Carrier · Infinity 98 with Greenspeed (59MN7C) · Model
Carrier Infinity 98 59MN7C 080C21–20
The 59MN7C 080C21–20 is the 80,000 BTU/h, 21-inch-wide modulating Infinity 98: input from 32,000 BTU/h minimum to 80,000 BTU/h maximum, 78,000 BTU/h maximum output, certified 97.2% AFUE upflow and horizontal. It is the modulating furnace for larger detached houses.
Rating plate
- Model
- 59MN7C 080C21–20
- Input
- 32,000 – 80,000 BTU/h
- Output
- 31,000 – 78,000 BTU/h
- AFUE
- 97.2% upflow · 95% down/horiz
- Burner
- Modulating
- Blower
- ECM, constant airflow
- Fuel
- Natural gas / Propane
- Cabinet
- 35 × 21 × 29.5 in
- Canada
- Available in Canada
This size modulates between 32,000 BTU/h minimum input (31,000 BTU/h output) and 80,000 BTU/h maximum input (78,000 BTU/h output), with Carrier certifying 97.2% AFUE upflow and horizontal and 95.0% downflow. Its certified intermediate-heat temperature rise range of 50 to 80 °F is the widest band in the family.
The 21-inch cabinet carries four burners and a 1 HP communicating constant-airflow blower reaching 2,035 CFM for cooling. The 17.5-inch sibling (080C17–14) modulates over the same input band with a 3/4 HP blower and certifies the family's slightly higher 97.4% upflow and horizontal figure.
For houses in the 80,000 BTU/h class, the modulating burner means mild-weather cycles can run at minimum fire instead of full rate, which is where this furnace's comfort argument lives. The size and control set-up still follow a heat-loss calculation; Carrier's product data repeats the standing warning against oversizing.
Specifications
From Carrier's published product data. Input and output are listed separately; AFUE depends on installation position.
| Specification | Value | Note |
|---|---|---|
| Input | ||
| Input, maximum heat | 80,000 BTU/h | |
| Input, intermediate heat | 52,000 BTU/h | |
| Input, minimum heat | 32,000 BTU/h | |
| Output | ||
| Output capacity, maximum heat | 78,000 BTU/h | Carrier product data; DOE test procedure, position dependent. |
| Output capacity, intermediate heat | 51,000 BTU/h | |
| Output capacity, minimum heat | 31,000 BTU/h | |
| Efficiency | ||
| AFUE, upflow / horizontal | 97.2 % | |
| AFUE, downflow | 95 % | |
| Airflow | ||
| Certified temperature rise, maximum heat | 40 – 70 °F (22 – 39 °C) | |
| Certified temperature rise, intermediate heat | 50 – 80 °F (28 – 44 °C) | |
| Certified temperature rise, minimum heat | 35 – 65 °F (19 – 36 °C) | |
| Airflow, maximum heat @ rated ESP | 1,285 CFM | |
| Airflow, intermediate heat @ rated ESP | 660 CFM | |
| Airflow, minimum heat @ rated ESP | 535 CFM | |
| Cooling airflow @ 0.5 in. w.c. | 2,035 CFM | |
| Cooling capacity match | 4.5 tons @ 400 CFM/ton; 5.5 tons @ 350 CFM/ton | |
| Blower motor | Communicating variable-speed, constant-airflow (VCA) ECM | Measures and holds the airflow the control requests. |
| Physical | ||
| Cabinet width | 21 in | 533 mm |
| Approximate shipping weight | 161 lb | 72.8 kg |
| Cabinet height | 35 in | 889 mm |
| Cabinet depth | 29.5 in | |
| Installation positions | Upflow, downflow, horizontal left, horizontal right | |
| Venting | ||
| Venting | Direct vent (2-pipe) or ventilated combustion air | Carrier product data lists direct-vent and ventilated-combustion-air applications for this family. |
| Electrical | ||
| Blower motor | 1 HP | |
| Maximum unit amps | 14.4 A | |
| Maximum fuse / breaker | 20 A | |
| Electrical supply | 115 V, 60 Hz, 1 phase (104 – 127 V) | |
| Controls | ||
| Burner staging | Modulating (variable-capacity gas valve) | |
| Other | ||
| Burners | 4 | |
| Inducer | Variable-speed | |
| Fuel | Natural gas; propane with gas conversion accessory | |
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 |
|---|---|---|---|---|---|---|---|---|---|---|
| 080C21–20 | 80,000 | 32,000 | 78,000 | 31,000 | 97.2 | 95 | 21 | 161 | 2035 | 1 |
| 080C17–14 | 80,000 | 32,000 | 78,000 | 31,000 | 97.4 | 95 | 17.5 | 150 | 1530 | 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
- Variable-speed inducer motor
- Condensate trap and drain components
- Constant-airflow ECM blower
- Modulating gas valve
- Control board
Service-parts list source: Components documented for service in 59MN7C product data and service literature.
Best for
- Larger detached homes wanting modulating low-fire operation in mild weather
- Communicating Infinity systems with 4.5- to 5.5-ton cooling
- Buyers comparing the Infinity 98 against a two-stage furnace at the same capacity
Compatible controls
- Communicating modulating Infinity system with Infinity Control, Infinity zoning and Infinity cooling
- 3-digit display showing fault codes and furnace status; Bluetooth and NFC service tools
- RAT and SAT thermistor connections for temperature rise
System integrations
- Infinity air conditioner or heat pump (dual-fuel) with communicating control
- Infinity zoning for single- and multiple-zone systems
- Field-supplied filter or optional media filter cabinet
Manuals, codes and service
Documents
Fault codes that apply
None documented yet.
BC Wide service
Compare
Guides that reference this model
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
What is the difference between the 080C21–20 and the 080C17–14?
Identical modulating input band and the same 78,000 BTU/h maximum output. The 080C21–20 has the wider 21-inch cabinet, a 1 HP blower with 2,035 CFM of cooling airflow and a 20 A breaker; the 17.5-inch unit certifies 97.4% versus 97.2% upflow and horizontal.
Why does this family publish three input figures?
Because it modulates. Carrier publishes maximum, intermediate and minimum heat inputs and outputs for every size; the control varies the gas rate between the minimum and maximum rather than stepping between two fixed stages.
Considering the 59MN7C 080C21–20?
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.