Winter has arrived and you notice that your outdoor heat pump is defrosting even though it is not very cold. You wonder if this is normal and if something is wrong. The answer is yes, it is indeed normal for your outdoor heat pump to defrost even when the outside temperature is not very cold. The outdoor heat pump is designed to automatically defrost when it detects condensation or ice on the outdoor unit.
Ice may form on the unit when the outdoor air humidity is high. This can happen even when the outside temperature is relatively mild. Another reason why your outdoor heat pump might defrost even when it's not very cold is that the indoor and outdoor cooling system may not be properly balanced. If the indoor temperature is too high compared to the outdoor temperature, the outdoor unit can compensate by generating a defrost.
Finally, another factor that can lead to defrosting is the use of automatic heat pump speed control. The speed of the heat pump can be automatically adjusted to adjust the amount of heat produced by the outdoor unit according to outdoor conditions. This can result in defrosting when outside conditions are milder.
So what can you do if your outdoor heat pump is defrosting even though it's not very cold?
The first step is to check the balance of the indoor and outdoor cooling system. You can do this by verifying that the indoor temperature is set correctly in relation to the outdoor temperature. If the indoor temperature is too high compared to the outdoor temperature, you may need to adjust the indoor temperature. You should also check if the automatic speed adjustment of the heat pump is activated.
If so, you may need to turn it off to prevent defrosting when the outside temperature is milder.