Thermostat failure — repair, replace, or upgrade to smart
A dead thermostat is one of the fastest 'no heating' calls to fix — often flat batteries or a wiring nick from a decorator. It's also the perfect moment to consider upgrading to a smart thermostat if the old one is 10+ years and analogue.
Make it safe — before anything else
Only Gas Safe registered engineers work on gas
Any wiring back into the boiler side is Gas Safe. Battery changes and app resets are safe DIY.
Isolate before rewiring
Old wired stats are 230 V. Turn the boiler off at the consumer unit before touching the wiring.
What Kevin (our AI) will check first
Message Kevin and he'll ask exactly these questions before we send an engineer, so we bring the right parts on the first van.
- Thermostat make and model (or 'no idea, it's the beige one').
- Display blank, or showing a temperature but not calling for heat?
- Boiler make, model and how the stat is wired (240 V, low voltage, wireless receiver)?
- Any recent decorating, electrical work, or replaced batteries?
- Interested in a smart upgrade or just a like-for-like replacement?
Common causes of a thermostat failure
Flat batteries
Number one cause. 2× AA in most room stats and receivers. Free to check and fix yourself.
Failed room stat
10–15 years old, mechanical stats seize; digital stats lose the display. £90 – £160 for a like-for-like swap fitted.
Wireless receiver paired to the boiler failed
Common on Salus, Danfoss and Drayton wireless kits. Receiver needs re-pairing or replacing; £120 – £200 fitted.
Wiring damaged during decoration
Painter or electrician nicks a cable. Diagnosed with a multi-meter and re-terminated in under an hour.
Smart-stat setup fault
Nest / Hive / Tado paired to the wrong receiver, or Wi-Fi drops. Free to talk through in chat before booking a visit.
Honest cost band — why we won't quote blind
Typical
£90 – £160 for a like-for-like digital or programmable thermostat swap
Complex
Smart thermostat installed (Nest / Hive / Tado / Honeywell) £240 – £360 including labour.
£50 diagnostic covers full wiring / pairing checks. No manufacturer kickbacks — we recommend the stat that suits your boiler and lifestyle, not the one that pays commission.
Fixed £50 diagnostic
Flat fee. No hourly meter running.
Fair quote or refund
Transparent pricing — refunded if we don't fix it.
Vetted UK engineers
DBS-checked, insured, real reviews.
AI-triaged in seconds
KJ chats first so the right engineer arrives.
Related emergencies
See all in the emergency plumbing hub — or the leaks & water damage hub.
Areas we cover for thermostat failure
Same-day across Greater Manchester and Rochdale.
Thermostat failure — FAQs
Dealing with a thermostat failure? Chat with Kevin now
Real triage in seconds. £50 diagnostic visit — refunded if we don't fix it.
Related hubs: emergency plumbing, leaks & water damage, all services.
Chat with Kevin about Thermostat failure