A.O. Smith FVIR Configuration guide

FVIR WATER HEATER CLEANING INSTRUCTIONS
To perform the cleaning instructions below the following tools
are needed:
• Vacuum cleaner with hose attachment.
• Flame arrestor cleaning attachment.
• Flashlight
• Small mirror approximately 2”x3”.
• 3/8”, 7/16”, and 3/4” open end wrenches.
• 3/8” nut driver
• Small container of soapy water and an applicator.
Like other appliances, your water heater will need occasional
servicing to maintain peak performance. Sufficient air flow
is crucial to the proper operation of your water heater. This
publication addresses one possible cause of restricted air
flow, and the procedure for its prevention and correction.
Signs of restricted air flow are yellow flames, pilot outage,
sooting, or unstable flame. Before starting, consult the
sections of your owner’s manual dealing with condensation,
air requirements, gas supply, venting, and cleaning the air
intake screen. Also, make sure that your heater is properly
sized for your home. An undersized heater may result in
condensation which can drip onto the flame causing a pilot
outage. Your water heater is built to the current industry
safety standard and meets all FVIR (flammable vapor ignition
resistant) requirements. This assures that any flammable
vapors drawn into the combustion chamber and ignited can
not ignite remaining flammable vapors on the exterior of the
heater causing a fire or explosion. This design includes a
flame arrestor and one or two air intake screen(s), see Figure 1.
Figure 1
These screen(s) prevent larger particles of dust or lint from
entering the heater, thus restricting air flow and causing
improper combustion. The owner’s manual asks you to
visually check and clean the screen(s) as necessary. Smaller
particles may pass through these screens and lodge in the
flame arrestor.
This document will cover 2 levels of cleaning. The first will
cover the steps necessary to clean under the water heater,
where combustion air is drawn in through the air intake
screen(s) and flame arrestor. The second will cover the steps
necessary to clean the combustion chamber.
Procedure: Level 1
1. Turn the water heater gas control knob to “off” and allow
the burner area to cool, see Figure 2.
GAS CONTROL KNOB
TOP
VIEW
Figure 2
2. Remove the plastic air intake screen(s) and use a small
mirror and flashlight to view the bottom of the flame
arrestor.
3. Using the flame arrestor cleaning attachment, vacuum
all dust and other particles from beneath the heater, see
Figure 3.
4. To clean the bottom of the flame arrestor, turn the flame
arrestor cleaning attachment over and insert it through
the air intake opening at the base of the heater, and use
a gentle sweeping motion to clean the entire base, see
Figure 3.
FLAME ARRESTOR
CLEANING ATTACHMENT
AIR INTAKE
OPENINGS
Figure 3
5. Re-insert the air intake screen when finished.
6. At this point, relight the pilot, and check heater for
operation. Allow an entire heating cycle to complete to
assure proper operation.
NOTE:Iftheoriginal filterscreen ismissing ordamaged, oryou
have an installation that frequently gets lint or dust buildup, we
recommend the installation of a larger capacity filter screen. If
you have questions, contact Residential Technical Assistance
referencing the number in your manual.
186210-000
FVIR-Cleaning.pdf Applies to AO Smith line of products
http://waterheatertimer.org/troubleshoot-flammable-vapor-on-gas-water-heater.html

Procedure: Level 2
1. Turn the water heater gas control knob to “off” and allow
the burner area to cool completely, approximately 15
minutes, see Figure 2.
2. Turn off the supply gas at the supply gas line if
applicable.
3. Disconnect the three connections from the bottom of the
gas valve, being careful to note their location, see Figure 3.
WARNING!
Do not bend the gas valve connections too far; doing so
may result in damage.
Robertshaw Gas Valve
THERMOCOUPLE
MANIFOLD TUBE
PILOT
TUBE
THERMOCOUPLE
MANIFOLD TUBE
PILOT
TUBE
White Rodgers Gas Valve
Figure 3
4. Remove the outer door from around the burner tubing at
the base of the water heater. White-Rodgers Gas Valve:
Remove the Piezo igniter (with the orange wire) from the
gas valve by sliding it back toward the tank (leave the
orange wire in the inner door assembly). Robertshaw
Gas Valve: Disconnect the igniter wire at the base of
igniter button.
5. Remove the 3/8” manifold door nuts, holding the inner
door and white gasket in place, see Figure 4.
Figure 4
6. Carefully remove the burner from the combustion
chamber. Scale or other materials may have collected
on the top of the main burner; try not to dump any
debris off of the burner until it and the inner door have
been removed from the heater. TAKE CARE NOT TO
DAMAGE THE WHITE GASKET ON THE INSIDE OF
THE INNER DOOR.
7. Inspect the radiation shield (thin circular metal sheet
under the burner and above the flame arrestor), see
Figure 5. If any of the sides of the radiation shield are
touching the base (disrupting air flow), install 1/4-inch
high feet under the radiation shield. To obtain the feet
free of charge, contact Residential Technical Assistance
referencing the number in your manual.
Figure 5
8. Vacuum the main assembly and pilot burner assembly.
Then vacuum the top of the radiation shield located
inside the burner chamber. Using the flame arrestor
cleaning attachment, clean the inside of the combustion
chamber and the exposed area of the flame arrestor.
9. Re-insert the burner taking care that the main burner
tube is seated in the burner positioning bracket.
10. Carefully reposition the inner door w/gasket over the
bolts on the combustion chamber. Do not tighten the
nuts down until the main burner, pilot burner, and
thermocouple are attached and tightened.
11. Make sure that the white fibrous door gasket is not
folded over and protrudes out from the inner door in all
directions.
Fire and Explosion Hazard
Failure to do so can result in death, explosion or fire.
• Tighten both manifold door nuts
securely.
• Remove any debris between inner
door and combustion chamber.
• Replace viewport if glass is
missing or damaged.
• Replace door gasket if damaged.
12. Then tighten the 3/8” nuts to hold the inner door in place.
Check the gas connections for proper fitting and then
light the pilot, following the directions on the side of the
heater.
13. Once the pilot is lit, turn the valve to the “ON” position
and ignite the main flame. Brush soapy water on the gas
connections and look for bubbling. This is an indication
of a gas leak. If bubbles appear, shut off gas supply
and check fittings. Re-light the pilot and check for leaks
again, repeating the soapy water solution method.