Heat pumps · Error codes · Ideal Heating
H7Ideal Heating · HP290
H7 on an Ideal Heating HP290: Mains High Voltage or Low Voltage Error
Short answer
On an Ideal Heating heat pump, H7 means: Mains High Voltage or Low Voltage Error. 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: Mains High Voltage or Low Voltage Error.
Part involved: mains supply.
Likely causes:
- Mains supply voltage outside 170-270 V AC.
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 code or fault message shown on the controller/Halo and when it appeared; check the heat pump's isolator and consumer-unit breaker are on. Check whether lights or other appliances are also affected (possible supply problem) and whether any breaker/RCD has tripped - do not reset repeatedly.
What the engineer will check
- Measure supply voltage at XT1; if outside limits refer to electricity provider; otherwise replace inverter PCB.
Who to ask for: Heat pump engineer competent with R290 (A3, highly flammable); refrigerant-circuit work requires Cat I/II F-gas plus City & Guilds 6187-21 or equivalent (I&M p.93 warning).
Certification: Electrical work by competent person.
Sources
- HP290 Monobloc Heat Pump System - Installation & Maintenance (UIN 240080 A09) ↗ · UIN 240080 A09 · page 103 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026