Heat pumps · Error codes · Intergas
n074Intergas · Xtend hybrid heat pump
n074 on an Intergas Xtend hybrid heat pump: Defrost mode stopped due to a water temperature that is too low
Short answer
On an Intergas heat pump, n074 means: Defrost mode stopped due to a water temperature that is too low. The heat pump keeps running. An engineer is needed to fix the cause.
Reviewed 24 September 2026 · 1 source
What it means
The manual says: Defrost mode stopped due to a water temperature that is too low.
Part involved: water circuit frost protection.
Likely causes:
- Check the flow; possibly low water volume.
Is it safe?
| Does the heat pump stop? | No |
|---|---|
| Severity | Warning |
| Engineer needed? | Yes |
The heat pump keeps running.
Resetting itself: unknown.
What you can check
- Note the code shown on the controller and the model number on the unit's rating label before contacting your installer.
- Check that the heat pump's isolator and consumer-unit breaker are on; do not open any casing.
What the engineer will check
- Check water flow and outlet water temperature sensor.
- Check antifreeze heaters and defrost operation.
- Check system water volume.
Who to ask for: Heat pump engineer.
Certification: Heat pump installer competence; F-gas and flammable-refrigerant (R32/R290) handling competence for any refrigerant-circuit work.
What you might notice
Sources
- Intergas Xtend Monoblock Heating Solutions Installation Instructions V1.2 (88302401w) ↗ · V1.2 · page p.74 · Reviewed 24 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 24 September 2026