Heat pumps · Error codes · Aira
THERMOSTAT-LOW-BATTERYAira · Heat Pump (Aira Outdoor Unit)
THERMOSTAT-LOW-BATTERY on an Aira Heat Pump: Batteries must be replaced soon
Short answer
On an Aira heat pump, THERMOSTAT-LOW-BATTERY means: Batteries must be replaced soon. The heat pump keeps running.
Reviewed 23 September 2026 · 1 source
What it means
The manual says: Batteries must be replaced soon.
Part involved: Aira Room Thermostat batteries (3x AAA).
Likely causes:
- Batteries depleted.
Is it safe?
| Does the heat pump stop? | No |
|---|---|
| Severity | Information only |
| Engineer needed? | No |
The heat pump keeps running.
Resetting itself: yes.
Manual reset: no.
What you can check
- Replace the 3x AAA batteries (rechargeable or single-use, do not mix types); do not leave empty batteries in the device.
What the engineer will check
- None.
Who to ask for: Aira-employed Clean Energy Technician (R290 heat pump).
Certification: Aira-trained/licensed technician; R290 flammable refrigerant competence for refrigerant work.
What you might notice
Sources
- Get to know your Aira Heat Pump system (homeowner guide, UK) ↗ · UK homeowner guide · page ManualsLib pp.10-11 (printed pp.19-20) · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026