The schedule timer mode allows daily and weekly space heating and DHW pat- terns to be entered.
. From the main settings menu use F2 and F3 to highlight the schedule timer icon then press CONFIRM.
2. The schedule timer sub menu will be displayed. The icons show the following modes;
3. Use F2 and F3 buttons to move between mode icons press CONFIRM to be shown the PREVIEW screen for each mode.
The PREVIEW screen allows you to view the current settings. Days of the week are displayed across the top of the screen. Where day appears underlined the settings are the same for all those days underlined.
Hours of the day and night are represented as a bar across the main part of the screen. Where the bar is solid black, space heating/DHW (whichever is selected) is allowed.
<Setting the schedule timer>
. In the PREVIEW menu screen press F4 button.
2. First select the days of the week you wish to schedule.
3. Press F2/F3 buttons to move between days and F to check or uncheck the box.
4. When you have selected the days press CONFIRM.
5. The time bar edit screen will be displayed.
6. Use buttons F2/F3 to move to the point at which you do not want the selected mode to be active press CONFIRM to start.
7. Use F3 button to set the required time of inactivity then press CONFIRM.
8. You can add up to 4 periods of inactivity within a 24 hour interval.
9. Press F4 to save settings.
When scheduling heating, button F changes the scheduled variable between time and temperature. This enables a lower temperature to be set for a number of hours e.g. a lower temperature may be required at night when the occupants are sleeping.
• The schedule timer for space heating and dHW are set in the same way.
However for dHW only time can be used as scheduling variable.
• A small rubbish bin character is also displayed choosing this icon will de- lete the last unsaved action.
• It is necessary to use the SAVE function F4 button to save settings CoN- FIrM does NoT act as SAVE for this 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.
From the main setting menu use F2 and F3 to highlight the service icon then press CONFIRM.
You will be prompted to enter a password. THE FACTory dEFAULT PASS- Word IS “0000”.
(It takes approx. 30 secs to load the service menu.)
The service menu is navigated using the F and F2 buttons to scroll through the functions. The menu is split across two screens and is comprised of the following functions;
Manual operation Function setting Thermistor adjustment Auxiliary setting Heat source setting Operation setting Running information Thermistor reading Summary of setting Error history Password protection Manual reset
In this Installation Manual, instructions will be given only for the following func- tions;
Auxiliary setting Manual operation Heat source setting Password protection Manual reset
Information on the other functions can be found by consulting the technical or service manuals.
Screen of service menu
Screen 2 of service menu
System off prompt screen
Action requires confirmation Action is confirmed
Many functions can not be set whilst the indoor unit is running. The installer should turn oFF the unit before trying to set these functions. If the installer at- tempts to change the settings whilst the unit is running the main controller will display a reminder message prompting the installer to stop operation before con- tinuing. By selecting yes, the unit will cease operation and changes can be made to the service settings.
If text is displayed in white on a black background, CONFIRM button must be pressed to save this choice.
Auxiliary setting menu screen
Economy settings for pump screen Auxiliary Setting
This function is used to set the parameters for any auxiliary parts used in the sys- tem.
From the service menu use F and F2 buttons to highlight Auxiliary setting then press CONFIRM.
From the Auxiliary setting menu highlight Freeze Stat Function.
The freeze stat function screen will be displayed.
Use buttons F3 and F4 to adjust the minimum outdoor temperature which freeze stat function will begin to operate, (3 - 20 °C) or choose .
If asterisk ( ) is chosen freeze stat function is deactivated/disabled (i.e. freeze risk).
<Electric heater (Space heating)>
From the Auxiliary Setting menu highlight Electric heater (Space heating).
The Electric heater (Space heating) screen is displayed.
Press F1 button to switch the function ON/OFF.
Use F3 and F4 buttons to adjust the time period of heat pump-only operation before the booster heater will assist in space heating. (5 -180mins)
<Electric heater (dHW)>
From the Auxiliary Setting menu highlight Electric heater (DHW).
The Electric heater (DHW) screen is displayed.
Press F1 button to switch the function ON/OFF.
Use F3 and F4 buttons to adjust the time period of heat pump-only operation before the booster heater and the immersion heater (if present) will assist in DHW heating. (15 -30mins)
<Economy settings for pump>
From the Auxiliary setting menu highlight Economy Settings for pump.
The economy settings for pump screen will be displayed.
Use button F1 to switch the pump ON/OFF.
Use buttons F3 and F4 to adjust the time the pump will run. (3 - 60 mins) .
Freeze stat function screen
Electric heater (Heating) screen
Electric heater (DHW) screen
Manual operation menu screen
System off prompt screen
Heat source setting screen
Cancel last action screen
During the filling of the system the pump and 3-way valve can be manually over- ridden using manual operation mode.
When manual operation is selected a small timer icon appears in the screen. The function selected will only remain in manual operation for a maximum of 2 hours.
This is to prevent accidental permanent override of the FTC3.
From the service menu use F and F2 buttons to scroll through list until Manu- al Operation is highlighted.
Manual operation menu screen is displayed.
To activate manual operation press the function button under the desired part.
To return to service menu press MENU or BACK button.
Pressing F3 button will switch manual operation mode ON for the main 3-way valve. When filling of the tank is complete the installer should access this menu again and press F3 to deactivate manual operation of the part. Alternatively after 2 hours manual operation mode will no longer be active and FTC3 will resume control of the part.
Manual operation and heat source setting can not be selected if the system is running. A screen will be displayed asking the installer to stop the sys- tem before these modes can be activated.
The system automatically stops 2 hours after last operation.
The OUT13 output of the 2-way valve 2 constitutes an inversion of the OUT4 output of the 2-way valve 1.
<Heat source setting>
The default heat source setting is heat pump and all electric heaters present in the system to be operational. This is referred to as Standard operation on the menu.
From the service menu use F and F2 buttons to scroll through list until Heat Source Settingis highlighted.
Heat source setting menu screen is displayed.
Press F3 button until preferred heat source is displayed.
To return to service menu press MENU or BACK button.
If you wish to return to the service menu without saving the setting press re- turn button. You will be asked if you are sure you wish to cancel the changes.
Choose Yes or No as appropriate.
operation Setting Menu
To access the Operation setting menu use F and F2 buttons to scroll through the service menu until Operation setting is highlighted.
Operation setting menu is displayed.
<Cold weather function>
For extremely low outdoor temperature conditions when the heat pump’s ca- pacity is severely restricted the heating or DHW is provided by only the electric booster heater (and immersion if present). This function is intended for use during extreme cold periods only. Extensive use of direct electrical heaters ONLY will result in higher electric usage and may reduce working life of heaters and related parts.
From the Operation setting menu use F and F2 buttons to scroll through the list until Cold weather function is highlighted.
Cold weather function screen is displayed.
To switch Cold weather function ON/OFF press F1.
To alter the temperature at which heater switching function starts use F3 and F4.
Note: Range of ambient (outdoor) temperature is -15°C to -10°C (default -15°C) To return to Operation setting menu press BACK.
<room Temp Control (Heating)>
This function allows operational setting of flow temperature range from the Eco- dan and also the time interval at which the FTC3 collects and processes data for the auto adaptation mode.
From the Operation setting menu use F and F2 buttons to scroll through the list until Room temp. control (HEATING) is highlighted.
Room temp. control (HEATING) screen is displayed.
To alter the time period at which date will be collected use F and F2 buttons to highlight ‘Temp. control interval’.
Use F3 and F2 buttons to alter the time interval.
Note: Range 10 – 60 minutes at 10 minute intervals (default 10 minutes).
To alter the flow temperature limits, use F1 and F2 buttons to highlight ‘Flow temperature range’.
Flow temperature range screen is displayed.
To alter minimum flow temp. use F1 and F2 buttons.
Note: Range of minimum flow temp. is 25°C to 40°C (default 30°C).
To alter maximum flow temp. use F3 and F4 buttons.
Note: Range of maximum flow temp. is 35°C to 60°C (default 50°C) To return to Operation setting menu press BACK twice.
Operation setting menu screen
Simultaneous operation screen
Cold weather function screen
Room temp. control (HEATING) screen
For periods of very low outside temperature this mode can be used. Simultane- ous operation allows both DHW and space heating to be provided simultaneously by using the heat pump to provide space heating whilst only the immersion heater (if fitted) provides heating for DHW. This operation is only available if BOTH a DHW tank AND immersion heater are present on the system.
From the Operation setting menu use F and F2 buttons to scroll through the list until Simultaneous operation is highlighted.
Simultaneous operation screen is displayed.
To switch simultaneous operation ON/OFF press F1.
To alter the temperature at which simultaneous operation starts use F3 and F4.
Note: Range of ambient (outdoor) temperature is -15°C to 10°C (default -15°C).
To return to Operation setting menu press BACK.
Password protection is available to prevent unauthorised access to the service menu by untrained persons.
From the service menu use F and F2 buttons to scroll through list until Pass- word protection is highlighted.
When password input screen is displayed use buttons F and F2 to move left and right between the four digits, F3 to lower the selected digit by , and F4 to increase the selected digit by .
When you have input your password press CONFIRM.
The password verify screen is displayed.
To verify your new password press button F3.
Your password is now set and the completion screen is displayed.
To return to service menu press MENU or BACK button.
Password input screen
<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.
From the main settings menu scroll down the functions until Service Menu is highlighted.
You will be prompted to enter a password.
Hold down buttons F3 and F4 together for 3 secs
You will be asked if you wish to continue and reset the password to default set- ting.
To reset press button F3.
The password is now reset to 0000.
Password verify screen
Should you wish to restore the factory settings at any time you should use the manual reset function. Please note this will reset ALL functions to the factory de- fault settings.
From the service menu use F and F2 buttons to scroll through list until Manu- al Reset is highlighted.
The manual reset screen is displayed.
Choose either Manual Reset for FTC3 or Main Controller.
Press F3 button to confirm manual reset of chosen device.
Before commissioning the hydrobox system complete the following table to ensure the necessary checks are carried out.
No System commissioning checklist Notes
Installation location Air flow around the unit Outdoor unit Good/Poor
2 Maintenance access Hydrobox Good/Poor
Outdoor unit Good/Poor
3 Pipe work Total pipe length Outdoor to indoor m
4 Height difference Outdoor to indoor m
5 System chemically cleansed and
6 Insulation type and thickness
7 Electrical wiring Correct cables used
8 Electrical maintenance access Good/Poor
9 Connection of mains power source Outdoor unit electric cable
Type Size Indoor unit electric cable
0 Connection of control cable
Anti-freeze Refer to product guidelines. %
2 Check pre-charge in the expansion vessel(s) Yes/No
3 Pressurise circuit to bar Yes/No
4 Release air from system Yes/No
outdoor unit operation checklist
5 Outdoor unit details Model No. Serial No.
6 Power source (V) ø L - N
3ø L - L2 L2 - L3 L3 - L
7 Excessive vibration/noise Compressor Yes/No
8 Unit mounted on anti-vibration pads (Tico Pads) Yes/No
9 Provision made for condensate removal Yes/No
For system installations which include DHW cylinders, for known hard water areas, see advice in section 4.2 General.
The indoor hydrobox must be serviced once a year by a qualified individual.
Servicing and maintenance of the outdoor unit should only be done by a Mitsubi- shi Electric trained technician with relevant qualifications and experience. Any electrical work should be done by a tradesperson with the appropriate electrical
qualifications. 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.
basic Troubleshooting for Hydrobox
Fault symptom Possible cause Solution
Water discharges from pressure relief valve
If continual – pressure relief valve seat may be damaged. Remove cartridge – check seat and renew if necessary.
If intermittent – expansion vessel charge may have reduced/blad- der perished.
Check pressure in expansion vessel. Recharge to bar if neces- sary. If bladder perished replace vessel.
System was excessively pressurised at fill stage. Ensure the fill connection has been physically DISCONNECTED from the mains water supply. With hydrobox cold check pressure in hydrobox. If necessary, discharge/re-fill system to the recom- mended cold-fill pressure of 1 bar.
Unit has overheated – thermal controls have failed. Switch off power to the heat pump. Leave water supply on. Wait until discharge stops. Isolate water supply and replace if faulty.
Noisy pump Air in pump Use manual and automatic air vents to release excess air from
system. Top up water if necessary to achieve bar on primary cir- cuit.
Pump runs for a short time for no reason.
Pump jam prevention mechanism to inhibit the build up of scale. Normal operation no action necessary.
Heating system does not get up to set temperature.
Prohibit, schedule timer or holiday mode selected. Check settings and change as appropriate.
Incorrectly sized radiators Contact installer
The room in which the temperature sensor is located is at a differ- ent temperature to the rest of the house.
Reposition the temperature sensor to a more suitable room.
Battery problem *wireless control only Check the battery power and replace if flat.
Mechanical noise heard coming from the hydrobox.
Heaters switching on/off Normal operation no action required.
Heating mode has been on standby for a long time (does not start operation smoothly.)
Duration is set to excessively short time at “Economy setting for pump”. (Go to “Service menu” → “Auxiliary setting” → “Economy setting for pump”).
Set “Economy setting for pump” longer.
It is essential that the hydrobox is serviced at least once a year by a qualified individual any spare parts required MUST be purchased from Mitsubishi Electric (safety matter).
NEVEr bypass safety devices or operate the unit without them being fully operational.
<draining the hydrobox>
WArNING: drAINEd WATEr MAy bE VEry HoT
. Before attempting to drain the hydrobox islolate from the electrical supply to prevent booster heater burning out.
2. Isolate hydrobox from primary water circuit and drain water from hydrobox. Use a suitable heat resistant hose to assist in these operations.
3. Drain any remaining water from booster heater using fitted drain cock and hose to safely drain the unit.
4. After the hydrobox is drained, water remains in the following component parts. Drain water completely by checking the inside of the parts.
• Strainer (Remove the strainer cover.)
• Pressure relief valve (Operate the valve.)
<Annual maintenance points>
Use the Annual Maintenance Log Book as a guide to carrying out the necessary checks on the hydrobox and outdoor unit.
Code Error Action
L Booster heater overheat detection
Flow rate may be reduced check for;
• Water leakage
• Strainer blockage
• Pump function (Error code may display during filling of primary circuit, complete filling and reset error code.)
L2 Booster heater thermistor (THW3) failure Check the resistance of the thermistor.
L3 Circulation water temperature overheat protection See Action for L.
L4 Tank water temperature overheat protection Check the DHW tank temperature.
L5 Indoor unit temperature thermistor (TH1, TH2, THW1, THW2, THW5B) failure Check the resistance of the thermistor.
L6 Circulation water freeze protection See Action for L.
L7 3-way valve (2-way valve) defective Check the motion of the 3-way valve (2-way valve).
L8 Heating operation error Re-attach any thermistors that have become dislodged.
L9 Low primary circuit flow rate detected by flow switch See Action for L1. If the flow switch itself does not work, replace it.
The pump valves may be hot, please take care.
J0 Communication failure between FTC3 and wireless receiver Check connection cable for damage or lose connections.
J - J8 Communication failure between wireless receiver and wireless remote controller
Check wireless remote controller’s battery is not flat.
Check the pairing between wireless receiver to wireless remote controller.
Test the wireless communication. (See the manual of wireless system) E0 - E5 Communication failure between main controller and FTC3 Check connection cable for damage or loose connections.
E6 - EF Communication failure between FTC3 and outdoor unit
Check that the outdoor unit has not been turned off.
Check connection cable for damage or loose connections.
Refer to outdoor unit service manual.
E9 Outdoor unit receives no signal from indoor unit. Check both units are switched on. Check connection cable for damage or loose connections. Refer to outdoor unit service manual.
U*, F* Outdoor unit failure Refer to outdoor unit service manual.
Note: To cancel error codes please switch system off (Press button E, on Main Controller, for 3 secs).