Servicing & Maintenance Procedure - Grant Aerona 290 Installation & Operating Instructions Manual

• Leak detection fluids are suitable for use with most
refrigerants but the use of detergents containing chlorine
shall be avoided as the chlorine may react with the
refrigerant and corrode the copper pipework.
• If a leak is suspected, all naked flames shall be removed
or extinguished.
• If a leakage of refrigerant is found which requires
brazing, all of the refrigerant shall be recovered from the
system, or isolated (by means of shut off valves) in a
part of the system remote from the leak.
• Oxygen Free Nitrogen (OFN) shall then be purged
through the system both before and during the brazing
process.
13. Removal and evacuation

When breaking into the refrigerant circuit to make repairs or
for any other purpose conventional procedures shall be used,
However, it is important that best practice is followed since
flammability is a vital consideration.

All equipment used must be rated for use with A3
refrigerants.

The following procedure shall be adhered to:
• Remove refrigerant
• Purge the circuit with inert gas
• Evacuate
• Purge again with inert gas
• Open the circuit by cutting or brazing.


The refrigerant charge shall be recovered into the correct
recovery cylinders. The system shall be flushed with OFN to
render the unit safe. This process may need to be repeated
several times.


Compressed air or oxygen shall not be used for this task.

Flushing shall be achieved by breaking the vacuum in the
system with OFN and continuing to fill until the working
pressure is achieved, then venting to atmosphere, and finally
pulling down to a vacuum. This process shall be repeated
until no refrigerant is within the system.

When the final OFN charge is used, the system shall be
vented down to atmospheric pressure to enable work to take
place. This operation is absolutely vital if brazing operations
on the pipework are to take place.

Ensure that the outlet for the vacuum pump is not close to
any ignition sources and there is ventilation available.
14. Charging procedures

In addition to conventional charging procedures, the following
requirements shall be followed:
• Ensure that contamination of different refrigerants
does not occur when using charging equipment. Hoses
or lines shall be as short as possible to minimize the
amount of refrigerant contained in them.
• Cylinders shall be kept upright.
• Ensure that the refrigeration system is earthed prior to
charging the system with refrigerant.
• Label the system when charging is complete (if not
already).
• Extreme care shall be taken not to overfill the
refrigeration system.


Prior to recharging the system it shall be pressure tested
with OFN. The system shall be leak tested on completion
of charging but prior to commissioning. A follow up leak test
shall be carried out prior to leaving the site.
Section 10: Servicing
10.2 SERVICING & MAINTENANCE PROCEDURE
Grant Aerona 290 heat pumps require only the minimum of
routine maintenance. This should be carried out on an annual
basis by a qualified technician and consist of the following:
10.2.1 HEAT PUMP
Check the following
• There are no refrigerant leaks. Refer to Section 10.6.
• Visual condition of the heat pump
• Any obstructions to airflow into the ASHP – remove if found
• The fan outlet grille is not obstructed - remove obstructions if
found
• Condensate drain opening(s) are clear
• Pipe insulation condition
• Pressure relief valve hose discharge is clear
• Electrical power supply connections, hydraulic PCB and
connections.
Inspect and clean the evaporator
• The air inlet grille and evaporator must be checked and any
leaves or other debris removed from between the inlet grille
and evaporator fins.
! CAUTION !
Take care not to damage or distort the Aluminium fins of
the evaporator when removing any debris.
• Carefully remove any dirt or debris from the evaporator fins
using either a soft brush or by gently vacuuming. Take care
not to damage the fins during this manual cleaning process.
• Wash the evaporator with a neutral detergent cleaner, e.g.
EnviroCoil, using a low-pressure spray.
• Do NOT use a pressure washer to clean the evaporator fins
as this may damage them.
• Do NOT use any aggressive cleaning agents as these will
attack and damage the aluminium fins.
Inspect and clean the air outlet grille
• The air outlet grille must be checked and any leaves or
any other debris removed that could otherwise obstruct the
operation of the fan(s) or the free flow of air from the heat
pump.
• Ensure that both the air inlet to the evaporator and the
discharge from the fan outlet are unobstructed. Any foliage,
plants, etc. near the heat pump must not be allowed to grow
over the heat pump.
• Under no circumstances should anything be stacked on or
against the heat pump.
• Refer to Section 3.6.9 for the required clearances around the
heat pump.
Inspect the condensate disposal
• Check that the condensate drain holes in the bottom of the
heat pump are not blocked.
• Check that any condensate hoses are not blocked.
• Check that condensate is safely disposed of and not forming
a pool beneath and around the heat pump.
Inspect electrical supply connections
• Remove right hand end side panel and the cover panel from
the Hydraulic PCB enclosure.
• Visually inspect the electrical power supply connections
checking for obvious defects such as loose connections or
defective/damaged wiring. Also check Hydraulic PCB and
connections.
• Replace cover panel on hydraulic PCB housing and right-
hand end side panel when finished.
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