Table of Contents
Advertisement
Safety Inspection
1. Check all thermostats and high limit settings.
2. During the following safety checks leave manome-
ters hooked up, check and record.
3. If other gas-fired appliances in the room are on the
same gas main, check all pressures on the MVB with
all other equipment running.
4. Check thermostats for ON-OFF operation.
5. Check high limits for ON-OFF operation.
6. While in operation, check flow switch operation.
7. Check the low gas pressure switch (if provided). (For
proper adjustment, use the attached manometers, if
available, to set pressure. The scales on the switch
are approximate only.) Low gas pressure switch (if
provided) must be set at 3.0 in. WC for natural gas
and propane gas.
8. Make sure that the high gas pressure switch is set
to 3.0 in. WC for both natural gas and propane gas.
Finishing
1. Record all data on the "Start-up Checklist" located at
the back of this manual.
2. Disconnect the manometers and reconnect the cap
on the fan pressure tee and reinsert the sealing
screws into the bleedle valves.
3. Start-up is complete and the heater should be
operating properly.
Follow-Up
1. Safety checks must be recorded as performed.
2. Turn heater on. After main burner ignition:
3. Check manometer for proper readings.
4. Cycle heater several times and re-check readings.
5. Remove all manometers and replace caps and
screws.
6. Check for gas leaks one more time.
44
Leak Test Procedure: Dual-Seat Gas Valve
Proper leak testing requires three pressure test points in
the gas train. Remove the upper front panel and swing
the front J-box out of the way to access the gas valve for
this test.
Test point A is a bleedle valve located upstream of the
combination gas valve on the supply manifold.
Test point B is a bleedle valve located between the two
automatic gas valve seats.
Test point C is a bleedle valve located downstream of both
automatic gas valve seats and upstream of the manual
valve. See Figure 44.
These tests are to be conducted with the electrical power
to the heater turned OFF.
1. Manually close the downstream leak test valve.
2. Open the bleedle valve at test point A and connect
a manometer to it. Verify that there is gas pressure
and that it is within the proper range (NOTE: must
not exceed 14.0 in. WC).
3. Open test point B and connect a rubber tube to it.
Connect the other end of the tube to a manometer
and look for a build-up of pressure. Increasing
pressure indicates a leaking gas valve which must
be replaced.
4. Next, close the upstream manual gas valve (field
supplied) and remove the manometers from the
bleedle valves in test point A and test point B.
Connect a rubber tube from the test point A bleedle
valve to the test point B bleedle valve and open the
upstream manual gas valve. Make sure that test
point A & B bleedle valves have been opened so as
to allow gas to flow. This will bring gas pressure to
the second valve seat.
5. Open the bleedle valve at test point C and connect
a second rubber tube to it. Connect the other end
of the tube to a manometer and look for a build-up
of pressure. Increasing pressure indicates a leaking
gas valve which must be replaced.
6. Remove rubber tube and manometers. Close each
bleedle valve as the tubes are removed.
7. After no leakage has been verified at all valve seats
and test valve, open downstream leak test valve and
restore electrical power to the heater.
Advertisement
Table of Contents
