We all know that the heat preservation and antifreeze measures of the air source heat pump unit for heating in winter are very important, and a little carelessness will bring direct economic losses to users, and even produce more serious consequences. “Learning from history”, which reasons will lead to heat pump inner system crack and freeze? Here are 3 ones:
1. The unit is out of power for a long time.
When the temperature is lower than -2°C, if the power is cut 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 restarts after the power is turned on, the compressor will directly suck the water in the external water circuit into the fluorine system, causing the entire unit to be scrapped. Therefore, when it is judged that the power may be cut for a long time, all the water in the unit, water pump, and outdoor pipeline should be drained to prevent the unit from freezing.
2. The main board design of the unit has no antifreeze protection function.
When the temperature is below zero, as long as the unit is energized, regardless of whether the unit is working or reporting a fault code, the unit will automatically power the circulating pump for 10 to 15 seconds every 30 minutes so that the hot water in the water tank will circulate between the units, and use the hot water in the water tank to heat the valves, pipes, pumps and the heat exchanger, to prevent freezing and cracking. However, the design of each manufacturer’s machine is different. Some machine motherboards do not have anti-freeze protection. Once a failure occurs, the heat exchanger may freeze and crack.
3. No water flow switch is installed or short-circuited during summer cooling, and the temperature probe is not accurate.
When the air source heat pump cools in summer, the unit stops working when the water temperature is below 10℃, and starts to work when the temperature is higher than 15℃. If the water temperature probe is inaccurate, for example, the water temperature has reached 10°C, and the probe shows that the temperature is still 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 the water flow switch is short-circuited, it is likely that the heat pump will crack and freeze.
How to take anti-freezing measures for units? welcome to view more in this article.