EcoTemp 80% Single Stage 90K BTU Gas Furnace, WFER090B042C
The WFER090B042C is the odd one out in the WFER lineup, and usefully so: it is the only model that pairs a 3.5 ton blower with the compact 17-1/2 in. cabinet. Four monoport burners deliver 88,000 BTUH of input and 71,000 BTUH of output at 80.00% AFUE, while a 1/2 HP five-speed motor with an 11 x 8 in. wheel moves 1203 CFM in heating and 1210 CFM in cooling. For a home that needs real heating capacity and a 3.5 ton condenser but has a plenum built for 17-1/2 in., this is the size that avoids sheet metal work.
Is a 90K BTU Gas Furnace the Right Size?
Eighty-eight thousand BTUH of input, producing 71,000 BTUH delivered, covers larger single-family homes, two-story properties on one system, and colder-climate installations where design temperature is genuinely low. The 042 in the model number sets the cooling side at 3.5 tons, so this furnace is the natural indoor half of a 3.5 ton split system.
Its certified temperature rise range is 40°F to 70°F — the highest band in the WFER line alongside the 135 size. That reflects a larger burner assembly moving heat into an airflow the 17-1/2 in. cabinet can supply, and it means the duct system has more latitude before rise runs out of range. Certified external static pressure is 0.15 in. w.c. in heating and 0.50 in cooling. As with every furnace, start with a heat loss calculation, confirm the gas supply can carry 88,000 BTUH, and verify the venting arrangement before selecting.
Ideal for: Larger homes and two-story properties on a single system, colder-climate installations, and 3.5 ton system matches where the existing plenum and coil case are 17-1/2 in. wide.
Need more capacity? Step up to the 110K BTU EcoTemp WFER110C060C Gas Furnace, which adds 22,000 BTUH of input and a 5 ton blower in a 21 in. cabinet.
Recommended applications are general guidelines only. Actual furnace selection depends on a calculated heat loss, duct design, venting, gas supply and local code. Request free sizing assistance, contact Budget Heating, or call 813-885-7999.
What's Included
| Model Number | WFER090B042C — 80% AFUE Single Stage Multipoise Gas Furnace |
|---|---|
| Heating Input | 88,000 BTUH (Natural Gas) |
| Heating Output | 71,000 BTUH |
| Efficiency | 80.00% AFUE |
| Cabinet Width | 17-1/2 in. |
| Cooling Size | Up to 3.5 Ton / 42,000 BTUH |
| Airflow | 1203 CFM Heating / 1210 CFM Cooling |
| Blower Motor | 1/2 HP Direct Drive, 5 Speed, 11 x 8 in. Wheel |
| Burners | 4 Monoport |
| Certified Temperature Rise | 40°F – 70°F |
| Installation Positions | Upflow, Downflow, Horizontal-Left, Horizontal-Right |
| Ignition | Hot Surface Ignition |
| Electrical / Gas Connection | 115V-60Hz-1Ph, 8.3 Max Amps / 1/2 in. NPT |
| Vent Connection | 4 in. |
| Shipping Weight | 131 lb |
| Warranty | 1-Year Unit Replacement, 20-Year Heat Exchanger, 5-Year Parts (10-Year with Registration) |
Because the cabinet is 17-1/2 in., the same accessories as the 70K B-width furnace apply: filter rack NAHB00601FF with a 16 x 25 in. washable filter, and return air kit NAHA01701RA. On the cooling side the natural indoor match is a 3.5 ton coil such as the EcoTemp W5AM42M21XA R-454B cased coil — note its casing is 21 in., so plan the transition. The low-NOx counterpart is the EcoTemp WFEL090B042B.
Furnace & Blower Features
WFER090B042C Heating & Controls
- 88,000 BTUH input and 71,000 BTUH output at 80.00% AFUE
- Four monoport burners on hot surface ignition
- Widest certified temperature rise band in the line at 40°F to 70°F
- Electronic control center with LED diagnostics and self-test
- WhiteRodgers redundant gas valve with 1/2 in. NPT connection
- Natural gas inlet pressure 4.5 to 13.6 in. W.C.
- Solid state time operation heating blower control
- Certified for elevations from 0 to 10,000 ft
- 20-year heat exchanger limited warranty
- AHRI certified, standard NOx configuration
WFER090B042C Cabinet & Airflow
- Only WFER model combining 3.5 ton airflow with a 17-1/2 in. cabinet
- 15-7/8 in. supply outlet, 16 in. bottom inlet width
- 1/2 HP five-speed direct drive blower, 11 x 8 in. wheel, 6.8 FLA
- 1203 CFM heating, 1210 CFM cooling on as-shipped taps
- Certified external static pressure 0.15 heating / 0.50 cooling
- Air delivery chart documents all five taps out to 1.0 in. w.c.
- Four-position installation from the same carton
- 4 in. vent connection, common ventable with other gas appliances
- 8.3 max amps, 11.0 ampacity, 15 amp maximum breaker
- 131 lb shipping weight
Specifications & Manuals
Physical data for size 090B042 covers input and output capacity, temperature rise, electrical ratings and blower data. The air delivery table gives CFM by speed tap and external static, and the accessory list confirms which filter rack and return air kit fit the 17-1/2 in. cabinet.
Frequently Asked Questions
Why is the WFER090B042C rated for 3.5 tons of cooling?
The 042 digits in the model number are the cooling size code — 42,000 BTU/hr, 3.5 ton. It is the only furnace in the WFER range that fits a 3.5 ton blower into the 17-1/2 in. cabinet.
How many burners does this furnace have?
Four monoport burners, up from three on the 70K sizes. Burner count scales with input: two on the 45K, three on the 70K, four on the 90K, five on the 110K and six on the 135K.
What is the certified external static pressure?
0.15 in. w.c. in heating and 0.50 in. w.c. in cooling. The air delivery table extends to 1.0 in. w.c. so you can see how much airflow is lost as duct restriction climbs.
What electrical circuit does this furnace need?
115V, 60Hz, single phase, with 8.3 maximum unit amps and 11.0 ampacity. Minimum wire size is 14 gauge with a maximum 15 amp time-delay fuse or breaker, and maximum one-way wire length is 33 ft.
Which cased coil pairs with a 3.5 ton WFER090B042C?
Any AHRI-certified 3.5 ton coil for the outdoor unit — the EcoTemp W5AM42M21XA is the current R-454B option. Its casing is 21 in. against the furnace's 17-1/2 in., so a coil adapter or transition is needed.
Can this furnace be installed horizontally in an attic?
Yes, horizontal-left or horizontal-right. In the horizontal position only line contact is permitted between the top and two sides of the furnace jacket and building joists, studs or framing — see the clearances diagram in the installation instructions.
WFER Technical Specifications
