69-1088B
7
D896 AUTOMATIC VENT DAMPER
EXHIBIT B
Procedure for Installing Electrically Operated Automatic Vent Damper Devices
on Existing Appliances
This procedure is intended as a guide to aid in safely installing an electrically operated or mechanically actuated
automatic vent damper device on an existing appliance.
This procedure is based on the assumption that the history of the specific appliance has been one of safe and
satisfactory operation.
This procedure is predicated on central furnace, boiler and water heater installations, and it should be recognized that
generalized procedures cannot anticipate all situations. Accordingly, in some cases deviation from this procedure may
be necessary to determine safe operation of the equipment.
The following steps are to be followed in making the modifications:
1. Perform a safety inspection of the existing appliance installation. See Exhibit A for the recommended procedure
for such a safety inspection.
2. Shut off all gas and electricity to the appliance.
To shut off gas use the shutoff valve in the supply line to the
appliance.
3. Install the automatic vent damper device in strict accordance with the manufacturer’s installation instructions.
Make certain the device is not located in that portion of the venting system which serves any appliance other than the
one for which the damper is installed.
4. Make certain wiring connections are tight and wires are positioned and secured so they will not be able to contact
high temperature locations.
5. When an additional automatic valve has been incorporated or an existing gas control replaced, conduct a gas
leakage test of the appliance piping and control system downstream of the shutoff valve in the supply line to the
appliance.
6. Visually inspect the modified venting system for proper horizontal pitch.
7. Check that the damper and gas valve(s) are in the correct operating sequence.
(a)The damper must be in the full open position before the gas valve(s) opens.
(b)The damper must remain in the full open position while the gas valve(s) is open.
(c) The gas valve(s) must be closed before the damper
begins
its return to the closed position.
(d)The damper shall remain in the closed position during the off cycle of the appliance.
8. Determine the amperage draw of the gas control circuit and damper device.
(a)Check appliance transformer for adequate capacity.
(b)Check heat anticipator in comfort thermostat to determine it is properly adjusted.
9. Sequence the appliance through at least three normal operating cycles.
10. Insofar as is practical, close all building doors and windows and all doors between the space in which the appliance
is located and other spaces of the building. Turn on clothes dryers. Turn on any exhaust fans, such as range hoods and
bathroom exhausts, so they will operate at maximum speed. Do not operate a summer exhaust fan. Close fireplace
dampers.
11. Place appliance in operation.
Follow the lighting instructions.
Adjust thermostat so appliance will operate
continuously.
12. Test for spillage at the draft hood relief opening after 5 minutes of main burner operation. Use the flame of a match
or candle, or smoke from a cigarette, cigar or pipe.
13. (a) Visually determine that main burner gas is burning properly; i.e., no floating, lifting or flashback. Adjust the
primary air shutter(s) as required.
(b) If the appliance is equipped with high and low flame controlling or flame modulation, check for proper main
burner operation at low flame.
14. Determine that the pilot(s), when provided, is burning properly and that main burner ignition is satisfactory by
interrupting and reestablishing the electrical supply to the appliance in any convenient manner.
If the appliance is equipped with a continuous pilot(s), test the pilot safety device(s) to determine if it is operating
properly by extinguishing the pilot(s) when the main burner(s) is off and determining, after 3 minutes, that the main burner
gas does not flow upon a call for heat.
If the appliance is not provided with a pilot(s), test for proper operation of the ignition system in accordance with the
appliance manufacturer’s lighting and operating instructions.
15.
Applicable only to furnaces
—Check both the limit control and the fan control for proper operation. Limit control
operation can be checked by blocking the circulating air inlet or temporarily disconnecting the electrical supply to the
blower motor and determining that the limit control acts to shut off the main burner gas.
16.
Applicable only to boilers
—
(a) Determine that the water pumps are in operating condition.
(b) Test low water cutoffs, automatic feed controls, pressure and temperature limit controls, and relief valves in
accordance with the manufacturer’s recommendations to determine they are in operating condition.
17. Label the damper device (see 1.7.5) with information as to:
(a) Name of qualified agency responsible for damper installation.
(b) Date of installation.
Exhibit B of ANSI Standard Z21.66-1994 for Electrically Operated Automatic Vent Damper Devices
for use with Gas-Fired Appliances.
