3
Gas pressure checks are done with
fl
owing gas using a
gas pressure manometer capable of reading pressure in
inches of water column.
Supply gas pressure checks are measured before the gas
control valve and as close to the water heater as possible.
Manifold (main burner) gas pressure is measured at the
pressure tap on the bottom of the gas control valve (see
Figure 1). Use an allen wrench to remove the plug, then
attach the gas gauge.
Note:
Desired gas pressures will be noted on the gas valve
label located on the gas control valve and rating plate.
IF
THEN
Supply gas pressure
is under desired
pressure requirement
I n c r e a s e s u p p l y g a s
pressure regulator setting.
Call the gas utility company
to readjust gas pressure on
main supply. Technicians
can not adjust main gas
supply pressure.
•
•
Supply gas pressure
is over desired
pressure
A d d g a s p r e s s u r e
regulator.
Call the gas utility company
to readjust gas pressure on
main supply. Technicians
can not adjust main gas
supply pressure.
•
•
Manifold gas pressure
is more than +/- .4
inch W.C. from values
indicated on gas valve
or rating plate
Ensure there is adequate
supply gas pressure.
Ensure the main burner
orifice is the correct size
for the water heater model
being tested.
If the above tests have been
performed and the results
were correct replace the
gas control valve.
•
•
•
Important:
After checking the manifold gas pressure,
detach the gas gauge, reinstall the plug using insulation
tape and tighten with allen wrench. Check for leaks and
repair as required.
PRESSURE
MANOMETER
MANIFOLD (MAIN BURNER GAS PRESSURE
TAP). RE-INSTALL PLUG AFTER USE.
Figure 1
CHECKING THE GAS SUPPLY PRESSURE
