Trouble Shooting Chart - Bradford White MI30T*F(BN,CX,SX) Service Manual

National Excelsior Company
www.excelsiorhvac.com
White Rodgers/Robertshaw Gas Valve Troubleshooting Chart
SYMPTOM
1. No incoming gas or too low gas
2. Gas control knob set to wrong position.
3. Pilot light button not being fully
Pilot Will Not Light
4. Pilot orifice or pilot tube is obstructed or
5. Pilot electrode not sparking to pilot.
6. Piezo igniter not functioning.
1. Poor thermocouple connection at
2. Thermocouple not fully engaged in pilot
Pilot Will Not
3. Pilot flame is not fully enveloping the
stay lit
when button is
4. Weak or defective thermocouple.
5. Open ECO on combination thermostat/
released
6. Defective magnet in combination
7 Resettable thermal switch has opened.
1. Combination thermostat/gas valve set too
Pilot will light but
2. Combination thermostat/gas valve
the main burner
3. Insufficient gas supply or low gas
will not come on
4. Combination thermostat/gas valve has
Pilot goes out
1. Insufficient combustion air supply.
periodically (after
2. Incorrect, clogged vent system/ vent
heating cycles,
once a day, once
3. Inconsistent gas supply or gas pressure.
a week etc.)
1. Combination thermostat/gas valve set too
2. Cold inlet water temperature is very cold.
3. High demand periods.
Not enough hot
4. Incorrectly sized water heater for
water
5. Combination thermostat/gas valve is out
6. Out of spec dip tube is diluting hot water
4 4
Flammable Vapor Ignition Resistant Water Heaters
PROBABLE CAUSE
pressure.
depressed when attempting to light pilot.
kinked.
combination thermostat/gas valve.
assembly bracket.
thermocouple "hot" junction.
gas valve.
thermostat/gas valve.
low for desired water temperature.
temperature is satisfied.
pressure.
wide differential or is out of calibration.
terminal or location.
low for desired water temperature.
application.
of calibration/not functioning.
with cold water.
Subject to change without notice.
CORRECTIVE ACTION
1. Turn on gas supply and/or check line
pressure.
2. Review lighting instruction. Set
combination/thermostat
gas valve to correct position.
3. Review lighting instruction. Fully depress
pilot lighting button.
4. Clean, repair or replace.
5. Verify correct electrode position. Replace
pilot assembly.
6. Replace Piezo igniter.
1. Check connection at combination
thermostat/gas valve. Proper tightness
should be finger tight plus ¼ turn.
2. Inspect thermocouple to ensure that it is
fully engaged into pilot bracket.
3. Adjust tip of thermocouple to be fully
engulfed by pilot flame.
4. Check thermocouple and replace if
necessary.
5. Check ECO continuity and replace
combination thermostat/gas valve if
necessary.
6. Check magnet operation and replace
combination thermostat/gas valve if
necessary.
7. Determine cause of switch activation. To
reset, depress button on resettable thermal
switch located on inner door.
1. Adjust temperature dial on combination
thermostat/gas valve.
2. Check temperature dial setting on
combination thermostat/gas valve.
3. Check gas supply and line pressure.
4. Check combination thermostat/gas valve
for proper operation, replace if
necessary.
1. Verify adequate combustion air is available
to the unit. Check and clear Jacket slot
openings of any dirt, dust, restrictions or
other obstructions. Inspect flame arrestor
plate and clean with stiff bristled brush
and/or vacuum to remove any debris
accumulation.
2. Check venting for proper sizing and proper
operation
3. Check gas supply and line pressure.
1. Check dial on combination thermostat/gas
valve.
2.Extremely cold water going into the heater
will decrease the amount of hot water
produced. It may be necessary to temper
incoming water supply.
3. Adjust high demand usage.
4. Contact Plumbing professional.
5. Check combination thermostat/gas valve
for proper operation, replace if
necessary.
6. Inspect dip tube and replace if necessary.
4
SERVICE
PROCEDURE
1. See Service Procedure
RG-V, Page 12.
4. See Service Procedure
RG-III, Page 10.
5. See Service Procedure
RG-III, Page 10.
6. See Service Procedure
RG-IV, Page 11.
4. See Service Procedure
RG-II, Page 8
5. See Service Procedure
RG-V, Page 14
6. See Service Procedure
RG-V, Page 13
2. See Installation &
operation manual.
3. See Service Procedure
RG-V, Page 12
4. See Service Procedure
RG-V, Page 12
1. See Service Procedure
RG-VIII, Page 22
3. See Service Procedure
RG-V, Page 12
5. See Service Procedure
RG-V, Page 12
6. See Service Procedure
RG-IX, Page 23