58
LP- 276 REV. 9.4.14
C. BOILER FAULT
1. When a fault condition occurs, the controller will illuminate the red “fault” indication light and display a fault code. The alarm output
will also be activated. Most fault conditions will also cause the CH pump to run in an attempt to cool the boiler.
2. Note the fault code and refer to Table 20 for an explanation of the fault code along with several suggestions for corrective actions.
3. Press the reset key to clear the fault and resume operation. Be sure to observe the operation of the unit for a period of time to assure
correct operation and no recurrence of fault codes.
When servicing or replacing any components of this boiler, be certain that:
•
The gas is off.
•
All electrical power is disconnected.
When servicing or replacing components that are in direct contact with the boiler water, be certain that:
•
There is no pressure in the boiler. (Pull the release on the relief valve. Do not rely on the pressure gauge reading.
•
The boiler water is not hot.
•
The electrical power is off.
DO NOT USE THIS APPLIANCE IF ANY PART HAS BEEN SUBMERGED IN WATER.
Immediately call a qualified service technician.
The appliance MUST BE replaced if it has been submerged. Attempting to operate an appliance that has been submerged could create
numerous harmful conditions, such as a potential gas leakage causing a fire and/or explosion, or the release of mold, bacteria, or other
harmful particulates into the air. Operating a previously submerged appliance could result in property damage, severe personal injury,
or death.
NOTE:
Appliance damage due to flood or submersion is considered an Act of God, and IS NOT covered under product warranty.
This appliance has wire function labels on all internal wiring. Observe the position of each wire before removing it. Wiring errors may
cause improper and dangerous operation. Verify operation after servicing.
If overheating occurs, or the gas supply fails to shut off, do not turn off electrical power to the circulating pump. This may aggravate the
problem and increase the likelihood of boiler damage. Instead, shut off the gas supply to the boiler at the gas service valve.
926 CONTROL BOARD ERROR CODES
CODE
DESCRIPTION
CORRECTIVE ACTION
E19
Line voltage
frequency out of
range.
Inspect power wiring to appliance and repair as necessary. If connected to line voltage, notify power company. If
connected to an alternate power source, such as a generator or inverter, make sure line voltage frequency supplied by the
device is 60 Hz. No reset is necessary, as this blocking code clears automatically after the problem has been corrected.
FLU
Blocked Vent
Pressure Switch
1. Check the flue vent to be sure it is not blocked or damaged.
2. Check the switch wiring by applying a jumper in place of the switch. If the code clears with the jumper in place,
REPLACE the flue switch and connect the wires to the new switch BEFORE running the boiler.
WARNING: Do not use jumper to remedy this error. Faulty switches MUST be replaced. Failure to do so could result in
serious injury or death.
LEO
Water Level in
Boiler is Low
1. Check boiler feed water system to be sure it is supplying make-up water to the boiler system.
2. Be sure all air is bled from system.
3. Check for leaks in boiler and system piping and repair as necessary.
4. Inspect low level switch and wiring for damage and repair if necessary.
LOU
24 Volt Low
1. Check line voltage. Must be between 100 – 128 volts.
2. If available, connect a PC and, using HTP service software, check the 24v supply display in the lower left corner of the
screen. The number displayed here must be greater than 128 and should be greater than 250. Use this as a
troubleshooting guide as you follow the steps below.
3. Remove 10 pin Molex connector from customer connection board. If LOU clears, then the problem is with external
sensor wiring. Examine external sensor wiring for shorts to ground, repairing as necessary. If LOU code is still present and
the heater is so equipped, disconnect high gas pressure switch, then low gas pressure switch, then UL 353 low water
cutoff in this order, one at a time, to see if LOU code clears. Replace faulty part. Check low voltage wire harness in heater
for shorts to ground.
4. If LOU only occurs when burner tries to light, check gas valve for excessive current draw.
5. If LOU is present with the low voltage harness disconnected from the 926 control board, replace the 926 control board.
Summary of Contents for Mod Con 300 VWH
Page 12: ...12 LP 276 REV 9 4 14 Figure 2 Dimensions and Specifications ...
Page 22: ...22 LP 276 REV 9 4 14 I PIPING DIAGRAMS Figure 6 ...
Page 49: ...49 LP 276 REV 9 4 14 Figure 28 Mod Con Internal Connection Diagram LP 255 ...
Page 63: ...63 LP 276 REV 9 4 14 Figure 31 ...
Page 64: ...64 LP 276 REV 9 4 14 Figure 32 ...
Page 65: ...65 LP 276 REV 9 4 14 Figure 33 NOTE Ceramic Refractory Part 7250P 162 ...
Page 66: ...66 LP 276 REV 9 4 14 Figure 34 ...
Page 67: ...67 LP 276 REV 9 4 14 Figure 35 ...
Page 70: ...70 LP 276 REV 9 4 14 ...
Page 71: ...71 LP 276 REV 9 4 14 ...
