Check For Gas Leaks - Cadet 40-120 Installation And Service Manual

10
Start-up
Purge air from heat exchanger
1. Attach a 5/16" flexible clear tube (rated for a maximum
temperature of 120°F) over the barbed nipple on the
manual air vent as shown in FIG. 10-1.
2. Fasten a wire tie (field supplied) securely around the tube
attached to the barbed nipple on the manual air vent to
keep the plastic tube from separating from the barbed
nipple when purging the system.
3. Turn the manual air vent to the open position as shown
in FIG. 10-1. Air and water should drain freely from the
system.
4. Once the water is flowing freely from the end of the hose
(water ONLY), close the manual air vent.
5. Once the valve is closed, remove the tube from the manual
air vent.
Figure 10-1 Manual Air Vent
SECURE HOSE BEFORE
OPENING VALVE
CLEAR HOSE RATED
FOR MINIMUM 120° F
VALVE OPENED
VALVE CLOSED

Check for gas leaks

Before starting the boiler, and during
WARNING
initial operation, smell near the floor and
around the boiler for gas odorant or any
unusual odor. Remove the front access
panel and smell the interior of the boiler
enclosure. Do not proceed with startup
if there is any indication of a gas leak.
Use an approved leak detection solution.
Repair any leaks at once.
DO NOT adjust gas valve outlet pressure.
WARNING
The gas valve is factory set for the correct
outlet pressure. This setting is suitable
for natural gas and propane, requiring
no field adjustment.
alter the gas valve outlet pressure could
result in damage to the valve, causing
potential severe personal injury, death, or
substantial property damage.
Propane boilers only – Your propane
WARNING
supplier mixes an odorant with the propane
to make its presence detectable. In some
instances, the odorant can fade, and the
gas may no longer have an odor. Before
startup (and periodically thereafter), have
the propane supplier verify the correct
odorant level in the gas.
(continued)
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Attempting to
Installation & Service Manual
Figure 10-2 Condensate Trap
MOUNTING NUT
FLOAT BALL
Check thermostat circuit(s)
1. Disconnect the external wire connected to the room
thermostat terminal on the connection board.
2. Connect a voltmeter across these two incoming wires.
Close each thermostat, zone valve, and relay in the external
circuit one at a time and check the voltmeter reading across
the incoming wires.
3. There should NEVER be a voltage reading.
4. If a voltage does occur under any condition, check and
correct the external wiring. (This is a common problem
when using 3-wire zone valves.)
5. Once the external thermostat circuit wiring is checked and
corrected if necessary, reconnect the external thermostat
circuit wires to the connection board.
Inspect condensate system
Inspect/check condensate lines and fittings
Inspect the condensate drain line, condensate PVC fittings and
condensate trap.
Clean/Inspect Trap Assembly
Remove the clean out cap on the bottom of the trap. Let the
condensate and any debris drain out.
HOSE BARB
CONDENSATE
DRAIN
REMOVABLE CAP TO
CLEAN OUT TRAP
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