Are Smart Thermostats Worth It?

Smart thermostat companies claim savings of 20-30%. That's probably optimistic. But the real question is whether they save enough to justify the cost—and I think for most people, the answer is yes. Let me show my working.

The Realistic Savings

Independent studies (not manufacturer-funded) suggest smart thermostats save around 10-15% on heating bills. That's less than the marketing claims, but still significant.

Let's do the maths for a typical UK home:

• Average UK gas bill (heating): ~£800/year
• 10% savings: £80/year
• 15% savings: £120/year

Smart thermostat cost: £150-250 (including installation if needed)

Payback period: 1.5-3 years

After that, it's pure savings. Given that a smart thermostat lasts 5-10 years, the economics make sense.

Where the Savings Come From

Not heating an empty house. This is the big one. If you currently leave heating on a fixed schedule, a smart thermostat that knows you're not home (via phone location) stops wasting energy.

Learning your patterns. Systems like Nest learn when you typically need heat and optimise accordingly. No more waking up to a cold house because you forgot to adjust the timer.

Room-by-room control (if you add smart TRVs). Why heat the spare bedroom to 21°C when nobody's using it? Smart radiator valves let you heat rooms you're actually in.

Remote adjustment. Plans change. Working late? Turn the heating down from your phone. Coming home early? Warm the house up before you arrive.

When You'll Save Most

Smart thermostats save more if:

• Your schedule is unpredictable (you don't leave and return at fixed times)
• You currently leave heating on when out "just in case"
• You forget to adjust heating when going away
• You have a larger house with rooms that don't need constant heating

Smart thermostats save less if:

• You're home most of the time anyway
• You already manage your existing thermostat carefully
• You live in a small flat with minimal heating requirements

The Main Options

Hive

Cost: £150-180 (often available with installation deals)
Strengths: British Gas backed, simple app, widely compatible, good support
Weaknesses: Learning features aren't as sophisticated as Nest

Nest (Google)

Cost: £180-220
Strengths: Best learning algorithms, beautiful design, integrates with Google Home
Weaknesses: Doesn't work with all boilers, Google collects usage data

Tado

Cost: £150-200 (subscription for advanced features)
Strengths: Excellent geofencing, good smart TRV system for room control
Weaknesses: Some features require monthly subscription (£3-5/month)

Our Recommendation

For most UK homes: Hive. It's reliable, widely compatible with UK boilers, and British Gas installation deals often make it the most cost-effective option.

If you want the smartest automation and don't mind Google: Nest. The learning features are genuinely impressive once it's had a few weeks to understand your patterns.

If you want room-by-room control: Tado with smart TRVs. More complex setup, but the granular control can significantly increase savings in larger homes.

The Honest Answer

Are smart thermostats worth it? For most people, yes—they'll pay for themselves within 2-3 years and continue saving money after that. Plus the convenience of controlling heating from your phone is genuinely useful.

But if you're already disciplined about managing your heating and have a predictable schedule, the savings will be modest. You might be better putting that £200 toward insulation or draught-proofing, which often delivers better returns.