Error Codes
Note
When an error occurs be sure to determine the code before resetting it. If you forget which error code
occurred, see the Errors screen to view the last 200 errors, with date, time, and description.
Error
Location
Type
Description
Cause
Solution
Short circuit in
heater wiring.
Check wiring for touching
wires.
A4DA
Heater A
High Current A
Bad Heater.
Confirm resistance of
heater. Heater resistance
should be 18–21 Ω for
each heater element, 9–12
Ω combined for 10 kW
systems, 6-8 Ω for 15 kW
systems, and 4–6 Ω for
20 kW systems. If out of
tolerance, replace heater
element.
Short circuit in
heater wiring.
Check wiring for touching
wires.
A4DB
Heater B
High Current B
Bad Heater.
Confirm resistance of
heater. Heater resistance
should be 18–21 Ω for
each heater element, 9–12
Ω combined for 10 kW
systems, 6-8 Ω for 15 kW
systems, and 4–6 Ω for
20 kW systems. If out of
tolerance, replace heater
element.
Check continuity of
transformer windings.
Normal readings are about
0.2Ω on both primary and
secondary. If reading is 0Ω
replace transformer.
A4DH
Hose
High Current Hose
Short circuit in
hose wiring.
Check for shorts between
the primary winding and the
support frame or enclosure.
A7DA
Heater A
Unexpected Current
A
Shorted TCM
If error cannot be cleared
or regenerates consistently,
replace module.
A7DB
Heater B
Unexpected Current
B
Shorted TCM
If error cannot be cleared
or regenerates consistently,
replace module.
A7DH
Hose
Unexpected Current
Hose
Shorted TCM
If error cannot be cleared
or regenerates consistently,
replace module.
18
334946A
