Carrier · Comfort 96 (59SC6A) · Model
Carrier Comfort 96 59SC6A 080M21–20
The 59SC6A 080M21–20 is the 80,000 BTU/h, 21-inch-wide Comfort 96: 78,000 BTU/h output on a single gas rate, 96.5% AFUE upflow, with a 1 HP multi-speed ECM blower that can move air for a 5-ton coil. It is the entry-tier size for larger detached houses.
Rating plate
- Model
- 59SC6A 080M21–20
- Input
- undefined – 80,000 BTU/h
- Output
- undefined – 78,000 BTU/h
- AFUE
- 96.5% upflow · 95% down/horiz
- Burner
- Single-stage
- Blower
- ECM, constant torque (variable-speed)
- Fuel
- Natural gas / Propane
- Cabinet
- 35 × 21 × 29.5 in
- Canada
- Available in Canada
This is the Comfort 96 size a heat-loss calculation lands on for larger or older detached houses: 80,000 BTU/h in, 78,000 BTU/h out at full fire on every call. Because it is single-stage, there is no low fire to soften the cycles; the thermostat decides when it runs, and the furnace runs flat out until satisfied.
The 21-inch cabinet and 1 HP MCT ECM blower deliver up to 2,125 CFM for cooling, which is why this width is chosen when a large air conditioner or heat pump shares the ductwork. The narrower 17.5-inch sibling (080M17–16) delivers the same 78,000 BTU/h with a 3/4 HP blower, certified at the same 96.5% upflow.
An 80,000 BTU/h input is a large appliance for a single gas rate. Where the house spends most of the heating season needing far less than full fire, Carrier's two-stage Performance 96 tends to serve the same house more evenly, and the cost comparison belongs in the proposal rather than in the brochure.
Specifications
From Carrier's published product data. Input and output are listed separately; AFUE depends on installation position.
| Specification | Value | Note |
|---|---|---|
| Input | ||
| Input | 80,000 BTU/h | |
| Output | ||
| Output capacity | 78,000 BTU/h | Carrier product data; DOE test procedure, position dependent. |
| Efficiency | ||
| AFUE, upflow / horizontal | 96.5 % | |
| AFUE, downflow | 95 % | |
| Airflow | ||
| Certified temperature rise range | 40 – 70 °F (22 – 39 °C) | |
| Airflow, heating @ rated ESP | 1,310 CFM | |
| Cooling airflow range | 225 – 2125 CFM | |
| Blower motor | Multi 18-speed, constant-torque (MCT) ECM | Not a communicating constant-airflow motor; speeds are installer-selectable. |
| Physical | ||
| Cabinet width | 21 in | 533 mm |
| Shipping weight | 158 lb | 72 kg |
| Cabinet height | 35 in | 889 mm |
| Cabinet depth | 29.5 in | 750 mm |
| Installation positions | Upflow, downflow, horizontal left, horizontal right | |
| Venting | ||
| Venting | Direct vent (2-pipe), single-pipe, or ventilated combustion air on sizes above 26,000 BTU/h; the 26,000 BTU/h size uses 2-pipe venting with outside combustion air and is not classed as direct-vent | |
| Electrical | ||
| Blower motor | 1 HP | |
| Maximum unit amps | 13.1 A | |
| Maximum fuse / breaker | 15 A | |
| Electrical supply | 115 V, 60 Hz, 1 phase (104 – 127 V) | |
| Controls | ||
| Burner staging | Single-stage (full fire on every call) | |
| Other | ||
| Burners | 4 | |
| Inducer | Single-speed | |
| Fuel | Natural gas; propane with gas conversion accessory kit | |
Variants
Sizes that share this model page. A variant gets its own page only when it has substantial independent value.
| Size | Input high | Input low | Output high | Output low | AFUE upflow | AFUE down/horiz | Width (in) | Ship wt (lb) | Cooling CFM | Motor HP |
|---|---|---|---|---|---|---|---|---|---|---|
| 080M21–20 | 80,000 | — | 78,000 | — | 96.5 | 95 | 21 | 158 | 225 – 2125 | 1 |
| 080M17–16 | 80,000 | — | 78,000 | — | 96.5 | 95 | 17.5 | 150 | 370 – 1625 | 3/4 |
Filters, serial numbers and service parts
Filter
- Field-supplied filter; certified watt data uses Carrier media filter 325531-40
Components this family's service documentation covers
- Hot-surface ignitor
- Flame sensor
- Pressure switches
- Inducer motor
- Condensate trap and drain components
- ECM blower motor
- Control board
Service-parts list source: Components documented for service in 59SC6A-01SI REV D.
Fault codes this model can show
Best for
- Larger detached homes whose heat-loss calculation supports 78,000 BTU/h of output
- Houses with a 4- to 5-ton air conditioner or heat pump on shared ductwork
- Budget-conscious replacements where full-fire cycles are acceptable
Compatible controls
- Standard 24 V thermostat terminals: G, C, W, Y, R
- On-board 3-digit status display with NFC setup via the Carrier service technician app
- EAC-1 (115 VAC), HUM (24 VAC) and 1-stage AC accessory connections
System integrations
- Air conditioner or heat pump (dual-fuel / Hybrid Heat) with a compatible thermostat
- Twinning of two furnaces with the accessory kit (selected sizes only)
- Manufactured (mobile) home applications with the MH accessory kit (selected sizes)
- Field-supplied filter or optional media filter cabinet
Manuals, codes and service
Documents
- 59SC6A Product Data — Comfort 96, Single-Stage, Multi 18-Speed ECM (59SC6A-01PD REV B)
- 59SC6A Installation, Start-up, Operating and Service and Maintenance Instructions (59SC6A-01SI REV D)
Fault codes that apply
- Code 23: pressure switch stuck closed
- Code 24: fuse fault
- Code 25: control program and configuration faults
- Code 27: super plug or control program fault
- Code 31: secondary pressure switch open or lockout
- Code 32: open main pressure switch (LPS)
- Code 33: a switch has opened in the main limit circuit
- Code 34: ignition fault or flame loss
- Code 45: control failure
- Code 46: momentary loss of power
- Code 10: rapid flash - L1 polarity fault
- Code 12: W on at power up
- Code 13: limit lockout or ignition lockout
- Code 14: flame-loss lockouts during a heat request
- Code 21: 24 VAC sensed on the gas valve when it shouldn't be
- Code 22: false flame
BC Wide service
This catalogue page is reference information for anywhere in Canada. On-site service for this model is available across Greater Vancouver from BC Wide's Burnaby base — see furnace service in Burnaby and all service areas.
Questions people ask
Should I step up to the two-stage furnace at this size?
Worth comparing: at 80,000 BTU/h a single-stage furnace fires hard on every call, while the two-stage Performance 96 carries most mild-weather cycles on low fire. The difference is comfort and noise more than gas use, since both are 95%+.
Does this size need a 20-amp circuit?
No. Carrier's product data lists a 15 A maximum fuse or circuit breaker with 14 AWG minimum wire for every 59SC6A size, including this one.
Considering the 59SC6A 080M21–20?
Get a published ballpark range for a supply-and-install, then a consultation to confirm sizing from a heat-loss assessment. Equipment-only pricing is not offered on this site.