GCH15010
43
No.
Fault symptom
Possible cause
Explanation - Solution
5
LED2 on FTC is
blinking.
(See 6. WIRING
DIAGRAM)
When LED1 is also blinking on FTC .
Check for faulty wiring between FTC and outdoor unit.
Faulty wiring between FTC and outdoor unit
When LED1 on FTC is lit.
1. Faulty wiring in main remote controller
Multiple indoor units have been wired to a
single outdoor unit.
1. Check for faulty wiring in main remote controller.
The number of indoor units that can be wired to a single outdoor unit is one.
Additional indoor units must be wired individually to a single outdoor unit.
2. Short-circuited wiring in main remote control-
ler
2.,3. Remove main remote controller wires and check LED2 on FTC. (See 6. WIR-
ING DIAGRAM.)
If LED2 is blinking check for short circuits in the main remote controller wiring.
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- if LED2 is blinking, the main remote controller is faulty;
- if LED2 is lit, faulty wiring of the main remote controller has been corrected.
3. Main remote controller failure
6
LED4 on FTC is off.
(See 6. WIRING
DIAGRAM)
1. SD memory card is NOT inserted into the
memory card slot with correct orientation.
1. Correctly insert SD memory card in place until a click is heard.
2. Not an SD standards compliant memory card.
2. Use an SD standards compliant memory card. (Refer to installation manual,
"5.6 Using SD memory card".)
LED4 on FTC is
blinking.
(See 6. WIRING
DIAGRAM)
1. Full of data.
1. Move or delete data, or replace SD memory card with a new one.
2. Write-protected.
2. Release the write-protect switch.
3. NOT formatted.
3. Refer to installation manual, "5.6 Using SD memory card".
4.
4. FTC is Not compatible with NTFS file system. Use an SD memory card
formattedin FAT file system.
7
No water at hot tap.
1. Cold main off
1. Check and open stop cock.
2. Strainer (local supply) blocked.
2. Isolate water supply and clean strainer.
8
Cold water at tap.
1. Hot water run out.
1. Ensure DHW mode is operating and wait for thermal store tank to re-heat.
2. Prohibit, schedule timer or holiday mode se-
lected.
2. Check settings and change as appropriate.
3. Heat pump not working.
3. Check heat pump – consult outdoor unit service manual.
4. Booster heater cut-out tripped.
4. Check booster heater thermostat and press reset button if safe.
Reset button is located on the side of booster heater, covered with black rub-
5. The earth leakage circuit breaker for booster
heater breaker (ECB1) tripped.
5. Check the cause and reset if safe.
6. The booster heater thermal cut-out has
tripped and cannot be reset using the manual
reset button.
6. Check resistance across the thermal cut-out, if open then the connection is
broken and the booster heater will have to be replaced.
Contact your Mitsubishi Electric dealer.
7.
7.
8.
8.
9.
3-way valve fault
Air inclusion in pump A
System or power OFF
10. Flow sensor fault
11. Supply flow rate is low
9.
Check plumbing/wiring to 3-way valve.
Open the air vent above pump A (refer to page 25).
Turn on the power / system.
10.
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flow sensor A.
11. Increase the supply amount.
(i) Manually override 3-way valve using the main remote controller. (Refer to
<Manual operation> in section 9-4.) If the valve does not still function, go
to (ii) below.
(ii) Replace 3-way valve coil. If the valve does not still function, go to (iii) be-
low.
(iii) Replace 3-way valve. (Refer to 11. DISASSEMBLY PROCEDURE.)
Formatted in NTFS file system.
ber cap. See 4. PART NAMES AND FUNCTIONS to find out its position.
9
Water heating takes
longer.
1. Heat pump not working.
1. Check heat pump – consult outdoor unit service manual.
2. Booster heater cut-out tripped.
2. Check booster heater thermostat and press reset button if safe.
Reset button is located on the side of booster heater, covered with black rub-
3. Booster heater breaker (ECB1) tripped.
3. Check the cause and reset if safe.
4. The booster heater thermal cut-out has
tripped and cannot be reset using the manual
reset button.
4. Check resistance across the thermal cut-out, if open then connection is bro-
ken and the booster heater will have to be replaced.
Contact your Mitsubishi Electric dealer.
5. Flow rate of the primary circuit may be reduced.
5. Check the following items
Check for trapped air in water pump 1 (primary circuit).
Check water pump (primary circuit) for malfunction. (Refer to section 10-6.)
Check the pipe for blockage.
6. 3-way valve failure
6. Check plumbing/wiring to 3-way valve.
(i) Manually override 3-way valve using the main remote controller. (Refer to
<Manual operation> in section 9-4.) If the valve does not still function, go to (ii)
below.
(ii) Replace 3-way valve motor. If the valve does not still function, go to (iii) be-
low.
(iii) Replace 3-way valve. (Refer to 11. DISASSEMBLY PROCEDURE.)
ber cap. See 4. PART NAMES AND FUNCTIONS to find out its position.
