Lochinvar CLN 120080 Instruction Manual Download Page 25

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PRIOR TO START UP

Installation and start up of this water heater requires abilities

and skills equivalent to that of a licensed tradesman in the field

involved, see Qualifications on page 6.
Do not place the water heater in operation if any part has been

under water. Immediately call a qualified service technician to

inspect the water heater and to replace any part of the control

system and any gas control which has been under water.
Light the water heater in accordance with the Lighting and

Operation Instruction label on the water heater and in this manual

on page 27.
The water heaters covered by this manual are equipped with

an electronic control system that automatically sequences the

Blower, the Igniter, the 24 VAC Gas Valve, Burner ignition,

and flame sensing. The control system will lock out after three

unsuccessful ignition attempts.
Before attempting start up, thoroughly study and familiarize

yourself with the exact Sequence Of Operation, see the written

Sequence Of Operation on page 27 and the Sequence Of

Operation Flow Chart on page 28.
Be certain that the water heater is full of water, that air is purged

from the gas and water lines and that there are no leaks in the

gas and water lines. Ensure all inlet water valves are open.

Filling The Water Heater

Follow these steps to fill the water heater prior to start up.
1. Close the heater drain valve.
2. Open a nearby hot water faucet to permit the air in the system

to escape.

3. Fully open the cold water inlet valve allowing the piping and

water heater to fill with water.

4. Close the hot water faucet opened in Step 2 as water starts to flow.

Supply Gas Line Purging

Fire or Explosion Hazard

Read instruction manual before

installing, using or servicing

water heater.

To avoid risk of fire or explosion purge discharge must not

enter into confined areas or spaces where ignition can occur.
The area must be well ventilated and all sources of ignition

must be deactivated or removed.

Gas line purging is required with new piping or systems in

which air has entered.

Use only the gas shown on the water heater rating label.
Keep ignition sources away from faucets after extended

periods of non-use.

1. Close the Main Gas Shutoff Valve, see Figure 21 on page 24.
2. Purge all air from the supply gas line up to the water heater’s

Main Gas Shutoff Valve.

3. When all air has been purged from the supply gas line, tighten

all supply gas line connections.

4. Check for gas leaks, see Gas Line Leak Testing on page 24

and repair any leaks found.

START UP

INITIAL START UP

Required Test Equipment

U-tube manometer, pressure gauge, or digital manometer.

Recommended range: 20” W.C. (5 kPa).

NOTE:

All test equipment must be acclimated to ambient

temperature before calibration and use.

Preparation

1. Adjust the thermostat to the lowest temperature setting.
2. Turn the water heater’s on/off switch to the “off” position.
3. Close the Main Gas Shut Off Valve, see Figure 21 on page 24.
4. Wait five (5) minutes for any residual gas to clear.
5. Open the Supply Gas Pressure Port on the gas control valve

by turning the center screw counter-clockwise. Connect the

manometer to the supply gas pressure test port, see Figure 22.

6. Open the Main Gas Shutoff Valve.
7. Measure and record the supply gas pressure, this is a “static”

supply gas pressure reading; while the water heater is not firing.

FIGURE 22. – TOP VIEW

Lighting The Water Heater

1. Turn the water heater’s on/off switch to the “on” position.

2. Adjust the thermostat to the desired water temperature.

3. Record the supply gas pressure when the 24 VAC Gas Valve is

energized and the Burner is operating. This is a “dynamic” gas

pressure reading; while the water heater is firing.

4. Compare the actual supply gas pressure reading recorded