The gas valve is designed for a maximum line pressure of 14.0″ W.C., and a minimum line pressure based on the manifold pressure plus 1.0″ W.C. (check rating plate for rated manifold pressure). Line pressure must be checked with burner on and burner off to assure proper readings.
MANIFOLD PRESSURE TESTING
(This procedure presumes a maximum line pressure of 14.0″ W.C.)
Step 1. Set the gas control to the “OFF” position.
Step 2. Remove pressure tap plug (3/16” allen wrench) and install 1/8″ NPT pipe, coupling, and pressure tap.
Step 3. Connect manometer to pressure tap.
Step 4. Follow instructions located on the lighting instructions label and proceed to light the main burner and
observe manometer reading.
Step 5. Proper operating range for natural gas is:
4.0″ ±0.5″ W.C.
Proper operating range for L.P. gas is:
10.0″ ±0.5″ W.C.
a) If pressure is within the range specified in the previous step, set gas control knob to the “OFF” position, remove manometer and pressure tap, and replace pressure tap plug. Check for gas leaks prior to placing water heater back into operation by following the instructions located on the lighting instruction label or the lighting instructions located in the Installation and Operation Manual.
b) If gas pressure is outside the specification noted above, refer to the following Honeywell ONLY information, or “Gas Control Replacement” to replace gas control or valve body.
Step 6. The manifold pressure is NOT adjustable. If manifold pressure is outside of the range in Step 5, the control must be replaced.