Gas Pressure Testing - Trane TR250 Service & Installation Manual

GAS PRESSURE TESTING:

The following gas pressure requirements are important to the proper operation of the burners in gas heat-
ers. Improper gas pressure or gas volume will create the following conditions:
1. Flame burns totally yellow.
2. Flame lifts off burner.
3. Heat exchanger soots up. The gas pressure regulator on all heaters is preset at the factory,
but the setting should be verifi ed by the installer to ensure proper operation.
If gas pressure is inadequate, check for undersize piping between the gas meter and the heater or for a
low-capacity gas meter.
GAS PRESSURE TEST PROCEDURE:
Refer to Figure 22 for the location of components used in this procedure on heaters being serviced.
1. Obtain the necessary equipment:
a. Manometer to read pressure in inches of water column
b. 1/8" pipe nipple (1/8" thread x 1" long)
c. 3/16" hex wrench
d. Flat screwdriver
2. Remove the 1/8" plug from the gas valve.
3. Install the 1/8" pipe nipple into the gas valve.
4. Attach the manometer to the pipe nipple.
5. Turn on the water system and start the heater following the lighting & operating instructions on the
label affi xed inside the front access panel. If there is more than one pool/spa heater connected to
the gas supply line, turn each of those appliances "ON" while testing the heater.
Figure 22: Gas Valve
Inlet
pressure
tap plug
ON/OFF
knob
Manifold
pressure
tap plug
Regulator
adjustmernt
screw under
this screw
cap
Adjust regulator pressure by removing
the screw cap and turning the adjustment
screw as shown below.
INCREASE
PRESSURE
Electrical
terminals
DECREASE
PRESSURE
33