ALRM022 on a Trianco Activair Indoor R32 5/7kW: High water temperature during domestic hot water production
Short answer
On a Trianco heat pump, ALRM022 means: High water temperature during domestic hot water production. 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: High water temperature during domestic hot water production.
Part involved: water flow / water temperature.
When it shows: max(PT5, PT6, PT4) > PF28; restores < PF28 - PM1.
Likely causes:
- Set point setting too high.
- Incorrect type of domestic hot water storage tank.
- DHW temperature probe PT4 not positioned correctly.
Is it safe?
| Does the heat pump stop? | Not stated |
|---|---|
| Severity | Fault — clears by itself when the condition goes |
| Engineer needed? | Yes |
The manual does not say whether the heat pump stops.
Resetting itself: Generally automatic when the activation condition clears (conditions must persist e.g. 30 s).
Manual reset: If the alarm trips repeatedly (e.g. 3 times in 1 hour) it must be reset manually by the Technical Assistance Centre (press and hold the reset key until padlock and alarm symbol clear).
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 heating system pressure gauge reading (if one is fitted) and tell your engineer if it is below the level set at commissioning; do not attempt to refill unless you have been shown how.
What the engineer will check
- Check for: Set point setting too high.
- Check for: Incorrect type of domestic hot water storage tank.
- Check for: DHW temperature probe PT4 not positioned correctly.
Who to ask for: heating / hydraulics.
Certification: Competent heating engineer (manufacturer training recommended).
What you might notice
Sources
- Trianco Activair Indoor Air Source Heat Pump 5 & 7kW - Control Panel Operation Manual ↗ · 2024-11 · page 41-42 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026