Mitsubishi Electric PAC-TH011HT-E Installation Manual Download Page 2

Optional parts

D-26

HIGH TEMP. THERMISTOR

4

Optional parts

Heat source

Heating

DHW

Heat pump

Boiler

a) Heating room temperature ( 

 )

FTC4

Boiler

Outdoor unit

b) Heating flow temperature ( 

 )

c) Heating compensation curve ( 

 )

FTC4

Boiler

Outdoor unit

Wireless remote 
controller (option)
or
Room temperature 
thermistor (option)
or
Main controller (remote 
position)

Room thermostat (field 
supply)
or
Wireless remote controller *
(option)

Room thermostat 

* Wireless remote controller can be changed to room thermostat.

1.2 Pipe work

(a) Boiler and heat pump are connected in parallel.
(b) Install a mixing tank (field supply).
(c) Put 2 thermistors in boiler circuit. (THWB1: Flow temp., THWB2: Return temp.)

*  It is recommended to protect the thermistors with heat insulating materials so as not to be affected by ambient temperature.
Note: These lead wires of the thermistors must avoid being in contact with pipe surfaces.

Boiler

Heating

Mixing tank

(field supply)

Cylinder unit/

Hydrobox

Outdoor unit

1

2

3

4

5

6

Boiler

Heating

Mixing tank

(field supply)

Hydrobox

DHW tank

Outdoor unit

1

2

7

8

9

3

4

5

6

Number

Component

1

Boiler flow temp. thermistor (THWB1)

2

Boiler return temp. thermistor (THWB2)

3

Flow temp. thermistor (THW6) (option)

4

Return temp. thermistor (THW7) (option)

5

Circulation pump (field supply)

6

Flow switch (field supply) *1

*1 For safety protection, it is recommended to install a flow switch.

Number

Component

1

Boiler flow temp. thermistor (THWB1)

2

Boiler return temp. thermistor (THWB2)

3

Flow temp. thermistor (THW6) (option)

4

Return temp. thermistor (THW7) (option)

5

Circulation pump (field supply)

6

Flow switch (field supply) *1

7

Tank water temp. (THW5)

8

Immersion heater (field supply)

9

3-way valve (field supply) *2

*1 For safety protection, it is recommended to install a flow switch.
*2  The use of two 2-way valves can perform the same function as a 3-way 

valve.

1. System

1)  Heat source can be switched between heat pump and boiler by external input from power supplier or outdoor temperature 

thermistor.

2) Heat source can be switched according to running cost, CO

2

 emission, or outdoor temp.

3) In case of outdoor unit failure, backup operation is possible with boiler. *1

*1  When Hybrid is selected as heat source.   

When Dip SW2-5 (Automatic switch to backup heat source operation) is set to ON.

Note: FTC4 can control boiler only in space heating mode.

1.1 Room thermostat connection

IMPORTANT NOTE
Be sure to connect room thermostat to FTC4.
When boiler is running,  the heating operation is regulated by the room thermostat connected to FTC4.

Room thermostat 

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