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Figure 21 - Gas Furnace Cabinet
1.
Furnace Power Vent (PV-xx)
– An assembly used to exhaust flue gases.
2.
High-Pressure Gas Switch (PS-03)
– Monitors pressure and shuts down heating when pressures
rise above the desired set point. This is an optional component.
3.
Manifold Gas Pressure Gauge (0-10” wc)
– Measures manifold gas pressure.
4.
Manual Gas Shut Off Valve
– Allows gas flow to burner. Shut off to leak test gas train.
5.
Modulating Gas Valve (VA-03)
– Controls the amount of gas to the furnace to meet desired
discharge/space temperature.
6.
ON/OFF Gas Valve (VA-01)
– On/Off gas valve with built-in regulator and manual shut off switch.
7.
Low-Pressure Gas Switch (PS-04)
– Monitors pressure and shuts down heating when pressure
drops below the desired set point. This is an optional component.
8.
Inlet Gas Pressure Gauge
(
0-35” wc)
– Measure inlet gas pressure.
9. For standard furnaces, a stainless steel type B vent will be used. For High Efficiency (HE) furnace, a
PVC vent will be used. See
“Furnace Condensation Drain” on page 15
.
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7
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9
Typical Standard Gas Furnace
High Turndown Furnace Option
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7
5
3
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5
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5
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