Heat pumps · Error codes · Firebird
77Firebird · Enviroair (Hitachi Yutaki M based) 7.5-16kW monobloc
77 on a Firebird Enviroair 7.5-16kW monobloc: Receiver communication failure
Short answer
On a Firebird heat pump, 77 means: Receiver communication failure. The manual does not say whether the heat pump stops. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 1 source
What it means
The manual says: Receiver communication failure.
Part involved: controller/PCB communication.
Likely causes:
- No OpenTherm / H-LINK communication for a continuous period of 10 minutes.
Is it safe?
| Does the heat pump stop? | Not stated |
|---|---|
| Engineer needed? | Yes |
The manual does not say whether the heat pump stops.
What you can check
- Note the exact code shown on the controller (a photo helps) and report it to your installer or the manufacturer's service line.
- Check the heat pump's supply breaker/isolator at the consumer unit is on (do not open any casing).
- Check the controller display is lit and showing the code.
- If the controller shows red/alarm, the Firebird Enviroair Hitachi end-user guide allows a reset by pressing the ON button for 3 seconds and again; if it goes red again, contact your engineer.
What the engineer will check
- Check: No OpenTherm / H-LINK communication for a continuous period of 10 minutes.
Who to ask for: heat pump controls / electrical.
Certification: Electrical competence (Part P / qualified electrician) for work inside control panels.
What you might notice
Sources
- Firebird Enviroair Air Source Heat Pumps - Installation & Operation Manual (Enviroair 7.5/11/14/16kW, R410A monobloc) ↗ · Dec 2017 · page 53 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026