Triac Checking - STIEBEL ELTRON AQ 35 E-2 Service Manual

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.
- Set Multimeter to Ohm range "Ω" or "
Check
L1 – H1
GRD
Check
"Beep" signal or (~ 0 Ω)
L1 - GRD
No signal "OL" or ( Ω)
"Beep" signal or (~ 0 Ω)
H1- GRD
No signal "OL" or ( Ω)
Remark: "OL" = Over Load for Digital Multimeter, " Ω" = Over Load for Analog Multimeter

2. TRIAC Checking

) " and check as show in the pictures.
)
)
)
Note; L1 = line, H1 = Heater, GRD = Ground
Meter Result
"Beep" signal or (~ 0 Ω)
No signal "OL" or ( Ω)
Poles - Ground
L1
Meter Result
Cause
Triac short circuit
Triac Pass
Cause
Triac short circuit
Triac Pass
Triac short circuit
Triac Pass
9
H1
L1
GRD
Action
Change new
No action
GRD
H1
Action
Change New
Triac PCB
No action
Change New
Triac PCB
No action