RG150T6N – White Rodgers Mechanical Gas Control Troubleshooting Chart


Symptom Probable Cause Corrective Action  Service  


Pilot will not light 1.No incoming gas or too low gas pressure. 

2.Gas control knob set to 

wrong position. 

3.Gas control knob not being fully depressed when 

attempting to light pilot. 

4.Pilot orifice or pilot tube is obstructed or kinked. 

5.Pilot electrode not sparking to pilot. 

6.Piezo igniter not functioning.

1.Turn on gas supply and/or check line pressure. 

2.Review lighting instruction. Set gas  control knob to correct position. 3.Review lighting instruction. Fully depress gas control knob. 

4.Clean, repair or replace. 

5.Verify correct electrode position. Replace pilot assembly. 

6.Replace piezo igniter.

1.See Service 

Procedure RG-V 

2.See Service 

Procedure RG-III 

3.See Service 

Procedure RG-III 

4.See Service 

Procedure RG-IV

Pilot will not stay lit  when button is  released 1.Poor thermocouple 

connection at combination 

thermostat/gas valve. 

2.Thermocouple not fully 

engaged in pilot assembly 


3.Pilot flame is not fully 

enveloping the thermocouple bulb. 

4.Weak or defective 


5.Open ECO in 

combination thermostat/ 

gas valve. 

6.Defective magnet in 

combination thermostat/gas valve. 

7.Resettable thermal switch has opened.

1.Check connection at combination  thermostat/gas valve. Proper  tightness should be finger tight  + a 1/4 turn. 

2.Inspect thermocouple to ensure  that it is fully engaged into pilot  bracket. 

3.Clean pilot orifice and verify pilot  tube is clear; check gas supply  and line pressure. 

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.See Service  

Procedure RG-II 

2.See Service  

Procedure RG-V 

3.See Service  

Procedure RG-V

Pilot will light but the main burner will not come on 1.Combination thermostat/gas valve set too low for desired water temperature. 


thermostat/gas valve 

temperature is satisfied. 

3.Insufficient gas supply or low gas pressure. 

4.Combination thermostat/gas valve has wide differential or is out of calibration.

1.Adjust temperature dial on  

combination thermostat/gas  


2.Check temperature dial  

setting on combination  

thermostat/gas valve. 

3.Check gas supply and line  


4.Check combination  

thermostat/gas valve for  

proper operation, replace if  


1.See Installation  and Operation  


2.See Service  

Procedure RG-V 

3.See Service  

Procedure RG-V


Symptom Probable Cause Corrective Action  Service  


Pilot goes out  periodically (after  heating cycles,  once a day, once  a week etc.) 1. Insufficient combustion air  supply. 

2. Incorrect or clogged vent  system/vent terminal, or 

incorrect location. 

3. Inconsistent gas supply or  gas pressure.

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 compressed  air to remove any debris 


2. Check venting for proper sizing and proper operation. 

3. Check gas supply and line pressure.

1. See Service  

Procedure RG 


2. See Service  

Procedure RG-V

Not enough hot water 1. Combination thermostat/gas  valve set too low for desired  water temperature. 

2. Cold inlet water temperature  is very cold. 

3. High demand periods. 

4. Incorrectly sized water 

heater for application. 

5. Combination thermostat/gas  valve is out of calibration/not  functioning. 

6. Out of spec dip tube is  diluting hot water with cold  water.

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.

1. See Service  

Procedure RG-V 

2. See Service  

Procedure RG-IX