Compressor Not Running — Only Electric Backup Element Active
Why your heat pump uses only the electric element and how to fix it
My heat pump is using only the electric element — the compressor isn't running
This is a relatively common issue, especially when testing schedules or boost modes. If you see the electric auxiliary heater (elpatron / tillsats) running at full power while the compressor shows 0 RPM, here's what may be happening.
Why this happens
- Too high a demand setting — If you request a very high hot water temperature quickly, the system may jump straight to electric heating rather than running the compressor gradually.
- Max supplementary heat cap — Setting a maximum backup cap of 1 kW or less may conflict with some schedule configurations and prevent the compressor from activating correctly.
- Conflicting schedule blocks — Two overlapping time blocks with different settings can cause unexpected behaviour.
- Defrost or protection mode — The unit may be in a temporary protection state preventing the compressor from running.
What to try
- Check for any active alarms in the app — resolve these first.
- If you've set a schedule with a "boost hot water" block, try setting the maximum supplementary heat to 3 kW instead of 1 kW to allow the compressor to activate alongside it.
- Ensure your schedule blocks do not overlap in time.
- Restart the heat pump from the display or app and observe whether the compressor starts within 5–10 minutes.
Still not working?
If the compressor consistently fails to run, this may indicate a fault. Contact support with your serial number and a description of the settings you've used.
Email: support@qvantum.com