STIEBEL ELTRON IM 45 EC User manual

1
Service Manual
IM_EC
Author: Mr. Apiwat Limrueangwattanakul
Date: MAY 2015
Revision: version 0

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Table of Contents
Warning.......................................................................................................................................................... 3
General product information......................................................................................................................... 4
Technical data ................................................................................................................................................ 5
Wiring Diagram ...............................................................................................................................................
Troubleshooting..............................................................................................................................................
Root clause analysis ........................................................................................................................................
1. Heating Elements checking.................................................................................................................
2. TRIAC checking.................................................................................................................................. 
3. Flow Switch checking ........................................................................................................................ 
4. Control PCB checking ........................................................................................................................ 
5. Thermostat checking......................................................................................................................... 
6. ELCB checking.................................................................................................................................... 
7. ELCB function testing ........................................................................................................................ 
8. System comfirm ................................................................................................................................ 

3
Warning
Warning: This service manual is suitable for qualified Technicians only.
Warning: Disconnect power supply before open cover.

4
General product information
The STIEBEL ELTRON IM flow-controlled, pressurized instantaneous water heater heats the water
while it is flowing through the unit. The heating power is switched on automatically in the event of the


5
Technical data
Model
IM 45EC
IM 60EC
IM 80EC
Type
Closed outlet
Min. inlet water pressure MPa(bar)
0.015(0.15)
0.02(0.2)
0.03(0.3)
Max. inlet water pressure MPa(bar)
1(10)
Water connection
G 1/2"
Electrical connection

220 V
kW
4.5
6.0
8.0
230 V
kW
4.9
6.6
8.7
240 V
kW
5.4
7.1
9.5
Recommended cable size Sqmm.
2.5 - 4.0
4 6
6 8
Recommended circuit breaker A
25
32
40
Dimension (W x H x D) mm.
186 x 164 x 76

6
Wiring Diagram
Type DX…E
A = Heating element
B = Electronic control set (Phase Cut)
C = ELCB
D= Triac Set
E = Thermal cut - out (TCO)
E
B
A
D
C

7
Troubles shooting
- ELSD cut-off
- Check filter, and flow
rate
-Low flow
- No power supply to unit
- Power line not tight
- Check breaker
- Thermal cut-out (TCO)
- Check Triac set
- Check Reed switch
- Cleaning magnet
- Check PCB
- ELSD reset
- Check connecting
points and fix.
Power lamp not "ON"
and water not hot
- PCB failure
- Check PCB
- Missing water connection
- Check reed switch
- Reed switch failure
- Check Triac set
- Triac failure
Problem & Condition
Cause
Correction
- Reconnect inlet,
Power lamp "ON"
but water not hot
- Heating elements failure
- Check Heating
Power lamp not "ON"
but water Hot
- Lamp broken
- Lamp cable broken
- Check & change the Lamp
- Check & change Lamp
cable
Power lamp "ON" all the
time
- Reed switch failure
- Check reed switch
- Triac short circuit
- Check Triac set

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Problem & Condition
Cause
Correction
- Overloaded current on main
breaker
- Power line wrong connection
- Turn off other appliance
- Reconnect power
- Water over flow
- Reduce water flow
Breaker cut-off
- Reed switch failure
Water temperature
not constant
- Change pump to
smooth pressure type
- Check reed switch
- Irregular water flow
- Triac failure
- Check Triac set
Water leak
- Wrong installation
- Reinstallation
- Connector has loosen
- Tight connectors
- PCB failure
- Check PCB
Power on maximum but
water not hot enough
Water too hot
Troubles shooting

9
Root clause analysis
1. Heating Elements Checking
Definition: Heating Element is a metal coil that heats up to high temperatures, when
electricity is applied. To check the Heating Element, follow the steps below:
- Disconnect cables from the Elements.
- Set Mu)))) "and check as show in the pictures.
Check
Meter Result
Cause
Action
Pole Pole
"Beep" signal or (~ 0 )
Element Pass
No action
No signal "OL" or (
Element Broken
Change New Heater
Pole GRD
"Beep" signal or (~ 0 )
Element short to tank
Change New Heater
No signal "OL" or (
Element Pass
No action
Remark: "OL" = Over Load for Digital Multimeter, "alog Multimeter
Pole - Tank (P1 - Tank), (P2 Tank) and (P3 Tank)
Tank
P2
P3
Tank
Tank
P1
Pole Pole (P1 - P2), (P1 P3) and (P2 P3)
P2
P1
P3
P2
P3
P1

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2. TRIAC Checking
Definition: The Triac is a three-terminal device, which controls and conducts current flow during
both alternations of an AC cycle. To check Single Triac, follow the steps below:
- Disconnect cables and unplug any connectors in red circle.
- )))) " and check as show in the pictures.
Note; L1 = line, H1 = Heater, GRD = Ground
Check
Meter Result
Cause
Action
L1 H1
"Beep" signal or (~ 0 )
Triac short circuit
Change new
No signal "OL" or (
Triac Pass
No action
Check
Meter Result
Cause
Action
L1 - GRD
"Beep" signal or (~ 0 )
Triac short circuit
Change New Triac PCB
No signal "OL" or (
Triac Pass
No action
H1- GRD
"Beep" signal or (~ 0 )
Triac short circuit
Change New Triac PCB
No signal "OL" or (
Triac Pass
No action
Remark: "OL" = Over Load for Digital multimeter, "ultimeter.
GRD
L1
H1
H1 - GRD
H1
GRD
Pole Ground
(L1 GRD) &
(H1 GRD)
L1 - GRD
L1
GRD

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3. Flow Switch Checking
- )))) " and unplug reed switch from PCB then check it as
show in the pictures.
Check
Meter Result
Cause
Action
Pole - Pole
No signal "OL" or (
Reed SW contact closed
Change Reed SW 
"Beep" signal or (~ 0 )
Pass
No action
*Note: Recommend replacing magnet set at the same time.
Pole - Pole

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4. PCB control Checking
Visual check
Check
Result
Cause
Action
Visual
Electronic equipment burn
PCB short circuit
Change new one
No visible damage
PCB failure
Change new one

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5. Thermostat resetting
Manual Reset Thermostat
Definition: 
 check the thermostat, follow the steps below:
-Disconnect cables as in the picture.
- ))))
- Check on poles.
Check
Meter Result
Cause
Action
Pole -Pole
"Beep" signal " )))) "
Pass
No action
No signal "OL" or (∞
Connector open
Reset manual button*
Remark: "OL" = Over Load for Digital multimeter, "ultimeter.
*Note: Please ensure that step 1-

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6. ELCB checking
Function: ELCB will cut out the Electric power system, when leakage is approximately 15 mA.
- Disconnect Electric power lines as in the pictures.
- )))) " and check as shown in the pictures.
- Note the differences in the locations of the multimeter pointers .
Check
Meter Result
Cause
Action
ON
"Beep" signal " )))) "
Pass
No action
No signal "OL" or (∞
ELCB damaged
Change new ELCB
OFF
"Beep" signal " )))) "
ELCB damaged
Change new ELCB
No signal "OL" or (∞
Pass
No action
ON Position
OFF Position

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7. ELCB function testing
- Connect electric power lines as in the pictures.
- Supply electricity.
- ELCB will cut out the power when the ELCB test button is pressed.
ELCB Test = Pressleft rod ELCB Reset =Pressright rod
(ELCB ) (ELCB )
Check
Result
Cause
Action
ELCB Test
ELCB cut out power
Pass
No action
ELCB not cut out power
ELCB failed
Change new ELCB
ELCB Reset
ELCB connect power
Pass
No action
ELCB not connect power
ELCB failed
Change new ELCB

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8. System confirm
Ensure that you have tightened all the screws back into their original positions. This final test must
be performed after repairing the unit. If all steps below are working correctly the unit can be
returned to the end user.
1. If available, set the unit in test station and turn the knob to the OFF position.
2. Connect electricity wiring to the unit and connect the water valve, then supply water to
the system to check for leaks but keep the main breaker to the unit turned off.
3. If no water leaks where discovered turn the breaker on and push the reset button
upwards to reset the ELCB.
4. Try to adjust knob (temperature). If the water is warm, the unit is ready to use.
5. Purge water inside tank and the unit is cleaned with compressed air.