2186-b2 on a Kronoterm KSM system controller / KT-2A / Cloud.Kronoterm alarm list: Heating loop thermostat failure 3
Short answer
On a Kronoterm heat pump, 2186-b2 means: Heating loop thermostat failure 3. The heat pump stops until the fault clears or is reset. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 1 source
What it means
The manual says: Heating loop thermostat failure 3.
Part involved: Heating loop thermostat failure 3.
Likely causes:
- Heating loop thermostat failure 3.
Is it safe?
| Does the heat pump stop? | Yes |
|---|---|
| Severity | Fault — needs a manual reset once the cause is fixed |
| Engineer needed? | Yes |
The heat pump stops until the fault clears or is reset.
Resetting itself: Manual note: auto-reset attempted; if still active 10 min after auto-reset contact installer.
Manual reset: User may clear via KT-2A / Cloud.Kronoterm "Confirm"; conditions re-checked.
What you can check
- Note the full code (4-digit number + bit, e.g. 2186-b2) from the KT-2A diagnostic menu or Cloud.Kronoterm alarm list.
- Reset/confirm the alarm once from the KT-2A or Cloud.Kronoterm ("Confirm") as the manual allows; if still active 10 min after the reset, contact the installer who commissioned the system.
- Check the room thermostat/KT controller has power (batteries/display on) and settings are correct.
What the engineer will check
- Diagnose via KSM service menu / Cloud.Kronoterm technician access.
- Check sensor/communication wiring, connectors, module or sensor replacement.
Who to ask for: heat pump engineer (Kronoterm-trained).
Certification: Electrical competence.
What you might notice
Sources
- KRONOTERM KT-2A Controller operating instructions (technician, user) - ADAPT, VERSI, ETERA, WPLV and ADAPT MAX systems, 17-19-45-6702-08 ↗ · 17-19-45-6702-08 · page 38 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026