LAARS NeoTherm NTV (Sizes 150–850 MBTU/h) - Install and Operating Manual - Manual (Page 84)

Page 80 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 the 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 flame is not present in the combustion chamber. Correct
any errors.
2. Make sure that the flame 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
flame 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, flame detector, flame detector
siting or flame 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, flame detector, flame detector
siting or flame rod position.
5. If steps 1 through 4 are correct and the fault persists, replace the
module.
Code Description L or H Procedure