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Daikin Airconditioning UK Ltd  The Heights, Brooklands, Weybridge, Surrey KT13 0NY

T 01932 879000    Email:
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Cleansing, flushing and protecting a heat pump installation

When installing a heat pump, one important aspect to consider before installation is the cleansing, flushing and protection of the heating system. This is vital to ensure the efficient operation of the heat pump in both new and existing systems.

General Recommendations
  1. Cleansing procedures should be carried out either with the old heating appliance in place or with the heat pump isolated from the system during the cleansing procedure.
  2. Before starting any cleansing, check the condition of the system. The cleansing process may remove settled contaminants that were previously covering holes in system components and this may lead to leaks. If in doubt, repair or replace the faulty components.
  3. If a full bore flushing valve is not available, temporarily replace a radiator valve with one and connect via a hose to foul drain.

Two Common Flushing Procedures
  1. Power flushing uses a machine to pump and / or heat water through a heating system without using the heat pump system circulator.
  2. Mains pressure flushing uses the old system appliance to circulate system water. Mains cold water is flushed through individual system components alternately to remove contaminants. In both cases, the system should be flushed until the water runs clear and all particles are removed. If using a chemical cleanser, please follow the manufacturer’s instructions carefully. The system water should be tested after flushing to ensure all cleanser has been properly removed from the system.

Filling the system
Please ensure the automatic air purge valve is open and fill with water to approximately 2 bar pressure. Remove as much air from the system as possible. Check that the backup heater vessel is filled with water by opening the pressure relief valve; water must flow out of the valve. If glycol is being added to the system, ensure this is fully mixed with water before filling.

All Daikin heat pumps are delivered with a standard 1mm mesh filter. This will not remove small particles like carbon which may damage the heat pump. It is strongly recommended to install an additional magnetic or cyclone filter on the heating water circuit.