Correct way to install heat pump circulation water pump(with photo)

The circulation water pump is very important to the heat pump performance.
We must calculate carefully the water resistance to choose a big enough water pump to ensure the heat pump to work in the best way.
Normally the air to water heat pump is designed to increase the inlet water temp 5 ºC. If the inlet water temp is 30 ºC?the perfect outlet water temp is 35ºC. If the water pump is too small, the water flow volume will be small, the outlet water may become 38~39ºC. It will affect the heat pump performance and may reduce the heat pump COP (efficiency).
To keep the heat pump to work in perfect condition, better keep the heat pump as following water flow volume with following formula.
Perfect Water flow volume = heat pump capacity(W) / 1.16 / 5

Sometimes the customer may be confused by some malfunction of circulation water pump and it is not working continuously. Sometimes it looks the heat pump is not working. Then you need to check if the circulation water pump is not at the correct location. Very important! better to keep the water pump at the lowest level of the water circulation.
For example, the following circulation water pump location is at the top of the water tank. It must be avoided.

Please be reminded to clear the water filter every half year to avoid the blocking of water way.

The following water filter is necessary to be installed to protect the heat exchanger.

One of the recommended correction heat pump circulation connection is as following