Troubleshooting Warmth Pumps

In troubleshooting warmth pumps which aren’t working correctly, it is very important know the primary parts that make up the gear. {The electrical} and digital components that management the gear are the ability provide, wires and printed circuit boards.

The mechanical components are the evaporator, condenser, compressor, metering machine and the 4-way valve.

Within the USA, often when the 4-way valve is ON, the system is working within the cooling mode. When it’s OFF, it’s working in heating mode. In another international locations, when the 4-way valve is ON, the system is working within the heating mode and vice-versa.

On this article, we’ll assume that when the 4-way valve is ON, the system is working in cooling mode.

Troubleshooting Warmth Pumps Issues & Options

Listed here are some frequent issues and the options that you could be need to verify in case your warmth pump shouldn’t be working. Relying in your information and experiences in troubleshooting warmth pumps, it’s good to seek out out what’s fallacious along with your gear although you might have to name the technicians to resolve the issues.  Take word that the issues listed under are particular to a sure case and the options could differ out of your models.

Troubleshooting Warmth Pumps Downside #1: Throughout summer time, after I run the warmth pump in cooling mode, no cool air is discharged however as an alternative scorching air is discharged. The issue is that the 4-way valve shouldn’t be switching ON because the relay controlling the valve shouldn’t be working.

Transistor controlling 4WV

Answer: The 4-way valve is activated by a 24V DC relay SPST contact. The coil of the relay is related to a 24V DC energy provide and is activated by a microcomputer by way of a transistor when it’s in cooling mode.

When the relay is activated, the SPST(single pole single throw) contact will shut and brought about the 4-way valve to be activated inflicting the warmth pump to run in cooling mode.

OFF the mains provide to the management board and verify the coil resistance of the relay through the use of a multi-meter. It’s discovered to be open circuit as an alternative of resistance of 15-25 ohm. This confirms that the coil of the relay is defective therefore the contact shouldn’t be in a position to change the 4-way valve to ON.

That is the rationale why it stays working in warmth mode. After the relay had been modified, the cooling mode works tremendous.

Troubleshooting Warmth Pumps Downside #2: My warmth pump system is unable to start out and all of the LEDs on the indoor unit are OFF. A extreme lightning and thunderstorm occurred the night time earlier than. Some digital parts have been broken due the the surge in voltage on the printed circuit board.

Answer: The technician used the multi-meter to verify the voltage to the transformer. It was discovered that there was no energy provide to it. The ability provide was obtainable earlier than the fuse. The mains was then OFF and the technician checked the fuse for continuity. It was open circuit, confirming that the fuse had been blown.

A piece of the circuit that reveals the fuse, varistor and transformer.

The transformer was additionally checked and located to have a resistance of 15-20 ohm which indicated that it had not been broken. The surge safety machine often called varistor was checked and it was discovered to have low resistance (<10 ohm) confirming that it had been broken. 

The lightning should have struck the ability provide of the constructing inflicting a surge of voltage onto the printed circuit board. This brought about the varistor to breakdown and an enormous present flowed by way of it and the fuse. ‘

The ingredient within the fuse open circuited after that. Solely these two gadgets have been broken. The opposite parts had been protected by way of the actions of those two parts. Each parts have been modified and the unit is working once more.

Troubleshooting Warmth Pumps Problem #3: Throughout winter, I exploit the cut up warmth pump in warmth mode however after some hours of operation, the out of doors unit turns into a block of ice. There’s a management board within the indoor unit and a defrost controller within the out of doors unit. The issue is that the defrost thermostat contacts aren’t closing to function the unit in defrost mode.  

Answer: In regular operation, when the time and temperature situations to enter defrosting mode have been achieved, the defroster thermostat will shut the contact of the reversing valve and open the contact to the out of doors fan.

It will pressure the unit to enter defrosting mode the place warmth from the within of the constructing might be used to warmth up the frost/ice on the out of doors unit. Throughout this time, the out of doors fan might be OFF. It will trigger the frost to be eliminated. After that, the defroster will return into regular heating mode.

The out of doors unit freezes up as a result of the defroster contacts aren’t in a position to shut as a result of defective part therefore the unit unable to enter defrosting mode. The defroster must be modified for it to function correctly once more.