9 - troubleshooting – Dunkirk Q95M-200 Modulating Condensing Boiler User Manual
Page 20

20
HARD LOCKOUT (Display flashes first digit “E” and last two digits (code))
Code
Reason For Hard Lockout
Corrective Actions (pressing RESET should restart boiler immediately):
WARNING: Electrical shock hazard. Turn off power to boiler when working with wiring or replacing any boiler component.
09
Internal control failure.
1
Reset control and retry. If problem persists, replace control module.
11
12
Casting temperature switch opened.
1
Determine reason for limit action and correct. Check for air trapped at top of
casting.
2
If limits are closed, check wiring and connections. Apply a temporary jumper
across terminals 6 and 8 and check operation. If problem persists, check boiler
internal wiring. Replace low voltage harness if necessary. Replace control
module if harness replacement doesn’t resolve.
13 -
17
Internal control failure.
1
Reset control and retry. If problem persists, replace control module.
18
Thermal Overrun Condition:
Outlet water temp. above 200 °F
1
Check system for:
Verify boiler and system are full of water.
Make sure system does not have trapped air.
Inspect and verify system piping and components.
Make sure water flow is not reversed or pipes crossed.
2
Use contact thermometer to check outlet water temp. Compare to temp.
shown with display in “INFO” mode (“1” in first digit). Replace return temp.
sensor if results are not close. Replace control module if sensor replacement
doesn’t solve problem.
19
Thermal Overrun Condition:
Return water temp. above 190 °F
1
See Code 18, Corrective Action#1 (above).
2
Use contact thermometer to check return water temp. Compare to temp.
shown with display in “INFO” mode (“2” in first digit). Replace return temp.
sensor if results are not close. Replace control module if sensor replacement
doesn’t solve problem.
28
Blower not running.
1
Turn off power to boiler. Remove line voltage connector at blower. Restart
boiler and check voltage across blower plug terminals. If 120 vac is NOT
present, inspect wiring and tightness of connections. Replace line voltage
wire harness if necessary. Replace control module if wire harness replacement
doesn’t resolve.
2
If 120 vac is present on blower wire harness, replace harness and retry. If
problem persists, replace blower motor.
29
Blower signal not 0 when it should
be.
1
Inspect wiring and connections. If wiring is correct, replace blower assembly. If
blower assembly replacement is unsuccessful, replace control module.
30
Temp difference between supply
& return, indicated by blocking
code b30, was too large for 20
successive times. Non adjustable
default Max Delta set to 100°F
1
Inspect supply & return water sensors for proper resistance.
2
Inspect piping for proper configuration. For example, when used in a radiant
heating application.
31
Outlet water temp. short circuit.
1
Inspect outlet water temp. sensor and wiring. Replace sensor if wiring correct
and in good condition. Replace low voltage wiring harness if problem persists.
Replace control module if harness replacement doesn’t resolve.
32
Return water temp. short circuit.
1
Inspect return water temp. sensor and wiring. Replace sensor if wiring correct
and in good condition. Replace low voltage wiring harness if problem persists.
Replace control module if harness replacement doesn’t resolve.
36
Supply water temp. sensor open
circuit.
1
See Corrective Action# 1 under Code 31 (above)
37
Return water temp. sensor open
circuit.
1
See Corrective Action# 1 under Code 32 (above)
44
Internal control failure.
1
Rest control and retry. If problem persists, replace control module.
60
61
65
Blower signal too low (not enough
driving force).
1
Inspect wiring and connections. If wiring is correct, replace blower assembly. If
blower assembly replacement is unsuccessful, replace control module.
9 - TROUBLESHOOTING