3
FURNACE COMPONENTS
Combustion-air intake connection to ensure
contaminant-free air (right or left side).
Burner sight glass for viewing burner flame.
Burner assembly (inside). Operates with energy-
saving inshot burners and hot surface ignitor for safe,
dependable heating.
Redundant gas valve. Safe, efficient. Features 1 gas
control with 2 internal shut-off valves.
Vent outlet. Uses PVC pipe to carry vent gases from
the furnace’s combustion system (right or left side).
Inducer motor. Pulls hot flue gases through the heat
exchangers, maintaining negative pressure for added
safety.
Blower access panel safety interlock switch.
Air filter and retainer.
Condensate drain connection. Collects moisture
condensed from burned gases for disposal into home
drain system.
Heavy-duty blower. Circulates air across the heat
exchangers to transfer heat into the home.
Secondary condensing heat exchanger (inside).
Wrings out more heat through condensation.
Constructed with Polypropylene-laminated steel to
ensure durability.
Primary serpentine heat exchanger (inside).
Stretches fuel dollars with the S-shaped heat-flow
design. Solid construction of corrosion-resistant
aluminized steel means reliability.
Control center.
3-amp fuse provides electrical and component
protection.
Light emitting diode (LED) on control center. Code
lights are for diagnosing furnace operation and
service requirements.
Pressure switch(s) ensure adequate flow of flue
products through furnace and out vent system.
Rollout switch (manual reset) to prevent
overtemperature.
Junction box for 115-v electrical power supply.
Transformer (24v) behind control center provides
low-voltage power to furnace control center and
thermostat.
Limit switch (manual reset) on 58MVP only.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
3
MODELS 58MXA AND 58MCA
FURNACES (UPFLOW POSITION)
4
MODEL 58MVP
FURNACE (UPFLOW POSITION)
8
10
5
16
9
6
11
5
4
18
2
17
3
12
7
1
14
15
13
19
8
10
5
15
14
13
16
9
11
5
2
17
3
4
12
18
6
20
1
7
19
