Atwood Hydro Flame RV Furnace Blower Motor | 37697 30133 12V 2250 RPM Replacement

Atwood Hydro Flame RV Furnace Blower Motor – 37697 30133 12V 2250 RPM Replacement

The furnace blower motor is the component that circulates air through your RV furnace’s heat exchanger and into the living space. It draws in cool air from the RV interior, pushes it through the heated heat exchanger, and distributes warm air through the ductwork. A failing blower motor can cause weak or no airflow, overheating of the heat exchanger, strange noises, or complete furnace failure.

This Atwood Hydro Flame RV furnace blower motor is a direct replacement for Atwood part numbers 37697 and 30133. It features a 12V DC motor running at 2250 RPM with a double shaft design, compatible with the standard squirrel cage blower wheels used in Atwood Hydro Flame furnaces.

Compatibility

• Atwood Hydro Flame 85-IV series: 8516-IV, 8520-IV, 8525-IV, 8531-IV, 8535-IV
• Atwood Hydro Flame 89-III series: 8916-III, 8920-III, 8925-III, 8930-III, 8935-III
• Atwood AFMD series: AFMD20111, AFMD25111, AFMD30111, AFMD35111
• Atwood 7900-II series: 7912-II, 7916-II, 7920-II, 7924-II, 7932-II
• Dometic DFMD series (rebranded Atwood): DFMD20121, DFMD25121, DFMD30121, DFMD35121
• Replaces part numbers: 37697, 30133, 33488, 31501 (motor assembly)
• Most 16,000-35,000 BTU Atwood/Dometic Hydro Flame furnaces

Specifications

Installation Guide

1. Safety first: Disconnect 12V power at the battery. Turn off propane supply. Allow the furnace to cool completely if it was recently running.
2. Access the furnace: Remove the furnace exterior access panel. The blower motor is typically located at the rear of the furnace, visible through the access panel. You may need to remove the furnace from its mounting for easier access — consult your RV manual for furnace removal instructions.
3. Document connections: Take photos of the wiring and blower wheel positions before disconnecting. Note which wires go to which terminals.
4. Disconnect wiring: Unplug the wire connectors from the motor terminals. There are typically two wires (positive and negative — polarity doesn’t matter for this motor).
5. Remove blower wheels: The motor has a double shaft with a squirrel cage blower wheel on each end. Remove the set screw or clamp holding each wheel to the shaft. Gently slide the wheels off the shafts. Be careful not to bend the wheel fins.
6. Remove old motor: Unscrew the 2 mounting bolts holding the motor to the furnace housing. Carefully remove the motor from the furnace.
7. Install new motor: Insert the new 37697 motor into the mounting position. Secure with the 2 mounting bolts. Ensure the motor is properly aligned and seated.
8. Install blower wheels: Slide the squirrel cage blower wheels onto each shaft. Align the wheels so they don’t rub against the housing. Tighten the set screws or clamps. Spin the wheels by hand to verify they turn freely without rubbing.
9. Reconnect wiring: Plug the wire connectors onto the motor terminals. Ensure a secure connection.
10. Test operation: Reconnect 12V power. Turn on propane. Set the thermostat to call for heat. Verify:
    • The blower motor starts (you should hear air moving)
    • The blower wheels spin without rubbing or noise
    • Airflow is strong and consistent from the vents
    • The ignition sequence proceeds normally (pre-purge → spark → flame)
    • The furnace runs through a complete heating cycle without issues

    If the motor doesn’t start, check the wiring connections and 12V power. If the wheels rub, adjust their position on the shafts.

Common Symptoms of a Bad Blower Motor

• Weak or no airflow from the furnace vents
• Furnace ignites but shuts down quickly (overheat switch trips due to no airflow)
• Loud grinding, squealing, or rattling noises from the furnace
• Blower motor runs but slowly or intermittently
• Motor doesn’t start at all (no response to thermostat)
• Motor starts but stops after a few seconds
• Burning smell from the furnace (overheating motor)
• Blower wheel wobbles or vibrates excessively
• Furnace cycles on and off frequently (short cycling due to poor airflow)
• 12V fuse for the furnace blows repeatedly

Maintenance Tips

• Clean annually: Remove the blower wheels and clean them with a soft brush or compressed air to remove dust and debris buildup. This improves airflow and reduces motor strain.
• Lubricate bearings: Some blower motors have oil ports for bearing lubrication. If equipped, add 2-3 drops of lightweight machine oil (SAE 20) at the start of each heating season.
• Check wheel alignment: Ensure the blower wheels are properly aligned and not rubbing against the housing. Rubbing wheels cause noise, reduce airflow, and can damage the motor.
• Inspect wiring: Check the motor wiring for fraying, corrosion, or loose connections. Tighten or replace as needed.
• Test amperage: A properly functioning motor should draw 2.5-4.0A. If it draws more than 5A, the motor may be failing or the blower wheels may be restricted.
• Replace proactively: Blower motors typically last 8-12 years. If your motor is approaching this age or showing signs of wear, consider replacing it before it fails completely — a failed blower motor can cause the furnace overheat switch to trip, leaving you without heat.

Frequently Asked Questions

Q: How do I test if my blower motor is bad?

A: First, check if the motor is receiving 12V power when the thermostat calls for heat. Use a multimeter to measure voltage at the motor terminals. If 12V is present but the motor doesn’t run, the motor is likely bad. You can also test the motor directly by connecting it to a 12V battery (positive to one terminal, negative to the other). If it doesn’t spin or spins slowly, the motor is bad. If it spins fine when connected directly but not in the furnace, check the wiring, thermostat, and control board. Also check the blower wheels — if they’re restricted or rubbing, the motor may not be able to start.

Q: Can I replace just the motor or do I need the whole assembly?

A: This listing is for the motor only (without blower wheels). In most cases, you can reuse your existing squirrel cage blower wheels — simply remove them from the old motor and install them on the new motor. This is the most cost-effective repair option. However, if your blower wheels are damaged, bent, or heavily corroded, you may need to replace them as well. Some suppliers offer the complete motor + wheels assembly, but the motor-only replacement is standard and recommended.

Q: What’s the difference between 37697 and 30133?

A: 37697 and 30133 are essentially the same blower motor with different part numbers for different production runs or furnace models. The 37697 is the newer, more common part number that replaces the 30133. Both motors have the same specifications: 12V DC, 2250 RPM, double shaft, 1/8″ shaft diameter, 2-bolt mounting. The 37697 is fully backward-compatible with all furnaces that used the 30133. If your old motor has either part number, this replacement will work.

Q: Why is my furnace making a loud noise?

A: Loud noises from the furnace can have several causes: (1) Bad blower motor bearings — grinding or squealing noise that gets louder over time. The motor needs replacement. (2) Loose or damaged blower wheel — rattling or vibrating noise. Check the set screws and wheel condition. (3) Wheel rubbing housing — scraping noise. Adjust the wheel position on the shaft. (4) Debris in blower — clicking or rattling. Remove and clean the blower wheels. (5) Loose furnace mounting — vibrating or rattling. Tighten the furnace mounting bolts. If the noise is a high-pitched squeal or grinding, it’s most likely the blower motor bearings and the motor should be replaced.

Related Products

• 37357 RV Furnace Blower Motor — 12V double shaft furnace blower motor (alternative model)
• FAN 50 PLUS Ignitor Board — Universal 12V furnace ignitor board with fan control
• 31501 RV Furnace Ignition Board — Compatible with Atwood & Dometic Hydro Flame furnaces

Need help finding the right blower motor for your RV furnace? Contact our technical team with your furnace model number. Free shipping and duties included.