Lochinvar F0600187510 service manual Gas Manifold Pressure Adjustment

Commercial Pool Heaters

INSTALLATION Continued

Gas Manifold Pressure Adjustment

IMPORTANT: The gas valves are referenced to the fan pressurized chamber by a hose connected from the vent of the gas valve regulator to the chamber pressure tap located on the front inside portion of the jacket. Reference the drawings in this section for component and connection points for pressure measurement. The procedure for connecting a manometer or magnahelic must be followed to obtain actual net manifold pressure for normal operation. A manometer or magnahelic gauge legible in 0.1" increments up to 10 inches w.c. is required to check and adjust the manifold pressure. The regulator cover screw on the gas valve must be in place and tight at all times for the pool heater to operate properly.

1.Remove the thumbscrew that fastens the control panel access door and pull out the control panel.

2.Turn the power switch located in the lower left corner behind the control panel access door to the “O” or “OFF” position.

3.Remove the top front jacket access panels to access the gas valves.

4.Locate the reference hose on the second gas valve which goes from the vent fitting on the gas valve to a barbed fitting on the deck of the pool heater (see Figure 31).

5.Remove the flexible cap from the barbed fitting on the “tee” located in this line and hook one side of the manometer, or (-) side of a magnahelic gauge, to this “tee”. Retain this cap for future use.

6.Remove the 1/8" hex plug from the manifold pressure tap on the gas valve (see Figure 31). Retain plug for future use.

7.Install a fitting in this tap that is suitable for connection of a hose to a manometer, or (+) side of a magnahelic gauge (see Figure 31).

8.Turn the power switch to the “I” or “ON” position.

9.Push the reset button(s) for the ignition control(s), if necessary.

10.Set the temperature control to call for heat (see Programming Temperature Control, page 41).

11.Once the pool heater is firing the manometer/magnahelic will reflect the Manifold Gas Pressure. Compare this reading to the respective value in TABLE-L, page 31 for Natural or Propane Gas.

12.If adjustment is necessary, remove the regulator cover screw on the gas valve.

Note: If the gas valve under adjustment is located on a manifold assembly monitored by an igniter, the pool heater may shut down and recycle when the regulator cover screw is removed. This is normal.

13.	Turn the regulator adjustment screw “clockwise” ; to raise the
	regulator gas pressure. Turn the regulator adjustment screw
	“counterclockwise”; to lower the regulator gas pressure.
14.	Replace the regulator cover screw and make sure it is tight for
	proper operation.
15.	Read the value on the manometer/magnahelic and compare it
	to the values in TABLE-L.
16.	Repeat this adjustment procedure for each gas valve as necessary
	to adjust to the proper manifold gas pressure.

MANIFOLD

PRESSURE

4
3
2
1
0
1	CHAMBER
2	PRESSURE

3

4

MANOMETER

CAP
INLET	PRESSURE
	REGULATOR
	ADJUSTMENT
	(UNDER CAP SCREW)
BARBED
FITTING
GAS
VALVE
CONTROL
KNOB
	1/8" HEX
	MANIFOLD
OUTLET	PRESSURE
	TAP

17.	Remove hoses, replace and tighten plugs and caps when
	complete.
18.	Replace top front upper jacket access panels and control panel
	door in reverse order.
19.	If proper ignition and burner operation is not achieved after
	checking gas supply pressure, see Cleaning and Maintenance,
	page 49 for Combustion Air Fan Adjustment. Follow the
	procedure to adjust the combustion air fans as necessary.

Figure 31 – Measuring Net Manifold Gas Pressure

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