Page 66
LAARS Heating Systems
94
Header sensor
fault
H
1. Check wiring and correct any possible errors.
2. Replace the header sensor.
3. If previous steps are correct and fault persists, replace the module.
95
Stack sensor
fault
H
1. Check wiring and correct any possible errors.
2. Replace the stack sensor.
3. If previous steps are correct and fault persists, replace the module.
96
Outdoor sensor
fault
H
1. Check wiring and correct any possible errors.
2. Replace the outdoor sensor.
3. If previous steps are correct and fault persists, replace the module.
97
Internal Fault:
A2D mismatch.
L
Internal Fault.
1. Reset module.
2. If fault repeats, replace module.
98
Internal Fault:
Exceeded
VSNSR voltage
tolerance
L
Internal Fault.
1. Reset module.
2. If fault repeats, replace module.
99
Internal Fault:
Exceeded
28V voltage
tolerance
L
Internal Fault.
1. Reset module.
2. If fault repeats, replace module.
100
Pressure Sensor
Fault
H
1. Verify the Pressure Sensor is a 4-20 ma source.
2. Check wiring and correct any possible errors.
3. Test Pressure Sensor for correct operation.
4. Replace the Pressure sensor.
5. If previous steps are correct and fault persists, replace the module.
105
Flame detected
out of sequence
H or L
1. Check that fl ame is not present in the combustion chamber. Correct
any errors.
2. Make sure that the fl ame detector is wired to the correct terminal.
3. Make sure the F & G wires are protected from stray noise pickup.
4. Reset and sequence the module, if code reappears, replace the fl ame detector.
5. Reset and sequence the module, if code reappears, replace the module.
106
Flame lost in
MFEP
L
1. Check main valve wiring and operation - correct any errors.
2. Check the fuel supply.
3. Check fuel pressure and repeat turndown tests.
4. Check ignition transformer electrode, fl ame detector, fl ame detector
siting or fl ame rod position.
5. If steps 1 through 4 are correct and the fault persists, replace the module.
107
Flame lost early
in run
L
1. Check main valve wiring and operation - correct any errors.
2. Check the fuel supply.
3. Check fuel pressure and repeat turndown tests.
4. Check ignition transformer electrode, fl ame detector, fl ame detector
siting or fl ame rod position.
5. If steps 1 through 4 are correct and the fault persists, replace the module.
108
Flame lost in run
L
1. Check main valve wiring and operation - correct any errors.
2. Check the fuel supply.
3. Check fuel pressure and repeat turndown tests.
4. Check ignition transformer electrode, fl ame detector, fl ame detector
siting or fl ame rod position.
5. If steps 1 through 4 are correct and the fault persists, replace the module.
Summary of Contents for NTV
Page 4: ...LAARS Heating Systems...
Page 11: ...Page 7 NEOTHERM Boilers and Water Heaters...
Page 24: ...Page 20 LAARS Heating Systems Figure 16 Hydronic Piping Single Boiler Zoning with Circulators...
Page 84: ...Page 80 LAARS Heating Systems Parts Illustration 1 Jacket Components...
Page 86: ...Page 82 LAARS Heating Systems Parts Illustration 4 Internal Components Sizes 750 850...
Page 88: ...Page 84 LAARS Heating Systems Parts Illustration 6 Gas Train Components Sizes 600 850...
Page 91: ...Page 87 NEOTHERM Boilers and Water Heaters Notes...
