STIEBEL ELTRON IS E User manual

1
Service Manual
IS_E / IS_E-2
Author: Mr. Apiwat Limrueangwattanakul
Date: 25 March 2013
Revision: version 1.0

2
Table of Contents
Warning.......................................................................................................................................................... 3
General product information......................................................................................................................... 4
Technical data ................................................................................................................................................ 5
Wiring Diagram .............................................................................................................................................. 6
Troubleshooting............................................................................................................................................. 7
Root clause analysis ....................................................................................................................................... 9
1. Heating Elements checking................................................................................................................ 9
2. TRIAC checking ............................................................................................................................... 10
3. Flow Switch checking ...................................................................................................................... 11
4. PCB Control checking ....................................................................................................................... 13
5. Thermostat checking ...................................................................................................................... 13
6. System comfirm ............................................................................................................................... 15

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 IS pressureless (open) instantaneous water heater is a device for
heating water for shower. The electrical power is electronically controlled. The unit switches the
power on once the flow volume reach 1.5-2 l/min.
The “Power” light (C) indicates that the unit is switched on. If the temperature
adjustment rotary (B) switch is turned to the left, it is possible to take a cold shower (the heating
will not be switched on).
The IS is fitted with an overheating protection device. In the event of overheating the
heating power will be cut off.

5
Technical Data
Model
IS 35E/E-2
IS 45E/E-2
IS 60E/E-2
Type
Opened outlet
Water pressure
0 Mpa (0 bar)
Water connection
G 1/2" (external thread)
Electrical connection

220 V
kW
3.5
4.5
6.0
230 V
kW
3.8
4.9
6.6
240 V
kW
4.2
5.4
7.1
Recommended cable size Sqmm.
4.0
6.0
6.0
Recommended circuit breaker A
20
30
35
Min flow rate to active unit (L/min)
1.3 ± 0.3
2.2 ± 0.3
Thermostat (TCO)
DOUBLE ACTION (55 °C / 75 °C)
Dimension (W x H x D) mm.
350 x 210 x 100

6
Wiring Diagram
Type IS...E / IS…E-2
A = Heating element
B = Electronic control set
C = ELSD Circuit
D= Single Triac Set
E = Thermal cut - out (TCO)
F = Button Board
G = Current Leakage Sensor
Type IS…
A = Heating element
B = Electronic control set
D = Single Triac Set
E = Thermal cut - out (TCO)
A
E
F
D
G

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,
outlet
Power lamp "ON"
but water not hot
- Heating elements failure
- Check Heating
element
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

8
Problem & Condition
Cause
Correction
- Overloaded current on main
breaker
- Power line wrong connection
- Turn off other appliance
- Reconnect power
line
- Water over flow
- Reduce water flow
ELSD 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
v
- 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.
- )))) "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, "∞Multimeter
Pole Tank (P1 - Tank) or (P2 - Tank), (GRD - Tank)
Pole - Pole (P1 - P2), (P1 - GRD) or (P2 - GRD)
IS 60E/E-2
P1
P2
IS 35E/E-2, 45E/E-2
Or
P2
P1
GRD
P2
GRD
P1
Or
Tank
P2
Tank
P1
IS 3E/E-2, 45E/E-2
IS 60E/E-2
GRD
Tank
P1
Tank
Or

10
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
H1
Poles - Ground
L1
GRD
GRD
L1
H1