Every Part of Your Heat Pump System, Explained in Simple Terms
At Banshee Boilers, we want to help you understand your heat pump system. If you've recently purchased a new home, you might have received minimal information about your system or were simply advised "Don’t touch it." You're not alone in this. These systems are often misunderstood, and with widespread misinformation and unsolicited advice from neighborhood message groups, it can feel quite overwhelming. In this guide, we’ll explain every component of your heat pump in straightforward terms.
Moving Heat from Air to Water
Your Heat Pump is a super-efficient heat mover that circulates a chemical called refrigerant. This chemical changes from a liquid to a gas, while absorbing heat from outside. The Heat Pump then moves this heat-filled gas to a “heat exchanger”, where it transfers its heat to the water in your system. This causes the refrigerant to cool down, change into a liquid, and go back outside to collect more heat, repeating the cycle and keeping your home nice and warm. It's a continuous loop of heating magic.
The two most common types of air to water heat pump are known as Monobloc and Split
Monobloc:
The refrigerant and refrigeration equipment are housed entirely within the outdoor unit. Water from your heating system is pumped to this unit, where it is heated and then sent back into your home to your hot water cylinder and radiators, or underfloor heating.
In short: Water pipes link the indoor and outdoor unit
A monobloc system does not require its installer to have Refrigerant handling or F-Gas certification.
Split:
The refrigerant equipment is split between the indoor and outdoor unit and the refrigerant in the system is circulating between the two units. The water that circulates in your heating system is pumped through the indoor unit only. There it is heated and sent to your cylinder and radiators or underfloor.
In short: Refrigerant pipes link the indoor and outdoor unit
A Split system does require its installer to have Refrigerant handling or F-Gas certification.
Both systems come with their own set of advantages and disadvantages, however the most frequent issues in both systems arise due to installer error.
Parts of a heat pump outdoor unit
- Refrigerant: A chemical that absorbs and releases heat as it circulates through the heat pump system. It changes state from liquid to gas and back, facilitating heat transfer.
- Evaporator Coil: Absorbs heat from the outside air into the refrigerant, causing it to boil.
- Expansion Valve: Controls the flow of refrigerant into the evaporator coil, reducing its pressure and temperature.
- Compressor: Increases the pressure and temperature of the refrigerant, moving it through the system
- Heat Exchanger (Mono Bloc Only) (Condenser): Transfers heat from the refrigerant to the water that flows to the cylinder coil and heat emitters (radiators, underfloor).
- Filter/Strainer(Mono Bloc Only): Collects debris from the water to protect the system components.
- Fan: Draws air across the evaporator coil to facilitate refrigerant heat absorption.
- Temperature and Pressure Sensors: Monitor the system's operating conditions to ensure optimal performance and safety.
- Printed Circuit Board (PCB): The control centre of the heat pump, managing the operation of various components.
- Clearance Measurements: Ensure adequate space around the unit for proper airflow and maintenance.
- Electrical Isolator Switch: Allows the unit to be safely disconnected from the electrical supply for maintenance or emergency purposes.
Parts of a heat pump indoor unit
Heat Exchanger (Split Only) : Transfers heat from the refrigerant to the water that flows to our cylinder coil and heat emitters (radiators, underfloor).
Water Circulation Pump: Moves heated water through the system to our cylinder coil and heat emitters (radiators, underfloor).
Electrical Backup Heater: Provides additional heating if the heat pump cannot meet the demand.
Electrical Immersion Heater: Heats water directly in the hot water storage tank.
Diverter Valve: Directs the flow of heated water to either the heating system or the hot water storage cylinder.
Water Flow Sensor: Monitors the flow rate of water to ensure efficient operation.
Filter/Strainer/Magnaclean: Collects debris from the water to protect the system components.
Heating Expansion Vessel: Cushions the expansion of water as it heats up, preventing pressure build-up.
Pressure Relief Valve (3 bar): Releases excess pressure to prevent damage to the system.
Hot Water Storage: Stores heated water for domestic use.
Temperature and Pressure Sensors: Monitor the conditions within the indoor unit to maintain safe and efficient operation.
Printed Circuit Board (PCB): Controls the functions of the indoor unit, similar to the outdoor unit.
Heating system parts
Heat Pump Controller: Manages the overall operation of the heat pump system.
Thermostats: Measure and regulate the temperature demand within the home.
Motorised Valves/Actuators: Control the flow of water to different parts of the heating system.
Radiators/Underfloor: Emit heat into the rooms.
Thermostatic Radiator Valve: Allows some control of the temperature supply in each room.
Underfloor Heating Manifold: Distributes heated water to underfloor heating circuits.
Glycol Antifreeze (Monobloc only): Prevents the heating system from freezing and helps with heat transfer and corrosion inhibiting
Corrosion Inhibitor: Prevents oxidizing and rust in systems that contain steel components and do not have antifreeze added.
Plumbing Equipment
Booster Pump: Increases water pressure in the home.
Cold Water Storage: Stores cold water for use in the home.
Group Inlet Valve: Controls and balances the flow of pressurized water into the system.
Pressure Relief Valve: A safety device protecting the system by releasing excess pressure.
Potable Expansion Vessel: Cushions the expansion of potable water to prevent pressure build-up.
