Gas Pressure Checks. LB White L.B. White Therma Grow Greenhouse Heaters HW120

16

Gas Pressure Checks

WARNING n

Do not disassemble the gas control valve.

n

Do not attempt to replace any components of the gas control valve.

n

The gas control valve must be replaced if any physical damage occurs to the control valve assembly.

n

Failure to follow this warning will result in fire or explosions, leading to injury or death to humans, and property damage.

2.

Securely connect a pressure gauge to each pressure tap.

3.

Open the fuel supply valves to the heater and reconnect the heater electrical supply.

4.

Start the heater

C. Reading Pressures

1.

With the heater operating, the pressure gauges should read the pressures specified on the dataplate .

2.

Do the readings at the inlet and outlet pressure gauges agree with that specified on the dataplate?

If so, then no further checking or adjustment is required. Proceed to section D.

ATTENTION

n

The following explains a typical procedure to be followed in checking gas pressures.

n

The gas pressures will vary depending upon fuel type.

n

Consult the dataplate on the heater or page 4 in this manual for specific pressures to be used in conjunction with this procedure.

n

Gas pressure measured at the inlet to the gas valve is

Inlet Pressure and gas pressure measured at the outlet of the gas valve is Burner Manifold Pressure.

3.

If the inlet pressures do not agree with that specified on the dataplate, then the regulator controlling gas pressure to the heater requires adjustment.

4.

If the inlet pressures are correct and the burner manifold pressure does not agree with that specifed on the dataplate, then the gas control valve’s internal pressure regulator requires adjustment. See Fig. 15 for regulator location.

FIG. 15

A. Preparation

1.

Obtain two pressure gauges capable of reading up to

35 in. W.C.

INTERNAL PRESSURE REGULATOR

LOW PRESSURE GUAGE

OUTLET PRESSURE TAP

ON

LOW PRESSURE GUAGE

OFF

2.

Disconnect the heater from the electrical supply and close the fuel supply valve to the heater inlet.

INLET PRESSURE TAP

3.

Open the burner access panel.

4.

Brush or blow off any dust and dirt on or in the vicinity of the gas control valve.

B. Gauge Installation

TYPICAL PRESSURE GAUGE INSTALLATION. ALWAYS

REFER TO DATA PLATE FOR FUEL TYPE AND

PRESSURE REQUIREMENTS.

D. Completion

1.

Locate the inlet and outlet pressure taps, see Fig. 14.

Remove the pressure tap plug using a 3/16 in. allen key.

1.

Once the proper inlet and burner manifold pressures have been confirmed and/or properly set, close the fuel supply valve to the heater and allow the heater to burn off any gas remaining in the gas supply line.

FIG. 14

TAP 2.

Disconnect the heater from its electrical supply.

ON

3.

Remove the gauges and connecting hoses.

4.

Install pressure tap plugs and tighten securely. Check for gas leaks.

OFF

INLET PRESSURE TAP