LAARS Heating Systems
Page 90
50
Modulation fault
H
Internal sub-system fault.
1. Review alert messages for possible trends.
2. Correct possible problems.
51
Pump fault
H
52
Motor tachometer fault
H
53
AC input phases reversed
L
1. Check the module and display connections.
2. Check the module power supply and make
sure that both frequency and voltage meet the
specifications.
3. On 24 VAC applications, assure that J4 terminal
10 and J8 terminal 2 are connected together.
59
Internal Fault: Mux pin shorted
L
Internal Fault.
1. Reset module.
2. If fault repeats, replace module.
61
Anti short cycle
H
Will not be a lockout fault. Hold Only.
62
Fan speed not proved
H
63
Rollout switch, is regarding the
SAFETY DEVICES
(OFF)
To diagnose, test all of the following:
Flow Switch
Additional High Limit (Field Supplied)
Low Water Cut Off
Low pressure gas switch – Inlet Side of
Gas Valve
High Pressure gas switch – Outlet Side
of Gas Valve
Condensate Level Switch
H
1. Reset the low gas pressure valve and the high
gas pressure valve.
2. Check for power at all Safety Components.
3. Check wiring and correct any faults.
4. Check all safety interlocks connected to the
safety circuit to assure proper function.
5. If code persists, contact Tech Support.
64
PII (Pre-Ignition Interlock) OFF
H or L 1. Check wiring and correct any faults.
2. Check Preignition Interlock switches to assure
proper functioning.
3. Check the valve operation.
4. Reset and sequence the module; monitor the
PII status.
5. If code persists, replace the module.
67
ILK (Interlock) OFF
H or L 1. Check wiring and correct any possible shorts.
2. Check Interlock (ILK) switches to assure proper
function.
3. Verify voltage through the interlock string to the
interlock input with a voltmeter.
4. If steps 1-3 are correct and the fault persists,
replace the module.
68
ILK (Interlock) ON
H or L
70
Wait for leakage test completion
H
1. Internal Fault. Reset module.
2. If fault repeats, replace module.
78
Demand Lost in Run
H
1. Check wiring and correct any possible errors.
2. If previous steps are correct and fault persists,
replace the module.
