Kwikot Commercial Series User manual

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Commercial Series
Air Source Heat Pump Water Heater
Instruction Manual
Model: GT-SKR030P
GT-SKR050P
GT-SKR070P
GT-SKR100P
GT-SKR150P
GT-SKR030B (commercial unit )
GT-SKR050B
◆The instructions in this manual are for the use of qualified individuals specially
trained and experienced in the installation and maintenance of this type of equipment.
◆ Persons not qualified shall not attempt to install, service, or maintain this equipment.
◆Please read the manual carefully before installation.
◆Please keep this manual well for future reference.

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TABLE OF CONTENTS
Part I: General Information···············································································································3
Part II: Application & Installation······································································································6
Installation Location requirement·····························································································6
Installation illustration···············································································································7
How to open the front panel·····································································································8
Install the unit···························································································································8
Electrical connection················································································································9
How to relocate the control panel····························································································10
Trial operation··························································································································11
Part III: Control System······················································································································13
Lock/Unlock the buttons···········································································································13
On/Off the unit··························································································································13
Set the clock·····························································································································14
Set water tank temperature ······································································································14
Set/Review/Cancel the timer of On/Off······················································································14
Set//Review/Cancel the timer of water supply···········································································14
Manually control water supply···································································································15
Set the parameters····················································································································15
Data review ·······························································································································15
Part IV: Maintenance····························································································································17
Part V: Trouble shooting······················································································································18
Part VI: Wiring diagram························································································································20

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Part I: General Information
1.1 Function description
Air source heat pump water heaters are used to make hot water for space heating, domestic hot water
systems or commercial hot water systems.
1.2 Important Information
For your own security, and to ensure proper operation of the unit, this heat pump unit must be
installed and repaired by qualified technician, not consumer himself.
A leakage protection switch must be installed near the heat pump in an accessible place.
Do not use any damaged wires and switches, If found ( to be damaged), replace it immediately.
Do not open the electrical box without shutting off all power sources to the heat pump.
When transporting the heat pump, ensure that it is not upside down and not tilted more than 45°
in any direction.
Before performing any maintenance on the heat pump you must swith it off first and shut off the
power to the unit.
This unit is designed for outdoor installation, do not install it in an enclosed area.
Do not install the unit in places where there are any inflammable or explosive materials.
Do not restrict or block the area around the air intake or outlet.
When the unit is not used for a long time, please switch it off and disconnect the power supply.
Drain the unit when ambient temperature is lower than 0℃.
When power failure occurs and lasts for more than 3-5 hours with the ambient temperature ≤
2℃, please drain water to prevent the formulation of ice in the unit.
This appliance is not intended for use by persons (including children) with reduced physical,
sensory or mental capabilities, or lack of experience or knowledge, unless they have been given
supervision or instruction concerning use of the appliance by a person responsible for their safety.
Respect safety distance between the unit and other equipment or structures. Guarantee adequate
space for access to the unit for maintenance and/or service operations.
Power supply: the cross section of the electrical cables must be adequate for the power of the unit

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and the power supply voltage must correspond with the value indicated on the respective units. All
units must be earthed in conformity with legislation in force in the country concerned.
1.3 About heat pump
Heat pumps are effective solutions to heating and cooling applications for all types of buildings, domestic,
commercial and retail premises including hotels and residential complexes.
This well-proven technology has been in use for decades and Heat Pumps are at work all over the world
providing safe, reliable heating and cooling at affordable prices.
Reserves of conventional fossil fuels are finite and emissions of Carbon Dioxide and other greenhouse
gases add increasingly to the effects of climate change.As a low carbon technology, heat pumps can
significantly reduce the Carbon Dioxide emissions.
Where Heat Pumps are used for heating, they are capable of highly cost-efficient energy applications
because they tap into a limitless supply of clean, pollution-free heat – either the surrounding air or heat
captured in the ground – all you pay for is the energy to transport that heat, so the fact is heat pumps supply
more energy than they consume.
1.4 Working principle
The basic principle of how a air source heat pump works is simple. It works just like air conditioner in
cooling mode, however, in heating mode, the refrigerant flow is reversed and heat is extracted from the
outside air to heat air or water. So the purpose of a heat pump is to absorb heat in one place where it is
plentiful, then to transport and release it in another location where it can be used for space or water heating.
In order to absorb and release the heat into and from the refrigerant, we exploit the ability of the refrigerant
fluid to boil from a liquid to a vapor and then to condense back into a liquid. This is a continual process while
the compressor is running and circulating the refrigerant.
1. The refrigerant in system extracts free heat energy from ourside air through fin-coil evaporator.
2. The refrigerant is compressed to a high-temp. & high-pressure gas by compressor.
3. Heat energy transferred to water through tube-in-shell heat exchanger.
4. The refrigerant in system restores to low-energy condition
5. The cycle is repeated.

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1.5 Features of heat pump water heater
1）Wide application
It can be widely used in villas, factories, schools, hospitals, hotels, restaurant, swimming pools and spas,
bath centers, laundries, etc.
2）More Safety
Water and electricity are completely isolated, No electric shock problem, more secure than traditional
electrical water heaters.
No fuel tubes and storage, no potential danger from oil leakage, fire, explosion, etc.
a full range of protection including compressor delay protection, duel pressure protection, overheating
protection, Anti-phase and open-phase protection, high temperature protection, etc.
3）Energy-saving
Provide the same amount of hot water at 1/4 cost of electrical water heaters, heat pump water heater unit
can save your bill every day.
4）Super-Sized evaporator coil
It adopts hydrophilic aluminum fin and rifled copper pipe.
5）High efficiency heat exchanger
It adopts high efficiency tube-in-shell heat exchanger.
6）World famous Compressor
It adopts the world famous brand compressor---“Copeland”, “Panasonic”, “Sanyo”, “Toshiba”, unmatched
reliability, quiet operation, energy-saving and environmental-friendly.
7）Monoblock design, convenient installation, nice appearance.
8）All-weather running
Reliable hot water offer no matter in a rainy day, snowy day or at night.
9）Running automatically
Micro-computer controlled, with timer function, it can automatically start up and stop according to the water
temperature and other running conditions you set, no need for a supervisor.
10）Environmental friendly
Environment-friendly, free of pollutions, it reduces the global green house effect.

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Part II Installation &Application
2.1 Transportation
When transporting the heat pump, ensure that it is not tilted more than 45°in any direction.
The unit in its case can be transported with a lift truck or hand truck.
2.2 Accessories
Remove the packaging, be careful not to damage any components.
No Item Quantity
1 Instruction Manual 1
2 Condensate connector 1
3 Shockproof rubber pads 1 set
2.3 Installation Location Requirement
This unit is designed for outdoor installation, please do not install it in an enclosed area.
It is very important to select a proper position for the unit, please consider the followings:
■ Choose a horizontal position where it can stand the weight of the unit, and it won’t increase noise and
vibration as well, preferably on a concrete slab. And the supporting base must be high enough to keep
unit completely free of standing water at all times.
■ Do not install the unit within 1000mm of fossil fuel burning heaters. Air intakes along the sides of the
heat pump unit could disturb the combustion process of the unit and cause damage or personal injury.
■ Choose the place with good ventilation and not close. The minimum distance between the wall (or other
objects) and the sides of the unit where the air comes in should not be less than 1000mm.(see figures
below)
■ Do not install the unit in place where there is pollution, corrosive gas, or accumulation of dirt or fallen
leaves.
■ There should not be inflammable or explosive materials close to the unit.
■ Keep in mind that the heat pump will cause condensation, so the installation position should be close to
drainage channel or vent to facilitate water discharge.
min 1000mm
from the
above
min 2000mm
air exhale
air inhale
air inhale
min 1000mm min 1000mm
min 1000mm
air inhale
min 1000mm
min 1000mm
min 1000mm
min 2000mm
air exhale
air inhale
air inhale
air exhale

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2.4 Installation
2.4.1 Installation Illustration for Heat Pump Water Heater (take vertical ventilation series
for example)
Note:
1. "Water refill": add city water into water tank;
"Water supply": supply hot water from water tank to user;
"water return ": when water temp. in pipes of user's system is lower than the temperature you set, water
in pipes will return back to water tank through "water return magnetic valve", so water in the pipes is
always hot. When there is no need for "water return " function, users do not need to install "water return
magnetic valve" & "water return temp. sensor".
2. "Water refill pump": When water pressure of city water is very low or not stable, it is suggested to install
a "water refill pump". The power supply for "Water refill pump" and "Water refill magnetic valve" are
synchronized.
3. "Circulating pump": It is suggested to install extra AC contractor when the power of "circulating pump"
and "water refill pump" are more than 500W respectively.
4. The hot water outlet of water tank which connects to user's hot water system must be higher than the
water inlet of heat pump unit in order to avoid lack of water for the unit.
5. Water level: Users can adjust the high water level and low water level according to their actual needs.
6. When water tank is pressurised type, there is no need to install magnetic valve and high/low
water level switches.
a
a
a
valves for cleaning
or anti-freezing
Magnetic valve
Equal tee
Union
Wye strainer
Check valve
Water pump
Gate valve
Legend
This part of water supply
is for reference only
Unpressurized
Water Tank
Electirical
Heater
connection
5cm
Water Outlet
Heat Pump
Water Inlet User's hot
water system
City water
Temp. sensor
connection
High water
level point
Low water
level point

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2.4.2 How to open the front panel
2.4.3 Install the unit (take vertical ventilation series for example)
a. Choose a smooth, horizontal position according to the Location Requirement.
b. The vertical distance between the unit and water tank must be less than 6m, and their horizontal distance
should not be more than 20m. But the actual distance is determined by the capacity of circulating water.
pump.
c. Mount the unit on the selected base and install
the 4 black rubber pads under the 4 corners of
the unit to reduce vibration and sound
transmission to the base. (see figure right)
d. Fix the tank. If the tank is installed on the roof,
you should install a lightning rob for fear of the
lightning strike.
e. Connect the water pipes between heat pump
and tank according to Installation Illustration.
f. Install the check valve as arrow shows.
g. Make sure to Install Y strainer as shown on the
installation illustration to prevent the circulating
system from being clogged.
Base Rubber pad 4pcs
front sheet
screw
vertical distance
total pipe run (water in + water out), horizontal≤20m
Water Tank
Heat Pump Heat Pump
Water Tank
≤6

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h. Fix the tank temperature sensor well to prevent it
from dropping down. Otherwise, it may cause an
action of overheat protection or crash. (See figure
right and its Note)
i. Installation of condensate connector: Connect the
connector at the bottom of the main unit. (See figure
below)
j. Install the water level switches of water tank, then
connect the wire to “terminal block of control signal”
(see wiring diagram). Or Users could control the
water level by other means, such as ball float valve.
2.4.3 Electrical Connection
●For your own security, and to ensure
proper operation of the unit, this heat pump
unit must be installed and repaired by
qualified technician, not consumer himself.
●A leakage protection switch must be
installed near the heat pump in an
accessible place.
●Do not use any damaged wires and
switches, If found ( to be damaged), replace it
immediately.
●Do not open the electrical box without
shutting off all power sources to the heat
pump.
m".
zAll the wiring must meet the electrical safety
requirement and conducted by qualified electricians.
zEnsure that there is a good earth connection for the power. Do not disconnect the earth connection of
the power in any condition.
zEnsure that the heat pump water heater is well connected to the earth.
zOffer an separate power which meets rated requirements for the heat pump water heater
zWhen the water heater connects to the electricity network, there must be a short-circuit protection.
zChoose the suited type of wires when use the power outdoor.
zDo not use the main power switch to control the start/stop of the unit.
zAfter installation, double check before connect it to the power.
Condensate
connector
Front
Note:
1. Do not put the probe directly into water.
2.Just leave the “water return temp. sensor”
at there when users do not choose
“water return” function.
Front
Condensate
connector
water tank
temp. sensor
water return
temp. sensor
CNBA
PCB

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(Take Vertical Ventilation Series for Example)
2.4.5 How to relocate the control panel
open the control panel
push
When you need to relocate the control panel, please refer to the following:
cable exit
Put the wire through the cable exit ,
then relocate the control panel to a proper place.
Note:
When install the control panel out of the unit,
a.Keep it away from rain. Waterproof well.
b.Make sure children cannot touch it.
c.Do not install it in bathroom.
AB NC
waterproof box
Power Connection
CNBA
AB N
C
PCB
leakage
protection
switch
Power
switch
Electricity grid

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2.5 Trial Operation
To ensure that start-up is performed correctly, it should only be operated by qualified technician.
2.5.1 Preparation
The following items need to be checked prior to start-up:
a).The heat pump must be fully connected.
b).All valves that could impair the proper water flow in piping system must be open.
c).The air intake and air outlet paths must be clear.
d). Discharge the air in the suction pipe of the water pump.
For horizontal ventilation series, circulating water pump is installed inside the unit. It’s essential
to discharge air out of piping system as well as the water pump.
Open the gate valve to fill up the piping system and water tank, then discharge air in piping system and
water tank (refer to the following instruction)
□ To discharge air in water pump and piping system:
Step1: loosen the screw on the water pump through the hole,
Step2: open water refilling gate valve to let the city water in,
Step3: after the air is completely discharged, fasten the screw.
e). Ensure the condensate outflow functions.
f).The heat pump controller must be set in accordance with the controller’s operating instructions. ( Refer
to Part III Control System)
2.5.2 Trial running
● The water outlet temperature is set by the controller. When the water temperature of the tank is higher
than it is set, the unit will stop running, but if lower by 5℃(default temperature difference), it may restart
automatically.
● Turn on the power, The heat pump is started up via the heat pump control panel. After the water pump
have been running for 30 seconds, the unit starts to work, and then observe whether it works normally.
● When you restart the unit, the compressor won’t start to work until 3 minutes later, and this delay
function is designed to protect the compressor.
loose the screw by a flat blade screwdriver
It’s very important
to discharge air!
Airdischarge of water pump
Air discharge of water pump

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2.5.3 Caution
If something happen as follows, please stop it immediately and cut the power off. You should contact with
our authorized agent or maintenance personnel. Do not repair it by yourselves. Without professional
technology, it may cause fire and you may get hurt.
● Fuse blown or protection device breaks frequently
● The wire and switches are heated singularly
● Abnormal sounds coming from the unit
● Abnormal smell comes out of the unit.
● Electricity leakage

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Part III Control System
3.1 Overview
The controller consists of PCB and operation panel and it makes the unit more automatically for it can
not only meet the internal control requirements, but also helps to control the external apparatus.
Meanwhile, it can be easily set after it leaves the factory. And it becomes one kind of popular and
advanced integrated controllers for its great integrated functions and its large screen operation panel.
3.2 Description of Icons
3.3 Operation Instruction
OFF ON Compressor starts running
A. Lock/Unlock the buttons
1. Lock the buttons: Under ON or OFF status, extended press button simultaneously for 5
seconds, buttons are locked, and icon is shown on the screen.
2. Unlock the buttons: Repeat the above step to unlock the buttons
B. On/Off the unit
⑴Icon Flashes when compressor starts running
⑵Defrosting indication
⑶Icon shows when the unit starts running
⑷Auxiliary electrical heating indication (optional)
⑸The desired water temperature
⑹The clock
⑺Water level indication
⑻ Measured water tank temperature
⑼ Timer of turning-on the unit
⑽ Timer of turning-off the unit
⑾ Water supply

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1. Connect power to the unit, press button to turn on the unit (see picture ON ), When compressor
starts working, icon flashes on screen (see picture Compressor starts running)
2. When the unit is on, press button, you can turn it off (see picture OFF).
C. Set the clock
Under ON or OFF status, extended press button for 5 seconds, then press button to
set the hour, press button, then press button to set the minute, press button to
exit setting.
D. Set water tank temperature
When the unit is on, press button to set desired water tank temperature. The setting will be
saved automatically when no further operation on it for 10 seconds. The range is 28-60 degrees Cel.
Note:
·Heat pump unit will stop running automatically when water tank temperature reaches desired water
temperatureyouset.
·The unit will start running automatically when water temperature drops to a certain temperature.
( according to temperature difference you set, refer to item 05 in table 3.1 below)
E. Set/Review/Cancel the timer of On/Off
Note:
You can set totally three periods of time for the unit to start/stop. Under ON or OFF status, Press
button once, “ 1 ” flashing on the screen; Press button twice, “ 2 ” flashing on the screen;
Press button thrice, “ 3 ” flashing on the screen. And the cycle is repeated when you continue
pressing button.
1. Set timer: (Take “ 1 ” for example)
when “ 1 ” is flashing, Press button, flashing on the screen, then press
button to set the hour, press button，then press button to set the minute, press
button, flashing on the screen, then press button to set the hour, press
button，then press button to set the minute, press button to finish setting. The
setting will be saved automatically when no further operation on it for 10 seconds.
2. Cancel timer: To cancel timer, just set the unit to turning-on & turning-off at the similar time, then
icon disappeared.
F. Set//Review/Cancel the timer of “Water Supply”
Note:
You can set totally three periods of time for the unit to supply water automatically. Under ON or OFF
status, extended press button for 5 seconds to enter the interface, icon flashes. “ 1 ” flashing
on the screen; Press button twice, “ 2 ” flashing on the screen; Press button thrice, “ 3 ”
flashing on the screen, and the cycle is repeated when you continue pressing button.
1. Set timer: (Take “ 1 ” for example)
when “ 1 ” is flashing, Press button, flashing on the screen, then press

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button to set the hour，press button，then press button to set the minute, press
button, flashing on the screen, then press button to set the hour, press
button，then press button to set the minute, press button to finish setting. The
setting will be saved automatically when no further operation on it for 10 seconds.
2. Cancel timer: To cancel timer, just set the unit to turning-on & turning-off at the similar time, then
icon disappeared.
G. Manually control “Water Supply”
When water tank temp. reaches the temp. you set, Press button, you can manually control water
supply, icon flashes on the screen.
H. Set the parameters (for technician only)
When the unit is on, extended press button for 5 seconds to enter the interface. press
button, select item (01-08), press button, then press button to set, press button
to confirm. The setting will be saved automatically when no further operation on it for 10 seconds.
Table 3.1
Item Description Range Default Value Remark
01 Coil temp. to start defrosting -1～-9℃-3℃flashing
02 Coil temp. to stop defrosting 5～25℃12℃flashing
03 Time interval for defrosting 10～90 Min 45 Min flashing
04 Running time of defrosting 5-17 Min 10 Min flashing
05 Temperature difference set 2-30 9 Refer to note 1,2,3 as below
06 Temp. compensation 0-30 0
07 Water return temperature 28～60℃40℃flashing, it’s for commercial unit.
08 Ambient temp. for starting
electrical heating
0～35℃5℃flashing, when ambient temp. is
lower than set temp. , electrical
heating functions.
Note:
1.Set the temperature difference between the measured water temperature and desired water
temperature
2. By setting the temperature difference users can control the unit to starts up/stops automatically.
3. For example, the default value is 9 (that represents 5℃), when the measured temperature is lower
than desired water temperature by 5℃, the unit will start automatically. The unit will not stop until the
measured temperature reaches the desired water temperature you set.
1 equals 0.5℃, the range is 2-30.
I. Data Review
When the unit is on, shortly press button to enter the interface. press button, review the

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actual measured data as below，press button to exit.
Table 3.2
Name Item Remark
Code of recoverable fault 01 It shows “28” when it works normally, others please refer to Table
3.3
“Mode Selection" Code
Name 02 “00” timed water supply mode, “01” Direct water supply “02” Double tank water-supply mode (Apply to the double
compressor system only)
Unit type
03
“00” 220V, 030P, No phase detection, single compressor
“01” 380V, 030P/050P/070P, with phase detection, single
compressor
“10” 380V, 100P,150P with phase detection, double compressor
Coil 2 temperature 04 Monitoring point of Defrosting temp. for compressor 2 (for double
system)
Coil 1 temperature 05 Monitoring point of Defrosting temp. for compressor 1
Ambient temperature 06 Opening measurement of the electric expansion valve, and the
anti-freeze temperature
Water outlet temperature 07 overheating protection (70℃)
Water return temperature 08 Check the water temperature in the supply pipes and control the
return water temperature
Water temperature in tank 1 09 temperature of water tank 1
Unused 10 Spare
Unused 11 Spare
Table 3.3 Recoverable faults
Fault Name Remark
“01E” Overheat protection Hydraulic pressure switch protection
“05E” Overheat protection If the water outlet temperature is higher than 70℃and lasts
for 20 seconds, the unit may stop. And when the temperature
cools down, it will restart in three minutes.
3.4 Protection
◆Compressor delay protection: the delay for the compressor to start/stop is three minute. The first time
when it is power on, it starts up in one minute.
◆High pressure protection: After compressor starts running and the high pressure switch interrupts for
10 seconds, the unit stops, “03E” flashing on the screen, and alarm sounds.
Low pressure protection:◆After compressor starts running for 3 minutes and the low pressure switch
interrupts for 10 seconds, the unit stops, “04E” flashing on the screen, and alarm sounds.
◆When hydraulic pressure switch interrupts, the unit stops, “01E” fault code is shown on the screen and
it won’t alarm. When the pressure recovers, the unit restarts automatically.
◆Overheating protection: when water outlet temperature is higher than 70 for 20 seconds, the℃
compressor stops, and when the temperature cools down to where it is set and the unit meets the
condition of stopping for three minutes, the unit restarts automatically,
◆Sensor fault: if the sensor fault, all parts stop working (except the electric heating device)
◆Anti-phase protection and Open-phase Protection: all the components are not allowed to work, and

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fault code is shown on screen.
◆Auto-antifreeze: To prevent the pipes and pumps from being frozen, the unit will defrost automatically
when it meets the condition as follows: the ambient temperature is lower than 2 and℃the water outlet
temperature is lower than 10℃and the circulating pump has been power off for more than 30 minutes.
The circulating pump start up for 60 seconds and then turn off. And this action is repeated periodically.
◆Check the current when the unit starts up and if the current is stronger than the default current for 5
seconds the unit will shut down immediately and restart 3 minutes later. but if the same fault appears
more than 3 times in an hour, the unit will alarm. The fault code is “02E”.
Part IV Maintenance
Before performing any maintenance on the heat pump you must switch it off first and shut off the power
to the unit.
A well-maintained heat pump could save your energy costs. When installed and tested by a qualified
technician, heat pumps can deliver many years of dependable service and comfort. Below are some
steps you can follow to ensure that your heat pump gives you optimum performance.
1. Turn the power off when the unit is being maintained.
2. Do not use petrol, naphtha, dissolvent and any other chemicals on the unit, otherwise, it may damage the
surface. External heat pump parts can be wiped with a damp cloth and domestic cleaner.
3. Avoid leaning or putting objects on the device.
4. Keep it dry and drafty round the unit.
5. If the unit will be shut down for a long time, you should drain the water in the pipe, turn the power off and
cover it with protective cover, Check it roundly before you start it again.
6. It is advised to use the phosphoric acid whose temperature is about 50～60℃and consistency is 15% to
clean the heat exchanger of the unit. First start the circulating pump to clean it for 3 hours, and then flush
it with tap water for three times. Do not use any amyctic detergent to clean the heat exchanger and the
tank.
7. Change the installation site
If the customer wants to change the site, please contact with the dealer or the local Customer Service for
help.

- 18 -
Part V Trouble shooting
Table 3
Fault
Code
Fault Possible Causes Treatment
00E Open-phase protection
Anti-phase protection
◇Open-phase
◇Anti-phase
◇Check the three-phase power supply
◇Exchange wirings of two phases
01E Hydraulic pressure
switch protection
◇Hydraulic switch destroyed
◇Inadequate water-flow
◇There is air in the circulating water inlet tube
◇Circulating pump destroyed
◇Water tank lack of water
◇Replace the hydraulic switch
◇Clean Y strainer, increase the water flow rate
◇Discharge the air
◇Check and repair the pump and the capacitor
◇Ensure the tank is fully filled and the water pressure is
over 0.15Mpa
02E Current protection ◇Current excessive ◇Check the voltage and the power source
03E High pressure switch 1 fault
(protect when interrupts)
◇High pressure switch destroyed
◇Inadequate water-flow
◇The system is jammed, the probe of sensor falls down
◇circulating pump damaged
◇excessive refrigerant
◇some incondensable gas in the refrigerant system
◇Replace the high pressure switch
◇Increase the flow
◇Check and clean the system, retighten the probe
◇Check and repair the circulating pump and the capacitor
◇Drain out the superfluous refrigerant
◇Drain out the incondensable gas
04E Low pressure switch 1 fault
(protect when interrupts)
◇Low pressure switch destroyed
◇Inadequate refrigerant
◇The fins of the evaporator are dirty
◇Replace the low pressure switch
◇Leak hunting and fill in standard quantity of refrigerant
◇Clean the fins
05E Overheating of the outlet water ◇Clogged water line
◇water outlet temperature sensor fault
◇Check the water system and the pump
◇Check the resistance of the sensor
06E Water level switch destroyed
(closes at high water level,
interrupts at low water level)
◇Open/short circuit in the switch and wires ◇Check and renovate the switch and its wiring
07E High pressure switch 2 fault
( fault when interrupts)
◇High pressure switch destroyed
◇inadequate water-flow
◇Replace high pressure switch
◇Increase water-flow
08E Low pressure switch 2
fault( fault when interrupts)
◇Low pressure switch destroyed
◇Inadequate refrigerant
◇Replace low pressure switch
◇Leak hunting and fill in standard quantity of refrigerant
09E Communication error
( the control panel can’t receive
information from the PCB)
◇Open circuit or short circuit between the operation
panel and PCB
◇Renovate or Replace the wire between the control panel
and the PCB
10E Coil sensor 2 fault
(open circuit or short circuit)
◇The sensor open circuit
◇The probe of the sensor falls down
◇the sensor short circuit
◇Reconnect the wirings of the sensor
◇Retighten the probe
◇Renovate wirings
11E Coil sensor 1 fault
(open circuit or short circuit)
◇The sensor open circuit
◇The probe of the sensor falls down
◇the sensor short circuit
◇Reconnect the wirings of the sensor
◇Retighten the probe
◇Renovate wirings
12E Environment sensor
fault (open circuit or short
circuit)
◇The sensor open circuit
◇The probe of the sensor falls down
◇the sensor short circuit
◇Reconnect the wirings of the sensor
◇Retighten the probe
◇Renovate wirings

- 19 -
13E Water outlet sensor
fault (open circuit or short
circuit)
◇The sensor open circuit
◇The probe of the sensor falls down
◇the sensor short circuit
◇Reconnect the wirings of the sensor
◇Retighten the probe
◇Renovate wirings
14E Water return sensor
fault (open circuit or short
circuit)
◇The sensor open circuit
◇The probe of the sensor falls down
◇the sensor short circuit
◇Reconnect the wirings of the sensor
◇Retighten the probe
◇Renovate wirings
15E Water-tank sensor 1
fault (open circuit or short
circuit)
◇The sensor open circuit
◇The probe of the sensor falls down
◇the sensor short circuit
◇Reconnect the wirings of the sensor
◇Retighten the probe
◇Renovate wirings
Note: when the fault arises, the correspondent fault code will be flashing on the screen and alarm sounds.
Table 4
Fault Condition Possible Causes Treatment
The unit doesn’t work
◇Power failure
◇Bad connection to the power
◇Fuse blow
◇Turn off the switch, check the Power source
◇Find the causes and renovate them
◇Replace the fuse
The pump is working but too noisy and
the water is not cycled
◇Lack water In the system
◇There is air in the water circulation
◇Any valve in the system is not open
◇Filter stoppage
◇Check the water refill device and
refill water
◇Discharge the air
◇Open all the valves
◇Clean the filter
Low heating capacity
◇Inadequate refrigerant
◇bad insulation of the water system
◇Drying filter stoppage
◇Air side heat exchanger is un-efficient
◇Inadequate water-flow
◇Leak hunting and fill in standard
quantity of refrigerant
◇Improve the heat insulation
◇Replace the drying filter
◇Clean the heat exchanger
◇Clean the water filter
The compressor doesn’t work
◇Power failure
◇Compressor contactor destroyed
◇Poor connection
◇Overheating protection
◇water outlet temperature is too high
◇Inadequate water-flow
◇Check it and solve the problems
◇Replace contactor
◇Check and renovate it
◇Check and solve the problems
◇Reset a proper temperature
◇Clean the water filter and discharge the air in the water
system
The compressor works but too noisy
◇Liquid refrigerant goes into the compressor
◇interior components destroyed
◇Inadequate refrigeration oil
◇Check the expansion valve
◇Replace the compressor
◇Add in adequate refrigeration oil
The fan doesn’t work
◇Capacitor damaged
◇The fans are not fixed well
◇The electromotor burned out
◇Contactor destroyed
◇Replace it
◇Fix it well again
◇Replace the electromotor
◇Replace the Contactor
Compressor works but not heating
◇Refrigerant leakage
◇Compressor fault
◇Leak hunting and fill in standard quantity of refrigerant
◇Replace it
Low water-flow protection ◇Hydraulic switch destroyed
◇Inadequate water-flow
◇Replace the switch
◇Clean the filter and discharge the air
Excessive discharge pressure
◇excessive refrigerant
◇Incondensable gas in the Refrigeration cycle
◇Inadequate water-flow
◇Remove the superfluous refrigerant
◇Drive the gas out
◇Check the circulation and increase the flow
Low suction pressure
◇Drying filter stoppage
◇Lack of refrigerant
◇Excessive pressure drop in the heat exchanger
◇Replace the filter
◇Leak hunting and fill in standard quantity of refrigerant
◇Check the opening of electronic expansion valve

- 20 -
Part VI Wiring Diagram
water refill
magnetic valve
water supply
pump
return water magnetic valve
high water level magnetic switch
low water level magnetic switch
Main Power Supply
compressor
low
pressure
switch
high
pressure
switch
current
detection
current
transformer
transformer
water
tank
temp.
sensor
return
water
temp.
sensor
water
outlet
temp.
sensor
ambient
temp.
sensor
coil
temp.
sensor
electronic
expansion
valve
with commercial control system
GT-SKR030B Wiring Diagram
control
panel
A
FUSE
B
C
N
L N
5 6 8 7 9 10
1 2 3 4
C
R
S
N N N
M
heater
electrical
compressor
four-way
valve
water return
valve
water refill
valve
water
supply
pump
fan-high
speed medium
fan- speed
fan-low
speed
circulating
pump
water
Note:
It is suggested to install extra AC contractor when the power of "circulating pump" and "water refill pump"
are more than 500W respectively, because terminal block only provides control signals, it's prohibited to
connect the power core to "Terminal Block for Control Signal " as it may damage the PCB.
Terminal Block
for Control Signal
PCB
Earth
ON
1 2
SW1
water flow
switch