Problem

Frost is forming on the evaporator of your heat pump

Origin

The frost is the consequence of the cold generated by the heat pump on the wet evaporator. This is therefore quite normal. If the amount of frost is very high, it may be due to a blocked evaporator (dirty), a lack of gas, or an electronic fault.

Resolution

1 - Cleaning the evaporator

The evaporator needs to be clean to provide maximum performance. It can be cleaned with a no pressure water jet or with our cleanPAC product.

2 - Automatic defrosting

Our heat pumps are all equipped with a defrosting system (passive or active depending on the model). An ambient temperature sensor will trigger this system.

Passive defrosting stops the compressor from operating, while the fan continues to run.

Active defrosting will reverse the compressor cycle. The compressor will then generate heat to defrost the evaporator more quickly.

Once defrosted, the heat pump will automatically start heating again.

3 - Gas fault

If the quantity of frost is very large, or is created very quickly, we ask you to check the correct quantity of gas in the heat pump with the help of the pressure gauge located on the outside of the pump. 

In order to ensure that the gas quantity is correct, please check the value indicated on the pressure gauge located on the front of your heat pump (when it is switched off). 
The needle should indicate, to within a few units, the equivalent of the outside temperature. 
For example (blue arrow), 20°C of outside air corresponds to approximately 200PSI, or 1.37MPa or 13.7bar.

  

* If the gauge needle indicates more than 10°C difference from the actual outside temperature, there is likely a gas leak in the heat pump. Please create a service folder.
* If the gas quantity is correct, please check the defrost parameters.

4 - Defrost parameters

It is possible to act directly on the de-frost settings of the heat pump. To do this, please bring your manual and go to the paragraph "setting default parameter", as well as on the page of the "table of parameters". You can then act on:

- defrost activation temperature;
- defrost de-activation temperature;
- duration of defrost (or defrost interval)
- Self-activation time before defrosting begins (depending on model)

4 - Permanent Frost

If the heat pump does not meet the defrost parameters (Chapter 3 above), and the amount of ice is significant (see photo) the problem may be from the defrost sensor which is misplaced or defective, or the electronic card itself.

- Please disconnect the heat pump electrically.

- Remove the top cover from the heat pump to access the electrical box and open the cover.

  

- Ensure that all connection plugs, especially temperature sensors, are properly connected (by pressing).

  

If the problem persists, then the electronic card is to be replaced.

In case your product is out of warranty (more than 2 years or more than 3 years for the Premium range only), you can order the spare parts on our support site.

If your product is still under warranty (less than 2 years or less than 3 years for the Premium range only), return to the previous page and click on "Support request for this item".