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— answers from the official manualAnswers from the official manual.
Common questions
Common Questions
10 totalWhat should I do if my Thermo Pride furnace is showing an error code?
Refer to the manual’s error code list for specific troubleshooting steps. Each error code will provide guidance on how to correct or address the issue (Page 14).
How can I increase the efficiency of my Thermo Pride furnace?
Using high-efficiency Beckett or optional Riello burners improves combustion and fuel efficiency in your furnace (Page 5). Ensure regular servicing to maintain optimal performance.
What type of air filter should I use with my Thermo Pride furnace?
Thermo Pride recommends a washable air filter which can be cleaned and reused, providing convenience and cost savings over disposable filters (Page 6).
How do I access the maintenance ports on my Thermo Pride furnace?
Access to the inspection ports is easy due to their large size. Locate them for routine check-ups and cleaning as instructed by your manual (Page 3).
Can I switch from oil fuel to natural gas or propane on my Thermo Pride furnace?
Yes, all Thermo Pride octagon-shaped oil furnaces can be easily changed from oil to either natural gas or propane (L.P) gas. Refer to your manual for specific burner recommendations and installation guidelines.
What dimensions and weights do lowboy furnaces have?
Lowboy furnace models range in dimensions from 19 x 48 x 34.75 inches to 27 x 58.5 x 50.5 inches, with approximate shipping weights varying between 315 lbs and 600 lbs (Page 5).
Full Manual
6 pages

Thermo Pride Oil Heating At Its Best
Built Tough for Lifetime Comfort™

Oil Heating At Its Best
Thermo Pride Dependable Craftmanship
For the past 60 years, Thermo Pride has listened to your concerns about comfort and has met your demands for the best, most reliable, and efficient furnaces and cooling systems. Every Thermo Pride product is built with traditional, dependable craftsmanship. What this means to you is quiet, reliable, long lasting performance.

Comfort Comfort is the purpose behind any heating system. “Temperature rise” makes the difference between feeling warm, comfortable air from the registers in your home or the feeling of cool air blowing across you when the furnace is on. It is the difference in air temperature from the point where it enters the furnace to the point where it exits. The higher the temperature rise—the warmer the air when it enters the rooms of your home. Thermo Pride has a standard 70°F temperature rise across its full line of oil furnaces. This is an air temperature up to 30°F warmer than the competition—providing a far superior comfort level.
Temperature Rise
Handcrafted Quality Each Thermo Pride cabinet is powder coated inside and out for a durable, tough finish that will ensure long life and a quality appearance. The interlocking insulated furniture grade steel cabinet helps retain heat within the furnace and prevents annoying vibrations during operation. The rounded corners add structural strength and a pleasing appearance to the cabinet.
The heat exchanger is fabricated of 13-gauge copper coated steel in a unique octagonal shape to increase the surface area and the heat transfer of the heat exchanger. The copper coating helps prevent corrosion from external damp conditions. This unique combination of design and material provides Thermo Pride oil furnace owners with the confidence that these furnaces are made to last a lifetime!
Warranty The proven longevity of Thermo Pride’s heat exchanger, combined with the Limited Lifetime Warranty, virtually eliminates the worry of ever having to replace your furnace. Should you sell your home, the warranty will automatically transfer to the new owners. Thermo Pride furnaces also come with a “Peace of Mind” 5-year parts warranty. An optional 5-year labor coverage is also available, or you have the opportunity to extend this warranty to a 10-year parts and labor warranty.
Thermo Pride’s manufacturing facilities have earned the prestigious ISO 9001:2000 certification. This seal assures consistent quality products through a structured quality control process. Thermo Pride oil products have also earned the industry-respected certification for safety from Underwriter’s Laboratory (UL).
Features and Benefits

Honeywell Automatic/Manual Fan & Limit Control
Front or Rear Flue Option
13-gauge Copper Powder Coated Octatherm Heat Exchanger
Chrome Plated Handles
Large, Easily Accessable Inspection Ports
Filter Frame and Filter
4-Speed Direct Drive Blower Motor (shown)
22-gauge Furniture Grade Steel Cabinet Construction
or Belt Driven Motor
Ceramic Refractory Heavy Fiber Chamber
High Efficiency Flame Retention Beckett Burner
Sound and Vibration Absorbing Blower Mounts
Optional Riello Burner







Blower Motors Thermo Pride’s direct-drive blowers allow the installer to select the appropriate heating and cooling blower speed for your home. A belt drive blower motor is available for heating only applications.

Ceramic Refractory The ceramic refractory is designed to assure more complete combustion which means increased efficiency. It also provides protection for the heat exchanger from the direct flame and ensures quiet operation. (not available on the , 33, 37 and 39 units.)
Heavy Fiber Chamber Thermo Pride provides a heavier, thicker fiber chamber than most of its competitors. These are standard in the , 33, 37 and 39 units.
Honeywell Automatic/Manual Fan & Limit Control This control starts and stops the blower fan at the appropriate temperatures to ensure that only warm comfortable air enters your home. The manual feature allows for consistent air movement.
Filter Frame and Filter A washable air filter means cleanliness, convenience, and cost savings over disposable air filters.
High-efficiency Flame Retention Burner Beckett hi-speed flame retention burners are standard on Thermo Pride furnaces. They provide more complete combustion and higher fuel efficiency. Optional Riello Burner

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Built Tough for Lifetime Comfort™
Thermo Pride offers you a full line of oil furnaces. From the traditional highboy, lowboy, counterflow and horizontal units, as well as the low-profile highboy and variable speed ECM motor furnaces, to the -stage oil unit and the mobile home furnace you’re sure to find one that’s perfect for your home.
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Built with Your Home in Mind Cabinet Construction Thermo Pride cabinet panels are fabricated of gauge cold-rolled steel with rounded corners and an interlocking design for a more finished appearance and greater strength. The cabinet is powder coated on both sides and is lined with ½” thick reinforced fiberglass insulation for maximum heat retention. On all basement, upflow and downflow furnaces, Thermo Pride incorporates a burner vestibule enclosure into its design. The vestibule and insulation diminish burner combustion noise and provide safety by isolating controls from children and pets. Octatherm™ Heat Exchanger At the heart of every Thermo Pride oil-fired furnace is the “Octatherm” heat exchanger. The heat
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exchanger is fabricated out of 13-gauge copper coated steel. Some manufacturers use less expensive, thinner 14 or 16-gauge steel. Thermo Pride’s copper powder coating helps prevent corrosion from
damp conditions often encountered in basement installations.
Thermo Pride further stands out by individually sizing its heat exchangers for virtually every model furnace offered. This helps to assure maximum efficiency, longest life, and the highest comfort for all applications.
The octatherm heat exchanger’s unique eight sided design provides more efficient use of the heat transfer area. This design puts less stress on the steel and thus provides a longer life. As a result, the octatherm design generates increased dependability and a lifetime of comfort for your home.
Perfect Application Thermo Pride oil furnaces provide complete product flexibility. Available in BTU per hour output rages from 56,000 to 30,000 to comfortably heat any size home, Thermo Pride oil furnaces offer the widest selection available—there’s one that’s right for your home.

Choose from four different configurations.
. Highboys (OH) are perfect for basements, utility rooms and closets. They feature a top flue discharge and vestibule enclosed burners.
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Specifications
WARM AIR OUTLET (IN INCHES) W x L
RETURN AIR INLET (IN INCHES) W x L
MAXIMUM A/C CAPACITY
BTU/H OUTPUT at BONNET 3
DIMENSIONS (IN INCHES) W x L x H
APPROX. SHIPPING WEIGHT
STANDARD BD DD
UPGRADE BD DD
MODEL NUMBER AFUE%1
|LOWBOY|OL2-56|82.8|56,000|19 x 48 x 34¾|17 x 17|17 x 17|—|3|—|—|315| |---|---|---|---|---|---|---|---|---|---|---|---| |LOWBOY|OL5-85|82.0 / 86.0 2|85,000|25 x 50¼ x 43¼|20 x 20|20 x 14|2|3.5|4|4|410| |LOWBOY|OL11-105|81.6 / 82.6 2|101,000|25 x 54½ x 46½|20 x 20|20 x 16|2|3.5|4|4|500| |LOWBOY|OL16-125|80.0|125,000|25 x 58½ x 46½|22 x 22|22 x 18|3.5|5|5|—|560| |LOWBOY|OL20-151|81.1|151,000|27 x 58½ x 50½|22 x 22|22 x 18|—|5|—|—|600| |LOWBOY|OL33-200|— 5|200,000|34 x 72 x 60¾|28 x 28|28 x 24|5|—|10|—|1025| |LOWBOY|OL37-250|— 5|250,000|38 x 85½ x 67¾|32 x 32|32 x 28|5|—|10|—|1120| |LOWBOY|OL39-320|— 5|320,000|38 x 85½ x 67¾|32 x 32|32 x 28|8|—|10|—|1150| |HIGHBOY|OH2-56|80.7|56,000|19 x 27 x 52|17 x 17|20 x 16|—|3|—|—|300| |HIGHBOY|OH5-85|80.6 / 86.0 2|85,000|24 x 33 x 56|22 x 20|25 x 16|—|3.5|—|4|410| |HIGHBOY|OH11-105|80.0 / 85.0 2|101,000|24 x 34 x 59½|22 x 20|25 x 16|—|3.5|—|4|490| |HIGHBOY|OH16-125|80.0|125,000|27 x 36½ x 66|22 x 22|25 x 16|—|5|—|—|546| |HORIZONTAL
COUNTERFLOW|OC2-56|81.0|56,000|19 x 27 x 57½|17 x 17|17 x 17|—|2.5|—|—|305| |HORIZONTAL
COUNTERFLOW|OC5-85|83.3|85,000|24 x 33 x 56|20 x 16|22 x 20|—|3|—|3.5|420| |HORIZONTAL
COUNTERFLOW|OT5-85 4|82.1|85,000|24½ x 68 x 20½|18 x 16|18 x 16|—|3.5|—|—|365| |HORIZONTAL
COUNTERFLOW|OT11-105 4|78.2|101,000|24½ x 74 x 24|20 x 20|20 x 20|—|3.5|—|4|445| |HORIZONTAL
COUNTERFLOW|OT16-125 4|78.0|125,000|26 x 74 x 26|22 x 20|22 x 20|—|5|—|—|500|
Accessories Thermo Pride offers a complete line of heating/cooling equipment. The addition of accessories to your system can provide greater comfort and a healthier indoor environment.
UV Aire
Improve the indoor air quality of your home by adding a UV Aire-Air Purifying System to your home heating and cooling ductwork. UV Aire silently and effectively reduces

airborne contaminates including molds, bacteria, yeasts, dust mites, and viruses that can cause allergies.
Premiere Series Programmable Thermostat Perfect for a combination heating/ cooling system, the Premiere Series Programmable Thermostat maximizes

comfort while saving energy. Use up to four different timed programs to save energy.
Electronic Air Cleaner and Media Air Filter
Air cleaners and media filters remove odors and up to 99% of air born pollutants, plus keep the dust under control.

Power Humidifier Proper humidity levels in your home increases comfort, reduce annoying static electricity, dried cracked furniture and wood trim, and wilting houseplants.

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Form No. PL81410021000-2/06-30Ms
Printed in the U.S.A. © 2006 Thermo Products, LLC - North Judson, IN
Phone: 574-896-2133 www.thermopride.com