Bradford-White Corp MI303T, CX), M1XR403S*FCX, MI50L, MI504S Service Procedure RG-V, Line Pressure

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SERVICE PROCEDURE RG-V

Combination Thermostat/Gas Valve Testing

and Replacement

Combination Thermostat/Gas Valve Testing and Replacement

The combination thermostat/gas valve is a non repairable device. If trouble shooting has determined a problem with the combination thermostat/gas valve, it must be replaced.

If the burner and/or pilot do not function, service checks for gas pressure, thermocouple output, magnet assembly and ECO are to be performed. If these check OK, the combination thermostat/gas valve may be faulty.

LINE PRESSURE

The combination thermostat/gas valve is designed for a maximum line pressure of 14.0" w.c. and a minimum line pressure of 1.0"w.c. over the water heater rated manifold pressure. Line pressure must be checked with burner on and burner off to assure proper readings.

MANIFOLD PRESSURE TESTING (this procedure assumes a maximum line pressure of 14.0" w.c.)

Step 1. Set combination thermostat/gas valve to “OFF” position.

Step 2.

Remove pressure tap plug (3/16" Allen wrench) and install

 

 

pressure tap (7/16 wrench)

 

Step 3.

Connect manometer to pressure tap.

 

Step 4

Follow lighting instructions and proceed to light

Pressure Tap

 

main burner and observe manometer reading.

Shown Installed

Step 5

Proper operating range for natural gas is 4.0 ±0.3" W.C.

 

 

Proper operating range for L.P. gas is 10.0 ±0.5" W.C.

 

Step 6

If pressure is OK, set combination thermostat/gas valve to “OFF”

 

remove manometer and pressure tap and replace pressure tap plug. Check for gas leaks before placing water

 

heater back in operation. If pressure is out of the specification noted in step 5, proceed to step 7 or 8 for proper

 

service procedure.

 

Step 7

For White Rodgers control, the manifold pressure is not adjustable. If manifold pressure is outside the range

 

in step 5, the control must be replaced.

 

Step 8

For Robertshaw control, the manifold pressure is adjustable, proceed to step 9 for adjustment procedure

Step 9

While burner is in operation, remove regulator access cap to expose the regulator adjusting screw. With small

 

screw driver, rotate adjusting screw clockwise to increase pressure and counter clockwise to decrease pressure.

Step 10 Replace regulator access cap, set combination thermostat/gas valve to “OFF”. Remove manometer and pressure tap and replace pressure tap plug. Check for gas leaks before placing water heater back in operation.

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Contents MI30T*FBN,CX M430T*FBN,CX MI50L*FBN,CX M1XR403S*FBN,CX MI504S*FBN,CX M1XR504T*FBN,CXMI60T*FBN,CX M2XR504T*FBN,CX M2C504T*FBN,CX 50T65FBN,CX Table of Contents Bradford White Defender Safety System IntroductionTroubleshooting Chart Flammable Vapor Ignition Resistant Water HeatersService Procedure RG-I Proceed to Inner Door Gasket Replacement ProcedureFollowed exactly, a fire or explosion may result causing If the information in these instructions is notInstallation of Inner Door With Gasket Replace outer jacket burner access door Service Procedure RG-II Thermocouple Testing and ReplacementClosed Circuit Thermocouple Testing White Rodgers Control Closed Circuit Thermocouple Testing Robertshaw ControlOpen Circuit Thermocouple Testing Thermocouple ReplacementService Procedure RG-III Pilot Assembly Inspection, Cleaning and ReplacementService Procedure RG-IV Piezo Igniter, Electrode Testing and ReplacementPiezo IGNITER, Electrode Testing and Replacement Service Procedure RG-V Combination Thermostat/Gas Valve Testing ReplacementCombination Thermostat/Gas Valve Testing and Replacement Line PressureThermocouple Testing Magnet Assembly Testing White Rodgers ControlMagnet Assembly Testing Robertshaw Control ECO Energy Cut Off Testing Combination THERMOSTAT/GAS Valve ReplacementWrench Boss Explosion causing property damage Seal breach may result in a fire orPersonal injury or death Service Procedure RG-VI Main Burner Inspection, Adjustment Cleaning and ReplacementCast Iron Burner Adjustment Feedline Burner Cleaning Service Procedure RG-VII Resetting Thermal Switch Testing and ReplacementResettable Thermal Switch Continuity Testing Resettable Thermal Switch Replacement Over Tighten ScrewsService Procedure RG-VIII ScreenLok Flame Arrestor CleaningScreenLok Flame Arrestor Cleaning Service Procedure RG-IX Dip Tube and Anode Inspection and ReplacementDIP Tube Inspection and Replacement Anode Inspection and Replacement Parts List Page Page Fax/215-641-1612
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