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Quick specs
Brand
Rheem
BTU Input
100,000 BTU/h
BTU Output
80,000 BTU/h
AFUE
80%
Heating Stages
Single-Stage
Blower Motor
3/4 HP 5-Speed Constant Torque ECM
Cabinet Width
21"
Airflow Configuration
Upflow/Horizontal
Max Cooling Airflow
1,840 CFM
Not sure this fits your unit?
Call us with your model number and we'll confirm the right part before you order.
Rheem Endeavor Line 80% AFUE 100,000 BTU Single-Stage Upflow/Horizontal Gas Furnace R801T1005A21UHSNAS
Rheem Endeavor Line Classic Series·80% AFUE Single-Stage
$2,090.49
-
- Free shipping — most items ship by the next day
Licensed HVAC technician required. Must be installed by a certified professional. Improper installation voids the manufacturer warranty.
Secure payment
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Rheem Endeavor Line 80% AFUE 100,000 BTU Single-Stage Upflow/Horizontal Gas Furnace R801T1005A21UHSNAS
Licensed HVAC technician required. Must be installed by a certified professional. Improper installation voids the manufacturer warranty.
Need help? (888) 292-0874
- Free shipping — most items ship by the next day
Secure payment
VISA MC AMEX DISC PayPal Affirm CHECK
In stock
In most items, small items ship same day. Complete systems ship next business day.
$2,090.49
-
Need help? (888) 292-0874
- Free shipping — most items ship by the next day
Secure payment
VISA MC AMEX DISC PayPal Affirm CHECK
Quick specs
Brand
Rheem
BTU Input
100,000 BTU/h
BTU Output
80,000 BTU/h
AFUE
80%
Heating Stages
Single-Stage
Blower Motor
3/4 HP 5-Speed Constant Torque ECM
Cabinet Width
21"
Airflow Configuration
Upflow/Horizontal
Max Cooling Airflow
1,840 CFM
Not sure this fits your unit?
Call us with your model number and we'll confirm the right part before you order.
This Rheem Endeavor Line Classic Series 80% AFUE Single-Stage Gas Furnace R801T1005A21UHSNAS is a solid, value-oriented choice for residential replacements or new installations needing a reliable 100k BTU upflow/horizontal furnace with modern diagnostic features and a compact footprint.
- Rheem Endeavor Line Classic Series
- 80% AFUE efficiency – Delivers reliable heating while helping keep operating costs reasonable for a standard-efficiency furnace.
- Single-stage heating – Simple, dependable operation with lower installation and service complexity.
- Constant Torque ECM blower motor – Provides consistent airflow, better efficiency than a standard PSC motor, and improved comfort and humidity control when paired with air conditioning.
- PlusOne® Diagnostics – Industry-first 7-segment LED display for fast, accurate troubleshooting and reduced service time.
- PlusOne® Ignition System – Proven Direct Spark Ignition (DSI) for reliable starts and long service life.
- Low-profile 34″ cabinet – Ideal for space-constrained installations (closets, attics, crawl spaces, etc.).
- Upflow/Horizontal multipoise design – Flexible installation options to fit a wide range of home layouts.
- Removable aluminized steel primary heat exchanger – Excellent corrosion resistance and thermal durability; removable design improves serviceability.
- Hemmed cabinet & door edges + quarter-turn fasteners – Tool-less access for safer, faster maintenance.
- Insulated blower compartment & solid bottom – Quieter operation and cleaner installation.
- Built-in connections – Humidifier, electronic air cleaner, and twinning provisions for system expandability.
- Natural gas ready (LP convertible) – Field-convertible to propane with the appropriate kit.
- 21″ cabinet width – Supports higher airflow capacity for up to 5-ton cooling (≈1,840 CFM).
- Input: 100,000 BTU/h
- Output: 80,000 BTU/h
- AFUE: 80%
- Configuration: Upflow / Horizontal
- Cooling capacity: Up to 5 tons
- Blower motor: ¾ HP 5-speed Constant Torque ECM
- Cabinet dimensions: 21″ W × 29.59″ D × 34″ H
- Weight: approx. 140 lbs
- Voltage: 115 V / 60 Hz / 1-phase
- Width: 21 in
- Depth: 29.59 in
- Height: 34 in
Key features
- Rheem Endeavor Line Classic Series — value-oriented, reliable gas heat
- 80% AFUE Single-Stage — dependable residential heating
- Modern Diagnostics — simplifies service and troubleshooting
- Compact Footprint — upflow/horizontal installation
Why homeowners choose NAW
Genuine OEM parts
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30-day hassle-free returns
Ordered the wrong part? Send it back within 30 days.
Help when you need it
Not sure if this is the right part? Call us at (888) 292-0874 and we’ll help you find the correct replacement.
Customer reviews
What buyers are saying
Verified reviews from customers who purchased this product.
5.0
8 verified reviews
BF
Billy F
The Rheem 80% AFUE 100,000 BTU Single Stage Upflow/Horizontal Gas Furnace 21″ Wide delivered far more power and efficiency than I expected at such an excellent price. The equipment runs flawlessly and keeps the whole house warm with impressive consistency and reliability.
FD
Felix D
I was truly impressed by the powerful heating and efficiency of this Rheem 80% AFUE 100,000 BTU Single Stage Upflow/Horizontal Gas Furnace, keeping my home warm and comfortable while reducing energy costs. With outstanding quality at an unbeatable price, this furnace is a perfect choice for reliability, performance, and long-term savings.
IP
Ivan P
I’m amazed by the Rheem 80% AFUE 100,000 BTU Single Stage Upflow/Horizontal Gas Furnace! With an unbeatable price for such high-quality equipment, it provides powerful and efficient heating that keeps my home warm and cozy no matter the temperature outside!
TG
Terry G
The Rheem 80% AFUE 100,000 BTU Gas Furnace, with its versatile 21-inch width, delivered powerful and consistent heating that quickly made our home a cozy haven even in freezing weather! Given its impressive performance and robust build, the price was remarkably low, making this furnace a fantastic investment for anyone seeking quality heating without overspending.
AH
Angelo H
I recently purchased the Rheem 80% AFUE 100,000 BTU Single Stage Upflow/Horizontal Gas Furnace 21″ Wide, and I’m absolutely thrilled with the incredible price, top-notch equipment, and exceptional performance that have made a significant difference in my home comfort!
R
Rico
I’m absolutely thrilled with the Rheem 80% AFUE 100,000 BTU Gas Furnace – the price is remarkably competitive for the exceptional equipment and performance it delivers. The single-stage design and generous 21″ width make it a standout choice, combining efficiency and affordability in a way that exceeded my expectations!
C
Charlie
Hold onto your hats, because the Rheem 80% AFUE 100,000 BTU Single Stage Upflow/Horizontal Gas Furnace is a game-changer! The unbelievable price, combined with its generous warmth and stellar performance, has turned my chilly home into a toasty paradise – a fantastic deal for anyone seeking affordable luxury in heating.
G
Greg
Compact powerhouse at an unbeatable value! The Rheem 80% AFUE 100,000 BTU Single Stage Upflow/Horizontal Gas Furnace, at just 21″ wide, astounds with its remarkable heating capabilities and top-quality equipment, all at a surprisingly competitive price. Its single-stage operation ensures reliable and efficient heating, making it an exceptional choice for optimal comfort without breaking the bank.
