We all know that, for air source heat pumps, the thermal insulation and adequate antifreeze measures in winter are very important. A little carelessness will bring direct economic losses to users, and even more serious consequences. What reason lead heat pumps to freeze up and crack in winter?
1. The unit is powered off for a long time
When the temperature is lower than -5°C, if the power outage lasts for more than 4 hours, it is likely to cause the heat exchanger to freeze and crack. In particular, when the fluorine circuit system and the water circuit system are frozen at the same time, and the compressor restarted after the power turned on, the compressor will directly suck the water from the external water circuit into the fluorine system, causing the entire unit to be scrapped. Therefore, when it is judged that the power outage may be prolonged for a long time, all the water in the unit, the water pump and the outdoor pipeline should be drained to prevent the unit from freezing.
2. The heat pump unit main electrical board is not designed with anti-freeze protection function
When the air temperature is lower than 0°C, as long as the unit is powered on, no matter whether the unit is working or reports a fault code, the unit will automatically supply power to the circulating pump for 10 to 15 seconds every 30 minutes, so that the hot water in the water tank will be circulated to heat the valves, pipes, water pumps and heat exchangers to prevent freezing and cracking. However, each manufacturer’s machine design is different, and some heat pumps motherboards do not have anti-freeze protection function. Once a fault occurs, it may cause the heat
exchanger to freeze up and crack.
3. In summer, the water flow switch is not installed or the water flow switch is short-circuited, and the temperature measurement of the temperature probe is not accurate.
When the air source heat pump is used for cooling in summer, the unit stops working when the water temperature is between 0°C and 10°C, and starts to work when it is higher than 15°C. If the water temperature probe does not measure the water temperature accurately, for example, the water temperature has reached 0 °C, and the probe shows that the temperature is still at 25 °C (over 15 °C), then the machine will judge that the water temperature has not reached the temperature that needs to be shut down, and will continue to cool. At this time, if the water flow switch is not installed or short-circuited, the unit may freeze and crack.