Circulator Pump and Heat Pump System

What is a heat pump

A heat pump is an HVAC product that uses the heat of outside air, water or earth to efficiently heat your home in the winter and cool it in the summer. Unlike a furnace, a heat pump doesn’t burn fuel to make heat. It simply uses electricity to move heat from one place to another.

The most common type of heat pump is the air-source heat pump, which transfers heat between your house and the outside air. Today’s heat pump can reduce your electricity use for heating by approximately 50% compared to electric resistance heating such as furnaces and baseboard heaters.

Which kind of circulator pumps are working with heat pump

No matter what kind of heat pump you are using, a circulator pump plays an important role. It works like a heart to circulate the water in the heat pump system and increase the system pressure.

There are two types of circulators applicable for heating pump system.

One is 3-speed selectable control circulator. It is the most common type with the advantages of low noise level and small dimension.

Pump-LE25-6

The other one is smart high-efficiency circulator. It is the upgraded generation of circulator pumps with advantages of low energy consumption, smart control and compact design.

Trouble shooting for malfunctions of circulator pumps in heat pump system

Plastmax has been servicing for the heat pump market for many years. We have collected nearly all the circulator malfunction occurred in heat pump systems in recent five years. The most common malfunctions can be classified into four types, namely odd noise, rotor stuck, water leakage and motor burnt.

Odd Noise

Reason I: Water impurity gets into the gap of rotatable parts and cause friction and noise.

Solution I: Fix filter net in the heat pump system to keep the water clean in pipeline.

Reason II: If calcium or lime deposits are built up on pump rotor, or pump running without water(dry-run), it would cause the pump shaft worn, then noise comes up.

Solution II: Use water quality softener to decrease the calcium or lime deposits; Add the function of dry-run protection in the heat pump system.

Reason III: The water pressure is too much low in the pump inlet port and the cavitation cause the noise.

Solution III: Remain a water pressure above the minimum requirement.

Reason IV: The pump resonates with the system and cause the noise.

Solution IV: Choose a proper circulator pump of which the performance matches the requirement of the heat pump system; Consider vibration reduction while processing the pipeline.

Rotor Stuck

Reason I: Calcium or lime deposits can be built up on pump rotor and cause the locking of rotor, shaft and bearing.

Solution I: Use water quality softener to decrease the calcium or lime deposits; Regularly clean the calcium or lime deposits on the surface of the rotatable parts.

Reason II: The water impurity or foreign matters cause the rotor stuck.

Solution II: Fix filter net in the heat pump system to keep the water clean in pipeline.

Water Leakage

Reason I: The shield cover of pump has been worn and damaged caused by pump dry-run or running with water impurity.

Solution I: Keep the water clean and add the function of dry-run protection in the heat pump system.

Reason II: Improper position of pump gasket

Solution II: When reassemble the pump housing, make sure the gasket has been put in proper position and test.

Motor Burnt

Reason I: When power on, the pump motor would be over heat if the pump rotor stuck. It is dangerous and could cause pump motor burnt.

Solution I: Fix filter net in the heat pump system to keep the water clean in pipeline; Use water quality softener to decrease the calcium or lime deposits; Regularly clean the calcium or lime deposits on the surface of the rotatable parts.

Reason II: Motor winding interturn short circuit fault

Solution II: Keep the power supply voltage stable without overload. Frequent overload could cause motor over heat and accelerated deterioration of insulation layer.

Reason III: outside water leak into the control box

Solution III: Well protect the control box from outside water

Reason IV: Condensing water leak into the motor winding.

Solution IV: Choose a better circulator pump with condensing water proof structure; Make sure the pump has been fixed in correct direction.