FSV Reference Guide

A complete reference for Samsung EHS heat pump Field Setting Values. FSVs are installer-level configuration parameters that control temperature limits, weather curves, DHW behaviour, backup heater logic, and more.

What are FSVs?

Field Setting Values (FSVs) are configuration parameters stored in the wired remote controller of Samsung EHS heat pumps. They are typically set by the installer during commissioning and control fundamental aspects of how the heat pump operates. FSVs are organised into five categories, each identified by a number prefix.

Menu 10**: Remote Controller

Controls the upper and lower temperature limits that a user can set on the wired remote controller for each operating mode. Adjusting these lets an installer restrict or expand the temperature range available to the end user.

101*Water Outlet Temp. for Cooling

Sets the allowed range for the target water outlet temperature during cooling mode.

FSV	Description	Unit	Default	Min	Max
#1011	Upper limit	°C	25	18	25
#1012	Lower limit	°C	16	5	18

With default settings, the user can set water outlet temperature between 5–25°C for cooling.

102*Room Temp. for Cooling

Sets the allowed range for the target room temperature during cooling mode.

FSV	Description	Unit	Default	Min	Max
#1021	Upper limit	°C	30	28	30
#1022	Lower limit	°C	18	18	28

Setting a higher room setpoint for cooling may save energy and reduce costs.

103*Water Outlet Temp. for Heating

Sets the allowed range for the target water outlet temperature during heating mode. This is one of the most important FSV groups — it determines what flow temperatures your system can target.

FSV	Description	Unit	Default	Min	Max
#1031	Upper limit	°C	70	37	70
#1032	Lower limit	°C	25	15	37

With default settings, the user can set water outlet temperature between 15–70°C for heating.
For underfloor heating systems, installers often lower the upper limit (e.g. to 45–55°C) to protect the floor from excessive temperatures.

104*Room Temp. for Heating

Sets the allowed range for the target room temperature during heating mode.

FSV	Description	Unit	Default	Min	Max
#1041	Upper limit	°C	30	18	30
#1042	Lower limit	°C	16	16	18

Setting a lower room heating setpoint may save energy and reduce costs.

105*DHW Tank Temp.

Sets the allowed range for the target domestic hot water (DHW) tank temperature.

FSV	Description	Unit	Default	Min	Max
#1051	Upper limit	°C	55	50	70
#1052	Lower limit	°C	40	30	40

A lower DHW setpoint may result in higher heat pump efficiency, but may limit the number of showers before recharging.

Menu 20**: Water Law (Weather Compensation)

Weather-dependent control that automatically adjusts the water outlet temperature based on the outdoor air temperature. This reduces unnecessary energy consumption by lowering the flow temperature when it's warmer outside. Also known as a “weather curve” or “heating curve”.

201*Outdoor Temp. for Water Law (Heating)

Defines the outdoor air temperature range over which the heating water law curve operates. The curve maps between two points: a cold outdoor temp (Point ②) with a high water temp, and a warm outdoor temp (Point ①) with a low water temp.

FSV	Description	Unit	Default	Min	Max
#2011	Lower outdoor temp (Point ②)	°C	-10	-20	5
#2012	Upper outdoor temp (Point ①)	°C	15	10	20

With default settings, the water law curve operates across the outdoor temperature range of -10°C to 15°C.

202*Water Outlet Temp. for WL1 Heat (UFH)

Water law curve target temperatures for WL1 (underfloor heating). At the lower outdoor temp, the system targets the higher water temp; at the upper outdoor temp, it targets the lower water temp.

FSV	Description	Unit	Default	Min	Max
#2021	Water temp at cold outdoor (Point ①)	°C	40	17	65
#2022	Water temp at warm outdoor (Point ②)	°C	25	17	65

203*Water Outlet Temp. for WL2 Heat (FCU/Radiator)

Water law curve target temperatures for WL2 (fan coil units or radiators). Radiators and FCUs typically need higher water temperatures than underfloor heating.

FSV	Description	Unit	Default	Min	Max
#2031	Water temp at cold outdoor (Point ①)	°C	50	17	65
#2032	Water temp at warm outdoor (Point ②)	°C	35	17	65

204*Heating Water Law Selection

Selects which water law curve to use for heating mode.

FSV	Description	Unit	Default	Min	Max
#2041	WL type for heating	—	1 (WL1 — floor)	1	2

Set to 1 for underfloor heating (WL1) or 2 for FCU/radiator (WL2).

205*Outdoor Temp. for Water Law (Cooling)

Defines the outdoor air temperature range for the cooling water law curve.

FSV	Description	Unit	Default	Min	Max
#2051	Lower outdoor temp (Point ①)	°C	30	25	35
#2052	Upper outdoor temp (Point ②)	°C	40	35	45

206*Water Outlet Temp. for WL1 Cool (UFH)

Water law curve target temperatures for cooling via underfloor heating.

FSV	Description	Unit	Default	Min	Max
#2061	Water temp at warm outdoor (Point ①)	°C	25	5	25
#2062	Water temp at cold outdoor (Point ②)	°C	18	5	25

207*Water Outlet Temp. for WL2 Cool (FCU)

Water law curve target temperatures for cooling via fan coil units.

FSV	Description	Unit	Default	Min	Max
#2071	Water temp at warm outdoor (Point ①)	°C	18	5	25
#2072	Water temp at cold outdoor (Point ②)	°C	5	5	25

208*Cooling Water Law Selection

Selects which water law curve to use for cooling mode.

FSV	Description	Unit	Default	Min	Max
#2081	WL type for cooling	—	1 (WL1 — floor)	1	2

209*External Room Thermostat

Configures external room thermostat inputs. When enabled, an external thermostat can control the compressor and water pump based on room temperature demand.

FSV	Description	Unit	Default	Min	Max
#2091	Thermostat #1 (UFH zone)	—	0 (No)	0	4
#2092	Thermostat #2 (FCU zone)	—	0 (No)	0	4
#2093	Remote controller room temp control	—	4	1	4

Set both #2091 and #2092 to 0 to use the wired remote controller for heating/cooling.
Values 1–4 control the relationship between the thermostat signal, compressor, and water pump behaviour during thermo-off periods.
Value 1: compressor controlled only by thermostat. Values 2–4: compressor controlled by thermostat or water law temperature, with different water pump behaviour during thermo-off.
To use external thermostats, set 2-zone control (#4061) to 0.

Menu 30**: DHW (Domestic Hot Water)

Controls all aspects of domestic hot water production including heat pump and booster heater behaviour, tank disinfection, and forced DHW operation.

301*DHW Application

Enables or disables DHW functionality and controls how DHW heating starts and stops.

FSV	Description	Unit	Default	Min	Max
#3011	DHW application mode	—	1 (Yes)	0	2

0 = DHW disabled. 1 = DHW starts based on thermo-on temp, stops at thermo-off temp. 2 = DHW starts on demand, stops at thermo-off temp.
When set to 1: heating starts when tank temp drops to the thermo-on temperature, and stops when it reaches thermo-off temperature.
When set to 2: useful for combination operation where DHW should start immediately when conditions require it.

302*Heat Pump (DHW)

Controls the heat pump’s thermo on/off behaviour during DHW operation and the timing between DHW and space heating.

FSV	Description	Unit	Default	Min	Max
#3021	Max HP temperature for DHW	°C	55	45	55
#3022	Temp diff for HP OFF (relative to max HP temp or set temp)	°C	0	0	10
#3023	Temp diff for HP ON (relative to HP OFF temp)	°C	5	5	30
#3024	Min space heating operation time	min	5	1	20
#3025	Max DHW operation time	min	30	5	95
#3026	Max space heating operation time after DHW	hr	3	0.5	10

#3021 sets the maximum tank temperature the heat pump alone can achieve (with R32 refrigerant). For higher temperatures, the booster heater is needed.
#3022 determines when the heat pump stops: HP OFF temp = max(set temp, #3021) - #3022.
#3023 determines when the heat pump starts: HP ON temp = HP OFF temp - #3023.
#3024–#3026 manage timing when both DHW and space heating are requested simultaneously. The max times only apply during dual-demand; single operation runs until the target is reached.

303*Booster Heater (DHW)

Controls the electric booster heater (immersion) in the DHW tank. The booster heater supplements the heat pump when higher tank temperatures are needed.

FSV	Description	Unit	Default	Min	Max
#3031	Booster heater application	—	1 (On)	0	1
#3032	Startup delay time	min	20	20	95
#3033	Overshoot (temp above set temp for BSH OFF)	°C	0	0	4

In “Economic” DHW mode, only the heat pump is used — the booster heater will not activate.
In “Power” or “Forced” DHW modes, the delay timer is skipped and the booster starts immediately.
The delay (#3032) should be shorter than the max DHW time (#3025). Setting the delay too high can cause very slow DHW heating.
BSH OFF temp = set temp + #3033. BSH ON temp = BSH OFF - 2°C.

304*Disinfection (Legionella Prevention)

Periodically heats the DHW tank to a high temperature to kill legionella and other bacteria. This uses the booster heater to reach temperatures above what the heat pump alone can achieve.

FSV	Description	Unit	Default	Min	Max
#3041	Application	—	1 (On)	0	1
#3042	Day of week (0=Sun, 1=Mon, … 6=Sat, 7=Every day)	day	5 (Fri)	0 (Sun)	7 (All)
#3043	Start time (hour of day)	hour	23	0	23
#3044	Target temperature	°C	70	40	70
#3045	Hold duration (time at target temp)	min	10	5	60
#3046	Max total time allowed for disinfection cycle	hr	8	1	24

The system heats the tank to the target temperature, holds it there for the specified duration, then returns to normal operation.
If the target temperature is not reached within the max time, the cycle ends anyway.

305*Forced DHW Operation

Controls whether forced DHW mode has a timer that automatically ends the operation.

FSV	Description	Unit	Default	Min	Max
#3051	Timer OFF function	—	0 (No)	0	1
#3052	Timer duration	×10 min	6 (60 min)	3 (30 min)	30 (300 min)

306*Solar Panel / DHW Thermostat

Configures solar panel integration for DHW heating.

FSV	Description	Unit	Default	Min	Max
#3061	Solar panel application	—	0 (No)	0	2

Not supported on ClimateHub models (no secondary coil in the DHW tank).
When enabled, the heat pump and booster heater are disabled for DHW; the diverter valve switches to space heating position so heating can continue during solar DHW production.

307*Direction of 3-Way Valve

Sets the default resting position of the 3-way diverter valve.

FSV	Description	Unit	Default	Min	Max
#3071	Default direction	—	0 (Room)	0	1

0 = Room (space heating position). 1 = Tank (DHW position).

308*Energy Metering

Sets the rated capacities of the backup heater (BUH) and booster heater (BSH) for accurate energy consumption calculations on the controller display.

FSV	Description	Unit	Default	Min	Max
#3081	BUH step 1 capacity	kW	2	1	6
#3082	BUH step 2 capacity	kW	2	0	6
#3083	BSH capacity	kW	3	1	6

These values must match the actual heater capacities installed for energy monitoring to be accurate.

Menu 40**: Heating

Controls the heat pump’s space heating behaviour, backup heater operation, external backup boiler, mixing valve, inverter pump, and zone control.

401*Heat Pump (Space Heating)

Configures heat pump priority between DHW and space heating, and the outdoor temperature at which heating stops.

FSV	Description	Unit	Default	Min	Max
#4011	Heating / DHW priority	—	0 (DHW)	0	1
#4012	Outdoor temp for priority changeover	°C	0	-15	20
#4013	Heat OFF outdoor temp (HP stops heating above this)	°C	35	14	35

#4011 = 0 (default): DHW always has priority. DHW and heating alternate according to timers #3025/#3026.
#4011 = 1: Space heating is prioritised, but only when outdoor temp is below #4012.
#4013: Above this outdoor temperature, the heat pump will not run for space heating. DHW continues via the booster heater (BSH) only.

402*Backup Heater (BUH)

Configures the electric backup heater (BUH) built into the hydro unit. The BUH provides supplemental heating when the heat pump alone cannot meet demand, particularly in very cold weather or during defrost cycles.

FSV	Description	Unit	Default	Min	Max
#4021	Application	—	0 (No)	0	2
#4022	BUH / BSH priority	—	2 (BSH)	0	2
#4023	Cold weather compensation	—	1 (Yes)	0	1
#4024	Threshold outdoor temp for BUH	°C	0	-25	35
#4025	Defrost backup temp (BUH activates below this water temp during defrost)	°C	15	10	55

#4021: 0 = disabled, 1 = 2-step (BUH 1 + BUH 2), 2 = 1-step (BUH 1 only).
#4022: 0 = both BUH and BSH can run, 1 = BUH priority, 2 = BSH priority (default). The non-priority heater only runs when the priority one has no demand.
#4023/#4024: When cold weather compensation is enabled, the BUH can only operate when the outdoor temperature is below the threshold. This prevents unnecessary electric heating in mild weather.
#4025: During defrost cycles, if water outlet temperature drops below this value, the BUH turns on to prevent cold drafts from chilled water.
Check the capacity of your electrical supply before enabling both BUH and BSH to run simultaneously.

403*Backup Boiler

Configures an external backup boiler (e.g. gas or oil) that can take over heating when outdoor temperatures are extremely low.

FSV	Description	Unit	Default	Min	Max
#4031	Application	—	0 (No)	0	1
#4032	Boiler priority	—	0 (No)	0	1
#4033	Threshold outdoor temp	°C	-15	-20	5

When the outdoor temperature drops below #4033, the heat pump stops and the external boiler takes over completely.
The heat pump resumes when outdoor temp rises to #4033 + 3°C.
The external boiler must be capable of autonomous operation (zone control, pump control) during backup mode.

404*Mixing Valve

Configures an optional mixing valve installation, typically used with underfloor heating to blend high-temperature water down to a safe floor temperature.

FSV	Description	Unit	Default	Min	Max
#4041	Application	—	0 (No)	0	2
#4042	Target ΔT for heating	°C	10	5	15
#4043	Target ΔT for cooling	°C	10	5	15
#4044	Control factor (higher = faster response)	—	2	1	5
#4045	Control interval	min	2	1	30
#4046	Running time	×10 sec	9 (90 sec)	6 (60 sec)	24 (240 sec)

#4041 = 1: Controlled based on the temperature difference set by #4042/#4043.
#4041 = 2: Controlled based on the water law target temperature difference.
Higher #4044 and lower #4045 = faster response. But too-fast control may cause temperature fluctuations depending on the heating load.

405*Inverter Pump

Configures the built-in variable-speed circulation pump. The pump adjusts its speed to maintain a target temperature difference (ΔT) between inlet and outlet water.

FSV	Description	Unit	Default	Min	Max
#4051	Application	—	1 (Yes)	0	2
#4052	Target ΔT	°C	5	2	8
#4053	Control factor	—	2	1	3

#4051 = 1: Inverter pump enabled at 100% max output (default).
#4051 = 2: Inverter pump enabled at 70% max output. Use when flow is too high, though this is typically a system design issue that should be fixed with balancing valves.
#4051 = 0: Inverter pump disabled.
#4052: The pump adjusts speed to maintain this temperature difference between inlet (Tw1) and outlet (Tw2).

406*Zone Control

Enables 2-zone control via the wired remote controller, allowing independent control of two heating/cooling zones (e.g. underfloor + radiators).

FSV	Description	Unit	Default	Min	Max
#4061	Application	—	0 (No)	0	1

To use zone control, set #4061 to 1 and disable external thermostat control (#2091 and #2092 = 0).
Zone control uses the wired remote controller as a room sensor — it does not use external thermostat signals.
Zone 2 has priority for operation modes and discharge water temperature.
Not supported on MIM-E03CN control kit. Supported on MIM-E03EN.

Menu 50**: Others

Miscellaneous settings including outing/holiday mode temperatures, DHW energy saving, power peak control, frequency ratio limiting, PV panel integration, and smart grid control.

501*Outing (Holiday) Mode

Sets the target temperatures for all modes when the system is placed into outing/holiday mode. These are typically set lower than normal to save energy while preventing freezing.

FSV	Description	Unit	Default	Min	Max
#5011	Water outlet temp for cooling	°C	25	5	25
#5012	Room temp for cooling	°C	30	18	30
#5013	Water outlet temp for heating	°C	15	15	55
#5014	Room temp for heating	°C	16	16	30
#5015	Auto cooling WL1 temp	°C	25	5	25
#5016	Auto cooling WL2 temp	°C	25	5	25
#5017	Auto heating WL1 temp	°C	15	15	55
#5018	Auto heating WL2 temp	°C	15	15	55
#5019	Target tank temp (DHW)	°C	30	30	70

502*DHW Saving

Energy-saving mode for DHW that lowers the target tank temperature. Activated via the “Eco” mode on the wired remote controller.

FSV	Description	Unit	Default	Max
#5021	Temperature reduction from user setpoint	°C	5	40
#5022	DHW saving mode	—	0	1
#5023	Thermo-on temp in saving mode	°C	25	40

Example: if user sets DHW to 45°C and #5021 = 5, the actual target becomes 40°C in eco mode.
#5022 = 0: saving mode uses the reduced temperature. #5022 = 1: additional saving with different thermo-on control.

504*Power Peak Control

Allows an external signal (e.g. from a power company) to force certain components off during grid peak demand periods. The signal is applied via a digital input.

FSV	Description	Unit	Default	Max
#5041	Application	—	0 (No)	1
#5042	Select forced-off parts	—	0 (All heaters off)	3
#5043	Input voltage type	—	1 (High)	1

#5042 controls which components are forced off when the signal is active:
0 = Compressor permitted, BUH forced off, BSH permitted.
1 = Compressor permitted, BUH forced off, BSH forced off.
2 = Compressor forced off, BUH forced off, BSH permitted.
3 = Compressor forced off, BUH forced off, BSH forced off (everything off).
#5043 = 1 (default): high voltage signal triggers peak control. Set to 0 to invert (low signal triggers).
If the system is off for more than 60 minutes due to peak control, use glycol in subzero conditions to prevent freezing.

505*Frequency Ratio Control

Limits the maximum compressor frequency of the outdoor unit. Can be controlled by a 0–10V DC signal or via Modbus communication. Also known as “Demand Ratio” (DR) on the controller display.

FSV	Description	Unit	Default	Min	Max
#5051	Application	—	0 (Disable)	0	1

When enabled, an external 0–10V signal controls compressor frequency: 0V = 50% of max, 5V = 100%, 10V = 150%.
Can also be controlled via Modbus communication for building management system integration.
The actual frequency is still bounded by the normal min/max Hz limits for the current outdoor temperature.

506*Heat/DHW Capacity Ratio

Controls the capacity ratio between space heating and DHW operations.

FSV	Description	Unit	Default	Min	Max
#5061	Heat/DHW capacity ratio	—	—	—	—

508*PV Control (Photovoltaic)

When a solar PV panel system signals that excess energy is available, the heat pump can take advantage by shifting setpoints to store more thermal energy. Shares the same input contact as Power Peak Control, so they cannot both be used.

FSV	Description	Unit	Default	Max
#5081	Application	—	0 (No)	1
#5082	Temp shift for cooling	°C	1	5
#5083	Temp shift for heating	°C	1	5

Except for DHW mode, this function only activates during outing mode.
Cooling: setpoint is lowered by #5082. Heating: setpoint is raised by #5083. This encourages the system to run harder while free solar energy is available.
DHW: targets max temperature (#1051) regardless of outing mode.
Cannot be used simultaneously with Power Peak Control (#504*) as they share the same input.

509*Smart Grid Control

Advanced grid-interactive control using two digital inputs providing four operating modes. Allows power companies to remotely adjust system demand based on grid conditions — both reducing demand during peak load and increasing it when excess grid capacity is available.

FSV	Description	Unit	Default	Min	Max
#5091	Application	—	0 (No)	0	1
#5092	Temp shift for heating (step-up)	°C	2	2	5
#5093	Temp shift for DHW (step-up)	°C	5	2	5
#5094	DHW mode for Mode 4	—	0	0	1

Mode 1 (Signal 1 short, Signal 2 open): Forced thermo-off of all systems.
Mode 2 (both open): Normal operation.
Mode 3 (Signal 1 open, Signal 2 short): 1 step-up — heating setpoint raised by #5092, DHW by #5093.
Mode 4 (both short): 2 step-up — heating raised by #5092 + 5°C (water) or + 3°C (room). DHW: #5094 = 0 targets 55°C (HP only), #5094 = 1 targets 70°C (HP + BSH).

Important notes

This guide is based on the Samsung EHS Mono Tank Integrated Type installer reference manual. Default values may vary depending on your specific model.
FSV changes should only be made by a qualified installer who understands the implications for your specific system configuration.
Some FSV codes (e.g. #503* TDM Variable) are only relevant to specific product types and are not covered here.