Adjustments; Checking Venting; Checking The Input - AO Smith BTR120 Manuel D'instructions

ADJUSTMENTS

ON INITIAL STARTUP SOME ADJUSTMENTS MAY BE NECESSARY.
Check Manifold and inlet gas pressures (see GAS SUPPLY
SYSTEMS on page 13 and CHECKING THE INPUT on page 29-30.)
Check Pilot Burner (See Pilot Burner section on page 34.)
TESTING DAMPER OPERATION
With the Service Switch in the AUTOMATIC OPERATION
position, check the operation of the flue damper three (3) times
with the water operating controls for proper operating sequence:
• The damper disc must be open (in the vertical position) before
the ignition and combustion process begins.
• The damper disc must be in the open position when the main
burner is firing.
• The gas control valve must close and the main burner must
have ceased firing before the damper disc begins its return to
the closed (horizontal) position.
If during testing of the operation of the damper you find that
there is a problem with the operation of the water heater when
the Service Switch is in the AUTOMATIC OPERATION position:
Reset the Service Switch to the HOLD OPEN DAMPER position
and check operation again.
If the water heater does operate when placed in the HOLD OPEN
DAMPER position:
• Refer to the EFFIKAL RVGP-FSF-SERIES TROUBLESHOOTING
GUIDE on page 37.
If the water heater does not operate with the Service Switch in
either position:
• Refer to the Troubleshooting Sections and Troubleshooting
Checklist.

CHECKING VENTING

The following steps shall be followed with each appliance connected
to the venting system placed in operation, while any other appliances
connected to the venting system are not in operation.
1. Seal any unused openings in the venting system.
2. Inspect the venting system for proper size and horizontal pitch, as
required in the National Fuel Gas Code, ANSI Z223.1or the CAN/
CGA B149 Installation Codes and these instructions. Determine
that there is no blockage or restriction, leakage, corrosion and
other deficiencies which could cause an unsafe condition.
3. So far as is practical, close all building doors and windows
and all doors between the space in which the water heater(s)
connected to the venting system are located and other spaces
of the building. Turn on all appliances not connected to the
venting system. Turn on all exhaust fans, such as range hoods
and bathroom exhausts, so they shall operate at maximum
speed. Close fireplace dampers.
4. Follow the lighting instruction. Place the water heater being
inspected in operation. Adjust thermostat so water heater shall
operate continuously.
5. Test for draft hood spillage at the relief opening after 5 minutes
of main burner operation.
6. After it has been determined that each appliance connected to
the venting system properly vents when tested as outlined above,
return doors, windows, exhaust fans, fireplace dampers and any
other gas burning appliance to their previous conditions of use.
7. If improper venting is observed during any of the above tests,
the venting system must be corrected.
FAILURE TO CORRECT BACK DRAFTS MAY CAUSE AIR
CONTAMINATION AND UNSAFE CONDITIONS.
• If the back draft cannot be corrected by the normal method or
if a suitable draft cannot be obtained, a blower type flue gas
exhauster must be employed to assure proper venting and
correct combustion.

CHECKING THE INPUT

For installation locations with elevations above 2000 feet, refer
to HIGH ALTITUDE INSTALLATIONS section of this manual for
input reduction procedure.
1. Attach a pressure gauge or a manometer to the manifold
pressure tap on the gas control valve and refer to Table
9, for correct manifold pressure.
2. Use this formula to "clock" the meter. Be sure that other
gas consuming appliances are not operating during this
interval.
(3600/T) x H = Btuh
T = Time in seconds to burn one cubic foot of gas.
H = Btu's per cubic foot of gas.
Btuh = Actual heater input.
Example: (Using BTR-250 heater)
T = 15.1 seconds
H = 1050 Btu
Btuh = ?
(3600/15.1) x 1050 = 250,000 (Compare with BTR-250 model
and rating.)
APPROXIMATE TIME REQUIRED TO CONSUME
1 CU. FT. OF GAS AT FULL CAPACITY
INPUT TYPE
RATE OF
(BTUH) GAS
NATURAL
120,000
PROPANE
NATURAL
154,000
PROPANE
NATURAL
180,000
PROPANE
NATURAL
199,000
PROPANE
NATURAL
250,000
PROPANE
NATURAL
251,000
PROPANE
NATURAL
275,000
PROPANE
NATURAL
305,000
PROPANE
NATURAL
365,000
PROPANE
NATURAL
390,000
PROPANE
29
TABLE 9.
BTUH TIME REQ'D TO
PER CONSUME 1 CU.
CU. FT. FT. OF GAS
1050 31. 5 SEC.
2500 75.0 SEC.
1050 24.5 SEC.
2500 58.4 SEC.
1050 21.0 SEC.
2500 50.0 SEC.
1050 19.0 SEC.
2500 45.2 SEC.
1050 15.1 SEC.
2500 36.0 SEC.
1050 15.1 SEC.
2500 35.9 SEC.
1050 13.7 SEC.
2500 32.7 SEC.
1050 12.4 SEC.
2500 29.5 SEC.
1050 10.4 SEC.
2500 24.7 SEC.
1050 9.7 SEC.
2500 23.1 SEC.