EcoTemp 80% Single Stage 45K BTU Gas Furnace, WFER045A036C
The WFER045A036C is the entry point of the EcoTemp WFER line — 44,000 BTUH of natural gas input producing 36,000 BTUH of output at 80.00% AFUE, packed into the narrowest cabinet the series offers at 14-3/16 in. wide. Two monoport burners, hot surface ignition, an electronic control center with LED diagnostics and self-test, and a 1/3 HP five-speed direct drive blower sized for up to 3 tons of cooling make it a complete small-home heating platform. Like every furnace in the line it is a four-position design, installing upflow, downflow, horizontal-left or horizontal-right from the same box.
Is a 45K BTU Gas Furnace the Right Size?
At 44,000 BTUH input and 36,000 BTUH delivered, this furnace suits small homes, condos, additions and mild-climate installations where the heating load is modest and the cooling side does the heavy lifting. The blower is rated at 710 CFM on the heating speed tap and 1080 CFM on cooling, so it supports a 3 ton air conditioner or heat pump coil while keeping the heating side properly matched.
Furnace sizing comes from a heat loss calculation, not from square footage or from whatever was there before. Oversizing an 80% furnace produces short cycles, uneven room temperatures and premature component wear; undersizing leaves the house cold on design nights. Envelope tightness, window area, ceiling height, duct location and climate zone all move the number. Also confirm the certified temperature rise range of 30°F to 60°F can be met by your duct system — a restrictive return will push rise above the top of the band regardless of how well the load was calculated.
Ideal for: Condos, townhomes, small single-family homes, additions and guest suites in mild and moderate climates, and narrow utility closets where a 14-3/16 in. cabinet is the widest that will fit.
Need more capacity? Step up to the 70K BTU EcoTemp WFER070A036C Gas Furnace, which adds 22,000 BTUH of input in the identical 14-3/16 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 | WFER045A036C — 80% AFUE Single Stage Multipoise Gas Furnace |
|---|---|
| Heating Input | 44,000 BTUH (Natural Gas) |
| Heating Output | 36,000 BTUH |
| Efficiency | 80.00% AFUE |
| Cabinet Width | 14-3/16 in. |
| Cooling Size | Up to 3 Ton / 36,000 BTUH |
| Airflow | 710 CFM Heating / 1080 CFM Cooling |
| Blower Motor | 1/3 HP Direct Drive, 5 Speed, 10 x 6 in. Wheel |
| Burners | 2 Monoport |
| Certified Temperature Rise | 30°F – 60°F |
| Installation Positions | Upflow, Downflow, Horizontal-Left, Horizontal-Right |
| Ignition | Hot Surface Ignition |
| Electrical / Gas Connection | 115V-60Hz-1Ph, 5.6 Max Amps / 1/2 in. NPT |
| Vent Connection | 4 in. |
| Shipping Weight | 104 lb |
| Warranty | 1-Year Unit Replacement, 20-Year Heat Exchanger, 5-Year Parts (10-Year with Registration) |
Ships configured for natural gas at 0 to 10,000 ft with a size 43 factory orifice; a propane conversion kit (AGAGC8NPS01A) is required for LP. A filter is required on every return-air inlet — the matching external bottom filter rack is NAHB00501FF, which includes a 14 x 25 in. washable filter, and NAHA01401RA is the 14-3/16 in. return air kit. Pair the furnace with a matching cased evaporator coil and browse the rest of the 80% metal-vented furnace range.
Furnace & Blower Features
WFER045A036C Heating & Controls
- 44,000 BTUH input, 36,000 BTUH output, 80.00% AFUE
- Two monoport burners with hot surface ignition
- Electronic control center with LED diagnostics and self-test
- Adjustable heating air temperature rise, certified 30°F to 60°F
- WhiteRodgers redundant gas valve, 4.5 to 13.6 in. W.C. natural gas inlet
- Size 43 factory-installed orifice, certified 0 to 10,000 ft
- Solid state time operation heating blower control
- 20-year heat exchanger limited warranty
- Cabinet air leakage under 2.0% at 1.0 in. w.c. per ASHRAE 193
- AHRI certified; standard NOx configuration
WFER045A036C Cabinet & Airflow
- 14-3/16 in. cabinet width, the narrowest in the WFER line
- 12-9/16 in. supply outlet, 12-11/16 in. bottom inlet width
- 1/3 HP five-speed direct drive blower, 10 x 6 in. wheel
- 710 CFM heating, 1080 CFM cooling on as-shipped speed taps
- Certified external static pressure 0.10 heating / 0.50 cooling
- Four-position: upflow, downflow, horizontal-left, horizontal-right
- 4 in. vent connection, suitable for Type B-1 vent
- 40VA transformer with standard air conditioning blower relay
- 5.6 max amps, 7.8 ampacity, 15 amp maximum fuse or breaker
- 104 lb shipping weight — the lightest furnace in the series
Specifications & Manuals
The technical specifications sheet carries the nomenclature guide, physical data for size 045A036, the full air delivery table by speed tap and external static pressure, and the accessory part number list. The installation instructions cover clearances to combustibles, venting, gas piping and all four mounting positions.
Frequently Asked Questions
How many BTUs does the WFER045A036C actually deliver?
Input is 44,000 BTUH and output capacity is 36,000 BTUH at 80.00% AFUE, per DOE test procedures. The "45K" in the product name is the rounded nomenclature code, not the certified input figure.
What cabinet width does this furnace need?
14-3/16 in., with a 12-9/16 in. supply outlet and a 12-11/16 in. bottom return inlet. It is the narrowest cabinet in the WFER family, which is what makes it viable in tight utility closets.
What cooling capacity will the blower support?
Up to 3 tons. The 036 in the model number is the cooling size code, and the blower delivers 1080 CFM on the as-shipped cooling tap with a filter in place.
Can the WFER045A036C be installed in a downflow position?
Yes, it is a four-position furnace. Downflow installation is on non-combustible floors only, or on combustible flooring when a special base or coil assembly is used — accessory NAHA01101SB is the combustible floor base, and it is not required when an evaporator coil case is used.
Can this furnace run on propane?
Not as shipped. It is equipped for natural gas with a size 43 orifice. Accessory kit AGAGC8NPS01A converts it to propane; AGAGC8PNS01A converts back to natural gas. See the LP conversion kit selection.
What vent size does it require?
A 4 in. vent connection. It may be used with Type B-1 vent and may be common-vented with other gas-fired appliances. A chimney adapter kit, NAHA00401DH, is available for exterior masonry chimney applications.
WFER Technical Specifications
