BoilerTroubleshooting2026-02-26
Boiler Not Responding to the Thermostat
Check thermostat batteries and settings before suspecting wiring or the boiler.
When the boiler ignores the thermostat, the thermostat itself is the first suspect.
Common causes
Dead thermostat batteries, wrong mode, a lost wireless link, or a wiring fault can stop the thermostat controlling the boiler.
What to do
Replace batteries, confirm HEAT mode and re-pair a wireless thermostat; persistent issues need a wiring/PCB check.
Key takeaways
- Replace thermostat batteries
- Confirm HEAT mode
- Re-pair wireless thermostats
- Wiring faults need a technician
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