White Rodgers/Robertshaw Gas Valve Testing And Replacement - Bradford White MI30T*F(BN,CX,SX) Service Manual

National Excelsior Company
www.excelsiorhvac.com
The Bradford White
DEFENDER
Safety System
Gas Valve Testing and Replacement (White Rodgers/Robertshaw)
The gas valve is a non repairable device. If trouble shooting has determined a problem with the 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 gas valve may be faulty.
LINE PRESSURE
The 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 (check rating plate). 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 gas valve to "OFF" position.
Step 2. Remove pressure tap plug and install pressure tap.
Step 3. Connect manometer to pressure tap.
Step 4 Follow lighting instructions and proceed to light
main burner and observe manometer reading.
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 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 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.
Testing and Replacement (White Rodgers/Robertshaw)
®
15
Subject to change without notice.
SERVICE PROCEDURE RG-V
Gas Valve
Pressure Tap
Shown Installed
15 15