuinely lifts efficiency.
Most people fit a smart thermostat and never enable it. If your installer offers OpenTherm or a compensating control, that is the bit worth paying for - not the app.
Should you add it to a boiler quote?
It is cheaper fitted at the same time than later, because the engineer is already there and the wiring is already exposed. If you were going to want one, get it now.
If you are stretching to afford the boiler, skip it. It is not the thing that saves you money - the boiler is.