Installation Manual

50
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 eld
involved, see Qualications on page 6.
Do not place the water heater in operation if any part has been
under water. Immediately call a qualied 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 53.
The water heaters covered by this manual are equipped
with an electronic control system (see page 42) which
automatically sequences the Combustion Blower, pre and post
purging of the combustion chamber, the spark generator, the 24
VAC Gas Valve, Main Burner ignition, and ame 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 54 and the Sequence Of
Operation Flow Chart on page 55.
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 ll 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 ll with water.
4. Close the hot water faucet opened in Step 2 as water starts
to ow.
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 48 on page 38.
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 39
and repair any leaks found.
INITIAL START UP
PREPARATION
1. Using the control system menus, change the Operating Set
Point to the lowest temperature setting, see Operating Set
Point And Differential Adjustment on page 45.
2. Turn the water heater’s on/off switch to the “off” position.
3. Close the Main Gas Shut Off Valve, see Figure 48 on page
38.
4. Wait ve (5) minutes for any residual gas to clear.
5. Open the Main Gas Shutoff Valve.
LIGHTING THE WATER HEATER
1. Turn the water heater’s on/off switch to the “on” position.
2. Wait for the control system to complete its boot up sequence.
The Desktop screen showing the current Operating Set
Point and Tank Temperature will be displayed on the control
system’s LCD when the boot up sequence is complete.
3. Using the control system menus and UIM (user interface
module), change the Operating Set Point to a setting higher
than the current tank temperature displayed on the control
system LCD plus the Differential setting to activate a call for
heating. See Control System Operation on page 42.
4. When the 24 VAC Gas Valve is energized and the Main
Burner is ignited, the animated gas valve icon will be
displayed on the Desktop screen of the control system’s LCD
when the control system energizes the 24 VAC Gas Valve, a
animated ame icon will appear when Main Burner ignition
is successful, see the Status Icons descriptions in Table 16
on page 43.
SUPPLY GAS PRESSURE ADJUSTMENT
Fire and Explosion Hazard
Turn off gas lines during installation.
Contact a qualified installer or service
agency for installation and service.
Excessive gas pressure to gas valve can
cause serious injury or death.
Do not use water heater with any gas
other than the gas shown on the rating
label.
Supply gas pressure shall be measured while the water heater is
not ring (static pressure) AND while the water heater is ring at
full capacity (dynamic pressure).
START UP