78
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MN-35949
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Rev 07
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01/20
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Combitherm® CT PROformance™ and CT Classic™ Series Technical Service Manual
Troubleshooting
Classic, Electric, Boiler-Free: No Steam Production — Steam at 212°F (100°C)
Is the convection fan motor spinning?
No
See “Convection Motor Is Not Spinning”.
Yes
Is the Steam Bypass Probe B5 below the set point?
No
The appliance will not call for steam production until the
B5 probe is below the set point. If the B5 probe is reading
incorrectly, test the probe and replace the probe if necessary
Yes
Is the Convection Element Contactor K41 closed?
No
Check for voltage across the coil of K41. If voltage is present,
replace the faulty contactor. If voltage is not present,
determine which leg is missing and correct:
• A1 is L1 and it is supplied to the K41 contactor from the
Control Board (CB) terminal X02 pin 1.
• A2 is L2 and it is supplied to the K41 convection element
contactor from the Cavity High Limit Reset N7 terminal 11.
Reset the High Limit if it is tripped.
Yes
Is there line voltage being supplied to terminals 2-4-6 on the
K41/K44 contactors?
No
Repair the wiring issue between the main terminal blocks 1-1,
6-1, 11-1 and the K41 contactors.
Yes
Is there line voltage across terminals 1-3-5 on the K41
contactor?
No
Replace the faulty contactor(s).
Yes
Is there voltage across element loops at the convection
elements?
No
Repair the wiring between the contactors and the elements.
Yes
Are all element loops drawing current?
No
Replace the faulty element assembly.
Yes
Is the Steam Injection Solenoid Y1 being energized?
No
Determine which line is missing at the solenoid.
• A1 is L1 supplied from CB terminal X04 pin 3
• A2 is L2 supplied from Y3/A2 which is supplied from
terminal block 27-17
Yes
Is the Y1 solenoid valve opening?
No
Replace the faulty solenoid.
Yes
Is water going through the steam water flow control?
No
Inspect, clean, or replace the steam water flow control as
necessary.
Yes
Is water being injected into the fan wheel inside the
appliance?
No
Correct the obstruction between the flow control valve and
the injection tube.
Yes
The appliance should begin producing steam in 5 minutes.