Summary of Contents for Mitsubishi Electric EHST20C-VM2C.UK
Page 1
CYLINDER UNIT December 2014 No. OCH570 SERVICE MANUAL R410A [Model name] [Service Ref.] Note: EHST20C-VM2C.UK EHST20C-VM2C • This manual describes only service data of cylin- EHST20C-VM6C.UK EHST20C-VM6C der unit. EHST20C-YM9C.UK EHST20C-YM9C • RoHS compliant products have mark on the EHST20C-TM9C.UK...
Do not position furniture or electrical appliances below the outdoor unit or cylinder unit. The discharge pipework from the emergency devices of the cylinder unit should be installed according to local law. Only use accessories and replacement parts authorised by Mitsubishi Electric ask a qualified technician to fit the parts. Electrical All electrical work should be performed by a qualified technician according to local regulations and the instructions given in this manual.
Page 4
WARNING (SPLIT MODELS ONLY) Do not discharge refrigerant into the atmosphere if refrigerant leaks during installation, ventilate the room. Use appropriate tools for high pressure refrigerant. When pumping down refrigerant , stop the compressor before disconnecting the refrigerant pipes. During installation securely fasten the refrigerant pipes before starting the compressor. Check that refrigerant gas does not leak after the completion of installation.
Page 5
[1] Cautions for service (1) Perform service after recovering the refrigerant left in unit completely. (2) Do not release refrigerant in the air. (3) After completing service, charge the cycle with specified amount of refrigerant. (4) When performing service, install a filter drier simultaneously. Be sure to use a filter drier for new refrigerant.
(UK split / packaged model system) (Split model system) (Packaged model system) PART NAMES AND FUNCTIONS (UK split/packaged model system) (Split model system) (Packaged model system) For installation of EHST20*-*M*EC model, make sure to install a primary - ...
OUTLINES AND DIMENSIONS 5-1. Technical Drawings Pressure relief valve Pressure relief valve (Primary circuit) (Sanitary circuit) Air vent G1/2 G1/2 Main controller Terminal block Front panel 67.8 127.8 342.3 402.3 470.7 462.3 510.7 522.3 ...
Page 9
5-2. Service access diagrams Service access Parameter Dimension (mm) c (distance behind unit not visible in the right figure) Sufficient space MUST be left for the provision of discharge pipework as detailed in National and Local Building Regulations. The cylinder unit must be located indoors and in a frost-free environment, for example in a utility room, to minimise heat loss from stored water.
WIRING DIAGRAM 6-1. EHST20C-VM2C, EHST20C-VM2EC, EHST20D-VM2C, EHPT20X-VM2C Indoor unit powered Indoor unit powered by independent source via outdoor unit To outdoor To outdoor Power supply Power supply Immersion heater (1Ph3kW)(Option) unit unit ~/N 230V 50Hz to Booster heater Power supply Connect them using either way as shown below.
Page 11
6-2. EHST20C-VM6C, EHST20C-VM6EC, EHPT20X-VM6C Indoor unit powered Indoor unit powered by independent source via outdoor unit To outdoor To outdoor Power supply Power supply Immersion heater (1Ph3kW)(Option) unit unit ~/N 230V 50Hz to Booster heater Power supply Connect them using either way as shown below.
Page 12
6-3. EHST20C-YM9C, EHST20C-YM9EC, EHPT20X-YM9C Indoor unit powered Indoor unit powered via outdoor unit by independent source To outdoor Power supply To outdoor Immersion heater (1Ph3kW)(Option) unit unit ~/N 230V 50Hz Power supply Power supply to Booster heater Connect them using either way as shown below.
Page 13
6-4. EHST20C-TM9C, EHPT20X-TM9C Indoor unit powered Indoor unit powered by independent source via outdoor unit To outdoor To outdoor Power supply Power supply Immersion heater (1Ph3kW)(Option) unit unit ~/N 230V 50Hz to Booster heater Power supply Connect them using either way as shown below.
Page 14
6-5. EHST20C-MEC, EHST20D-MEC, EHST20D-MHC Indoor unit powered Indoor unit powered by independent source via outdoor unit To outdoor To outdoor Power supply Immersion heater (1Ph3kW)(Option) unit ~/N 230V 50Hz unit Power supply Connect them using either way as shown below. to Immersion heater ~/N 230V 50Hz Tool...
Page 15
6-6. EHPT20X-MHCW, EHST20C-MHCW, EHST20D-MHCW Indoor unit powered Indoor unit powered via outdoor unit by independent source To outdoor To outdoor Power supply Immersion heater (1Ph3kW) unit unit ~/N 230V 50Hz Power supply Connect them using either way as shown below. to Immersion heater ~/N 230V 50Hz Tool...
Page 16
6-7. DIP switch setting Located on the FTC printed circuit board are 4 sets of small white switches known as DIP switches. The DIP switch number is printed on the circuit board next to the relevant switches. The word ON is printed on the circuit board and on the DIP switch block itself.
FIELD WIRING Breaker abbreviation Meaning ECB1 Earth leakage circuit breaker for booster heater ECB2 Earth leakage circuit breaker for immersion heater Terminal block 1 Option 1: Cylinder unit powered via outdoor unit <1 phase> Affix label A that is included with the manuals near each Cylinder unit wiring diagram for cylinder unit and outdoor units.
Page 18
<3 phase> Affix label A that is included with the manuals near each wiring diagram for cylinder unit and outdoor units. Cylinder unit Outdoor unit To control board Wiring Power Earth circuit supply leakage breaker circuit 400 V breaker Isolating 50 Hz switch ECB1...
Page 19
Option 2: Cylinder unit powered by independent source. If the cylinder unit and outdoor unit have separate power supplies, the following requirements MUST be carried out: Initial settings White (Power supplied by CN01 outdoor unit) • Change the interconnected wiring in the control and electrical box of the Cylinder unit cylinder unit (see Figure 7-3). control board • Turn the outdoor unit DIP switch SW8-3 to ON.
Page 20
<3 phase> Affix label B that is included with the manuals near each wiring diagram for cylinder unit and outdoor units. Cylinder unit Wiring Power To control circuit supply Earth board breaker leakage 230 V circuit Isolating 50 Hz breaker switch Outdoor unit Wiring...
for the part names. *1 Refer to the following section [Local system]. (Split model system) Refrigerant pipe Water pipe Cold water Note Drain • To enable draining of the cylinder unit an isolating valve should be posi- tioned on both the inlet and outlet pipework.
Page 22
Maximum primary working pressure 2.5 bar 2.5 bar 2.5 bar * EN60335/Type 3000W single phase 230V 50Hz, length 460 mm. Use only Mitsubishi Electric service parts as a direct replacement.
(Packaged model system) Water pipe Cold water...
Page 23
Local system 1-zone temperature control Zone1 Zone1 2-zone temperature control 1-zone temperature control with boiler Zone1 Zone1 Zone2 2-zone temperature control with boiler 1-zone temperature control (2-zone valve ON/OFF control) Zone1 Zone1 Zone2 Zone2 1. Zone1 heat emitters (e.g. radiator, fan coil unit) (local supply) 10.
Page 24
Filling the cylinder unit (Primary circuit) 1. Check all connections including factory fitted ones are tight. 2. Insulate pipework between cylinder unit and outdoor unit. 3. Thoroughly clean and flush, system of all debris. (Refer to 4.2 in the installation manual.) 4.
CONTROLS 9-1. Main Controller L e t - Name Function Screen Screen in which all information is displayed Menu Access to system settings for initial set up and modifications. Back Return to previous menu. Confirm Used to select or save. (Enter key) Power/Holiday If system is switched off pressing once will turn system on.
9-2. Setting the Main Controller After the power has been connected to the outdoor and cylinder units (See chapter 7) the initial system settings can be entered via the main controller. 1. Check all breakers and other safety devices are correctly installed and turn on power to the system. 2.
Page 27 Initial Unrestricted access Installer only Main screen * Short press for 1 Zone system. Information Long press Option Forced DHW ON ( )/OFF ON ( )/Prohibited ( )/Timer ( ) Heating ON ( )/Prohibited ( )/Timer ( ) Consumed electrical energy Short Press Delivered energy...
Page 28 Initial Unrestricted access Installer only Main screen Main Menu menu Long press Manual operation Long Press Function settings Service Thermistor adjustment Password ON/OFF protected Economy settings for pump Delay ON/OFF Electric heater (Heating) Delay ON/OFF (Booster heater/Immersion heater) Auxiliary settings...
9-4. Service Menu The service menu provides functions for use by installer or service engineer. It is NOT intended the home owner alters settings within this menu. It is for this reason password protection is required to prevent unauthorised access to the service settings. The factory default password is "0000".
Page 30
Thermistor adjustment This function allows adjustments to be made to the thermistor readings from -10 – 10 °C in 0.5 °C intervals. 1. From the Service menu highlight Thermistor Adjustment 2. Press CONFIRM. 3. Use F1 and F2 to select thermistor. 4.
Mixing valve control 1. From the Auxiliary settings menu highlight Mixing valve control. 2. Press CONFIRM. 3. The Mixing valve control screen is displayed. 4. Use F1 and F2 buttons to set Running time between 10 to 240 seconds. The Running time equals to a period from full open of the valve (at a hot water mixing ratio of 100%) to full close (at a cold water mixing ratio of 100%).
Page 32 Heating operation This function allows operational setting of flow temperature range from the Ecodan and also the time interval at which the FTC collects and processes data for the auto adaptation mode. Menu subtitle Function Range Unit Default Flow temp.
1. General description End user can monitor accumulated*1 ‘Consumed electrical energy’ and ‘Delivered heat energy’ in each operation mode*2 on the main controller. *1 Monthly and Year to date *2 - DHW operation - Space heating Refer to the menu tree in “9-3. Main Settings Menu” for how to check the energy, and “6-7. DIP switch setting” for the details on DIP-SW setting. Either one of the following two method is used for monitoring.
Page 34 Demand control(IN4) The selection of “OFF”, whilst a signal is being sent to IN4, forcefully stops all the heat source operations and the selection of “Boiler” stops operations of heat pump and electric heater and performs boiler operation. Outdoor thermostat (IN5) External input settings menu screen The selection of “Heater”, whilst a signal is being sent to IN5, performs...
This function shows the current installer/user entered settings. Abbreviation Explanation Abbreviation Explanation HWtemp DHW max temperature Z2 mode Operation mode HWdrop DHW temperature drop - HER (Heating room temperature) HWtime DHW max operation time - HE (Heating flow temperature) NO HW DHW mode restriction - HCC (Heating compensation curve)
Resetting the password If you forget the password you entered, or have to service a unit somebody else installed, you can reset the password to the factory default of 0000. 1. From the main settings menu scroll down the functions until Service Menu is highlighted.
Request Request content Range Unit code Error history 1 (latest) Displays error history. ("– –" is displays if no history is present.) Code Error history 2 (second to last) Displays error history. ("– –" is displays if no history is present.) —...
Page 38
Indoor unit switch setting display (Request code: 162 to 166) 0: OFF 1: ON 0: OFF 1: ON SW1, SW2, SW3, SW4, SW5 SW1, SW2, SW3, SW4, SW5 Display Display 00 00 00 40 00 01 00 41 00 02 00 42 00 03 00 43...
Page 39
Indoor unit switch setting display (Request code: 162 to 166) 0: OFF 1: ON 0: OFF 1: ON SW1, SW2, SW3, SW4, SW5 SW1, SW2, SW3, SW4, SW5 Display Display 00 80 00 C0 00 81 00 C1 00 82 00 C2 00 83 00 C3...
Page 40
Output signal display (Request code: 175/553) Please refer to Table 2 on relevant wiring diagram whilst using the following. 0: OFF 1: ON 0: OFF 1: ON Display Display xx 40 xx 00 xx 01 xx 41 xx 02 xx 42 xx 43 xx 03 xx 04...
Page 41
Output signal display (Request code: 175/553) Please refer to Table 2 on relevant wiring diagram whilst using the following. 0: OFF 1: ON 0: OFF 1: ON Display Display xx C0 xx 80 xx C1 xx 81 xx C2 xx 82 xx C3 xx 83 xx C4...
Page 42
0: OFF 1: ON Output signal display (Request code: 175/553) Display Please refer to Table 2 on relevant wiring diagram whilst using the following. 40 xx 41 xx 0: OFF 1: ON 42 xx 43 xx Display 44 xx 00 xx 45 xx 01 xx 46 xx...
Page 43
Input signal display (Request code: 176/554) Please refer to Table 1 on relevant wiring diagram whilst using the following. 0: OFF (open) 1: ON (short) 0: OFF (open) 1: ON (short) Display Display 00 00 00 40 00 01 00 41 00 02 00 42 00 03...
Indoor unit only operation Indoor unit only operation In indoor unit only operation, an operation without connecting outdoor unit is possible. Indoor unit When in Indoor unit only operation the main control has control functions. Necessary Heat pump Not necessary ...
TROUBLESHOOTING 10-1. Troubleshooting Present and past Error codes are logged and displayed on the main controller or control board of the outdoor unit. Please refer to the table below and subsequent explanations to diagnose and remedy typical problems that may occur in the field. Unit Condition Error Code Action...
Page 46
10-4. Self diagnosis and action Check if DIP SW is set correctly. (Refer to Section 6-7.) Error code Title and display conditions Possible Cause Diagnosis and action Circulation water temperature overheat Insufficient system head Refer to table in section 10-6. to determine protection if system pump meets requirements.
Page 47
Error code Title and display conditions Possible Cause Diagnosis and action P1/P2/L5/LD Indoor unit temperature thermistor failure Connector/terminal wire has become Visually check the terminals and connec- * The thermistors subject to failure can be checked detached or loose wiring. tions and reattaches appropriate.
Page 48
Error code Title and display conditions Possible Cause Diagnosis and action Heating operation error THW1 has become detached from its Visually inspect location and reattach as * “3” is displayed in “Request code: 567” in “Run- holder. necessary. ning information”. ...
Page 49
Error code Title and display conditions Possible Cause Diagnosis and action Low primary circuit (Zone2 side) flow rate Insufficient system head If more head required either add an pump of the same size or replace existing pump. detected by flow switch Reduced flow in primary water circuit Check circulation pump (See 10-6. for how * “3”...
Page 50
Error code Title and display conditions Possible Cause Diagnosis and action E0/E4 Main controller communication failure 1. Contact failure with transmission cable 1. Check connection cable for damage or (Reception error) loose connections at the FTC and main Error code E0 is displayed if main controller does controller terminals.
Page 51
Error code Title and display conditions Possible Cause Diagnosis and action Indoor unit/wireless receiver communication 1. Connection fault with wireless receiver- 1. Check the connections to the wireless re- failure FTC connection ceiver and FTC have not become loose and Error code J0 is displayed when the FTC can not that the connecting cable is not damaged.
Page 52
10-5. Troubleshooting by inferior phenomena Fault symptom Possible cause Explanation - Solution Main controller display 1. There is no power supply to main 1. Check LED2 on FTC. (See 6. WIRING DIAGRAM.) is blank. controller. (i) When LED2 is lit. Check for damage or contact failure of the main controller wiring.
Page 53
Contact your Mitsubishi Electric dealer. 7. Immersion heater cut-out tripped. 7. Check immersion heater thermostat and press reset button, located on im- mersion heater boss, if safe.
Page 54
Contact your Mitsubishi Electric dealer. 5. Immersion heater cut-out has been triggered. 5. Check immersion heater thermostat and press reset button located on im- mersion heater boss, if safe.
Page 55
Fault symptom Possible cause Explanation - Solution In 2-zone tempera- When Zone1 and Zone2 are both in heating Normal action no action necessary. ture control, only mode, the hot water temperature in Zone2 Zone2 does not does not exceed that in Zone1. reach the set tem- Faulty wiring of motorized mixing valve Refer to installation manual, "5.3 Wiring for 2-zone temperature control".
Page 56
Fault symptom Possible cause Explanation - Solution Water discharges from If continual – field supplied pressure Check function of pressure reducing valve and replace if necessary. expansion relief valve reducing valve not working. - part of Inlet Control If continual – expansion relief valve may be Turn the handle on the expansion relief valve to check for foreign objects Group damaged.
Page 57
10-6. Checking component parts' function Part Name Check Points Water circulation pump (primary circuit) EHST20C series 80.0 Speed 5 (Default setting) 70.0 Speed 4 BROWN PWM input signal 60.0 Speed 3 Signal cable BLUE Speed 2 Signal ref.
Page 58
Part Name Check Points Flow sensor Flow signal Yellow White Flow signal V Green 5V DC Brown CN1A 0.35V Flow [l/min] Booster heater Measure the resistance between the terminals with a tester. Thermostat (90 °C) and thermal cut out (121 °C) Terminal Normal Abnormal...
Page 59
Part Name Check Points 3-way valve (1) Check the movement of the red indicator. The red indicator normally points to A in DHW mode and to B in Heating mode as shown to the left. (2) If each indicator position is correct but the 3-way valve does not work prop- Motor erly, the motor may not fit onto the valve securely, so remove the motor by pressing the release button, and reinstall it.
Page 60
10-7. Test point diagram FTC (Controller board) CNP1/OUT1 (TBO.1 1-2) Water circulation pump1 OUT2 (TBO.1 3-4) (230V AC) Water circulation pump2 (Local supply) (230V AC) OUT3 (TBO.1 5-6) Water circulation pump3 CN01 (Local supply) (230V AC) Power supply (230V AC) CNP4/OUT14 Water circulation pump4 (230V AC)
DISASSEMBLY PROCEDURE ● Prepare the proper tools. ● Prepare the proper protectors. ● Provide adequate ventilation. ● After stopping the operation of the cylinder and outdoor unit, turn off the power-supply breaker and remove the power plug. ●...
Page 62
PHOTOS DISASSEMBLY PROCEDURE 3. How to remove the electrical parts Earth leakage circuit Photo 3-1 Control box breakers (ECB1, ECB2) (Step (1) is applied to all the following parts.) (1) Remove the front panel (Refer to Procedure 1). (Photo 3-1) (2) Disconnect all the lead wires from the earth leakage cir- Controller board...
Page 63
PHOTOS DISASSEMBLY PROCEDURE 4. How to remove the control box Photo 4-1 (1) Remove the front panel (Refer to Procedure 1). Cable (2) Disconnect only the lead wires in the control box that Bracket (R) clamps connect to the components in the cylinder unit. Photo 4-2 shows the control box before the related lead Screw wires are disconnected.
Page 64
DISASSEMBLY PROCEDURE PHOTOS 5. How to remove water pump (primary circuit)/pump valve/ Photo 5-1 strainer valve (1) Remove the front panel (Refer to Procedure 1). Quick connection (2) Disconnect the CNP1 connector, the earth cable and the O-ring CNPWM connector in the control box.
Page 65
From the previous page. DISASSEMBLY PROCEDURE PHOTOS Photo 5-5 Cover Strainer mesh (inside) (6) Remove the 2 screws on the strainer valve stay. (Photo 5-1) (7) Remove the strainer valve by detaching the quick con- nection. • When reinstalling the quick connection, use a new O-ring.
Page 66
DISASSEMBLY PROCEDURE PHOTOS Photo 7-1 7. How to remove the flow sensor (1) Remove the front panel (Refer to Procedure 1). (2) Disconnect the CN1A connector on the controller board. (Photo 4-2) (3) Release the flow sensor lead wire from the cable clamp, Nut (G1") the fastener and the cable strap in the control box, and O-ring...
Page 67
DISASSEMBLY PROCEDURE PHOTOS 8. How to remove the booster heater Photo 8-1 Controller Control box Earth leakage circuit board (1) Remove the front panel (Refer to Procedure 1). breaker (ECB1) (2) Disconnect the CNBHT connector on the controller board, and the booster heater lead wires wired to the BHC1 (Lead wire No.1, No.2 and No.3) and BHC2 (Lead wire No.4, No.5 and No.6) contactors respectively and release the lead wires from the fastener, the cable...
Page 68
From the previous page. DISASSEMBLY PROCEDURE PHOTOS Photo 8-3 (3) Remove the DIV frame by removing the 2 screws on it, and Booster heater O-ring remove the cushion by cutting the band. Then remove the rubber by cutting the band. (Photo 8-2) (4) Close (OFF) the pump valve.
Page 69
DISASSEMBLY PROCEDURE PHOTOS 9. How to remove the thermostat/immersion heater Photo 9-1 (1) Remove the front panel (Refer to Procedure 1). (2) Peel off the water-proof tapes on the plastic head of the thermostat in order to reveal the thermostat terminals, and disconnect the lead wires from the terminals.
Page 70
DISASSEMBLY PROCEDURE PHOTOS 10. How to remove the plate heat exchanger (P-HEX) Photo 10-1 (Refrigerant - Water) (1) Pump down the refrigerant circuit and close the stop Band DIV frame valve at the outdoor unit side. (Refer to 12. SUPPLEMENTARY INFORMATION.) (2) Remove the front panel (Refer to Procedure 1).
Page 71
From the previous page. DISASSEMBLY PROCEDURE PHOTOS 10. How to remove the plate heat exchanger (P-HEX) Photo 10-4 (Refrigerant - Water) (7) Remove the thermistor (TH2) from the thermistor pocket Expansion vessel (Refer to Procedure 20). (8) Remove the manometer with the manometer cover (Refer to Procedure 11).
Page 72
From the previous page. DISASSEMBLY PROCEDURE PHOTOS 10. How to remove the plate heat exchanger (P-HEX) Photo 10-8 Pump stay (15) Remove the pump stay by removing the 3 screws on it. (Photo 10-8) (16) Remove the 3 screws on the front frame (L), and 1 screw on the bottom.
Page 73
DISASSEMBLY PROCEDURE PHOTOS 11. How to remove the pressure relief valve / manometer / air vent (automatic) Photo 11-1 Manometer Manometer (1) Remove the front panel (Refer to Procedure 1). cover (2) Swing the control box to the front (Refer to Procedure 4). ...
Page 74
From the previous page. DISASSEMBLY PROCEDURE PHOTOS 11. How to remove the pressure relief valve / manometer / air Photo 11-5 Air vent vent (automatic) (automatic) Pressure relief valve (3 bar) (3) Remove the field piping from the pressure relief valve (3 bar).
Page 75
DISASSEMBLY PROCEDURE PHOTOS Photo 12-1 12. How to remove the expansion vessel (1) Remove the front panel (Refer to Procedure 1). Expansion vessel Flare joint Flare nut (2) Swing the control box to the front (Refer to Procedure 4). (3) Remove 2 tapes. (Photo 12-1) •...
Page 76
DISASSEMBLY PROCEDURE PHOTOS Drain cock for P-HEX 15. How to remove the drain cock (primary circuit) Photo 15-1 (Pipe side) (1) Remove the front panel (Refer to Procedure 1). (2) Remove the drain cock from the pump valve by turning the drain cock.
Page 77
DISASSEMBLY PROCEDURE PHOTOS 17. How to remove the plate heat exchanger (P-HEX) (1) Remove the front panel (Refer to Procedure 1). (2) Drain water in the P-HEX (Water-Water) using the drain Photo 17-1 cock (Primary circuit) and the drain cock (Sanitary circuit).
Page 78
PHOTOS DISASSEMBLY PROCEDURE Photo 19-1 19. How to remove the scale trap (sanitary circuit) (1) Remove the front panel (Refer to Procedure 1). (2) Disconnect the CNP4 connector and the earth cable in Nut (G3/4"), the control box. (Photo 4-1) Gasket (G3/4") (3) Release the water pump lead wire from the 2 cable clamps and the cable strap in the control box, the 2...
Page 79
DISASSEMBLY PROCEDURE PHOTOS 20. How to remove the liquid refrigerant temp. thermistor Thermistor Thermistor Photo 20-1 (TH2) / flow water temp. & return water temp. thermistor Band (THW1,THW2) / tank water temp. thermistor (THW5) (1) Remove the front panel (Refer to Procedure 1). (2) Disconnect the following thermistor connectors on the controller board and release the lead wires from cable clamps and bands.
Page 80
DISASSEMBLY PROCEDURE PHOTOS 21. How to remove the side panels Photo 21-1 (1) Remove the front panel (Refer to Procedure 1). Side panel (Right) (2) Remove the 4 screws on the top panel, and remove the 2 screws that hold the top panel onto the back panel. (Photos 21-2 and 22-1) (3) Remove the side panel (right) by removing the 7 screws fixing the side panel (right).
Page 81
DISASSEMBLY PROCEDURE PHOTOS Photo 22-1 22. How to remove the back panel (1) Remove the front panel (Refer to Procedure 1). (2) Remove the side panels (Refer to Procedure 21). Screws (Top panel) Top panel (3) Remove the 4 screws on the back panel, and remove the 2 screws that hold the back panel onto the frame.
Page 82
DISASSEMBLY PROCEDURE PHOTOS & ILLUSTRATION Photo 23-1 23. How to detach and attach the quick connection Refer to the following steps when detaching and attaching the quick connection. (1) Remove the clip. (Photos 23-1 and 23-2) (2) Separate the connected parts to remove the O-ring. (Photo 23-3) Clip •...
Page 83
Notes on replacing the parts Replacement of the parts listed below requires the following procedure. After the parts are removed, eliminate loctite on threads by applying loctite remover, apply new loctite, and then install and tighten the parts to the specified tighten- ing torques below.
SUPPLEMENTARY INFORMATION Refrigerant collecting (pumpdown) for split model systems only Refer to “Refrigerant collection” in the outdoor unit installation manual or service manual. Back-up operation of boiler Heating operation is backed up by boiler. For more details, refer to the installation manual of PAC-TH011HT-E.
SERVICE AND MAINTENANCE Engineers Forms Should settings be changed from default, please enter and record new setting in ‘Field Setting’ column. This will ease resetting in the future should the system use change or the circuit board need to be replaced. Commissioning/Field settings record sheet Main controller screen Parameters...
Page 86
(From the previous page.) Engineers Forms Commissioning/Field settings record sheet (continued from the previous page) Default Field Main controller screen Parameters Notes setting setting Service Pump speed Pump speed(1 - 5) menu Heat source setting Standard/Heater/Boiler/Hybrid *7 Standard Operation Heating operation Flow temp.range Min.temp.(25 - 45°C) 30°C...
Page 87
Annual Maintenance Log Book Contractor name Engineer name Site name Site number Cylinder unit maintenance record sheet Warranty number Model number Serial number Mechanical Frequency Notes Turn OFF water supply, drain DHW tank, remove mesh from strainer clean and replace in strainer. *1 Keep water supply OFF, open hot water taps and check the primary-side expansion vessel charge pressure.
Page 88
HEAD OFFICE : TOKYO BLDG., 2-7-3, MARUNOUCHI, CHIYODA-KU, TOKYO 100-8310, JAPAN Copyright 2014 MITSUBISHI ELECTRIC CORPORATION Distributed in Dec. 2014 No. OCH570 New publication, effective Dec. 2014 Made in Japan Specifications are subject to change without notice.
