Service And Maintenance - Mitsubishi Electric Ecodan EHSC-VM6D-CN Installation Manual

6

Service and Maintenance

The indoor hydrobox must be serviced once a year by a qualified individual. Ser-
vicing and maintenance of the outdoor unit should only be done by a Mitsubishi
Electric trained technician with relevant qualifications and experience. Any electri-
cal work should be done by a tradesperson with the appropriate electrical quali-
Error Codes
Code Error
L3 Circulation water temperature overheat protection
L5 Indoor unit temperature thermistor (THW1, THW2) failure
L6 Circulation water freeze protection
L8 Heating operation error
L9 Low primary circuit flow rate detected by flow sensor
LF Flow sensor failure
LL Setting errors of DIP switches on FTC control board
LP Out of water flow rate range for outdoor heat pump unit
P1 Thermistor (Room temp.) (TH1) failure
P2 Thermistor (Ref. liquid temp.) (TH2) failure
P6 Anti-freeze protection of plate heat exchanger
E0 - E5 Communication failure between main remote controller and FTC
E6 - EF Communication failure between FTC and outdoor unit
E9 Outdoor unit receives no signal from indoor unit.
U*, F* Outdoor unit failure
A* M-NET communication error
Note: To cancel error codes please switch system off (Press button F4(RESET) on main remote controller).
Annual Maintenance
It is essential that the hydrobox is serviced at least once a year by a qualified individual. Any required parts MUST be purchased from Mitsubishi Electric (safety matter).
NEVER bypass safety devices or operate the unit without them being fully operational.
Note
▪ Within the first couple of months of installation, remove and clean the hydrobox's strainer plus any additional filter items that are fitted external to the
hydrobox. This is especially important when installing on an old/existing pipe work system.
▪ The PRV valve (No. 10 on Figure 3.3) should be checked annually by turning the knob manually so that the medium is discharged, thus cleaning the seal
seat.
In addition to annual servicing it is necessary to replace or inspect some parts after a certain period of system operation. Please see tables below for detailed instructions.
Replacement and inspection of parts should always be done by a competent person with relevant training and qualifications.
Parts which require regular replacement
Parts Replace every
Pressure relief valve (PRV)
Air vent (Auto/Manual) 6 years
Manometer
Parts which require regular inspection
Parts
Possible failures
Pressure relief valve
(3bar)
Water leakage
Water circulation pump
Parts which must NOT be reused when servicing
* O-ring
* Gasket
Note:
• Always replace the gasket for pump with a new one at each regular maintenance (every
20,000 hours of use or every 3 years).
• Make sure to carry out annual check (turn the cap) on 3bar PRV. This is not required for
5bar PRV.
fications. Any maintenance or 'DIY' fixes done by a non-accredited person could
invalidate the Warranty and/or result in damage to the hydrobox and injury to the
person.
Action
Flow rate may be reduced. Check for;
• Water leakage
• Strainer blockage
• Water circulation pump function (Error code may display during filling
of primary circuit, complete filling and reset error code.)
Check resistance across the thermistor.
See Action for L3.
Check and re-attach any thermistors that may have become dislodged.
See Action for L3. If the flow sensor itself does not work, replace it.
Caution: The pump valves may be hot, please take care.
Check flow sensor cable for damage or loose connections.
Check DIP switches on FTC control board.
Check the installation Table 4.3.1
Check remote controller settings (Service menu / heat pump flow rate
range)
See Action for L3.
Check resistance across the thermistor.
Check resistance across the thermistor.
See Action for L3.
Check for correct amount of refrigerant.
Check connection cable for damage or loose connections.
Check that the outdoor unit has not been turned off.
Check connection cable for damage or loose connections.
Refer to outdoor unit service manual.
Check both units are switched on. Check connection cable for damage or
loose connections. Refer to outdoor unit service manual.
Refer to outdoor unit service manual.
Refer to outdoor unit service manual.
Check every
1 year
(turning the knob manually)
20,000 hrs (3 years)
Possible failures
PRV would be fixed and
expansion vessel would burst
Water circulation pump failure
22
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