Suburban SF-25FQ 25K BTU Ducted RV Furnace | Front Gas Connect

Heat your mid-size RV efficiently with the Suburban SF-25FQ 25,000 BTU Ducted RV Furnace (References 2390A / 2555). This Suburban SF-FQ series furnace delivers proportional heating capacity for mid-size floor plans with the design flexibility of Suburban's proven ducted architecture. The right replacement for a wide range of older Suburban SF and NT Series furnaces at the 20K–25K BTU capacity range, or an upgrade path for owners of legacy Dometic DFMD and Atwood AFMD furnaces at the same BTU class.

⚠️ FQ Variant — Gas Connects at the FRONT

Important fitment detail: the SF-25FQ is the FQ variant — meaning the gas line connects at the FRONT of the unit. If your existing furnace has the gas line connecting at the rear or side, plan for gas line re-routing during installation. Verify your installation can accommodate front-side gas connection before ordering.

25,000 BTU Heating for Mid-Size RVs

The SF-25FQ delivers proportional heating for typical mid-size RV applications:

• BTU Input: 25,000 BTU/hr
• Sized for mid-size RVs — right-sized to avoid short-cycling in smaller floor plans while providing adequate heat for typical travel trailer and motorhome sizes
• Ducted configuration — distributes heat throughout the RV via the duct network

LP Propane Fuel

Runs on LP (propane) — standard RV furnace fuel.

Ducting Requirements

• Supply ducts: 3 × 4" diameter
• Return air: 55 sq inches

Electrical Specifications

• Voltage: 12V DC
• Amp Draw: 7 amps

Wide Suburban Replacement Compatibility

The SF-25FQ is a direct replacement for many older Suburban furnaces at the 20K–25K BTU range:

Suburban SF Series (SF-25 range)

• SF-25FQ, SF25, SF25Q, SF-25VHQ, SF-25VHFQ, SF-25VHQT, SF-25HQT

Suburban SF Series (SF-20 range)

• SF-20FQ, SF-20Q, SF-20VHQ, SF-20VHFQ, SF-20VHQT, SF20

Suburban NT Series

• NT-20SEQ, NT-16SEQ, NT-20SQ, NT-16SQ

If your existing furnace shows any of these part numbers, this SF-25FQ is a compatible Suburban replacement.

⚠️ Replacing a Dometic DFMD or Atwood AFMD? Read This First

The SF-25FQ can also replace Dometic DFMD and Atwood AFMD 25K BTU furnaces (also known as Atwood/Dometic HydroFlame 25K BTU furnaces), but with two critical fitment differences you must accommodate:

• Width difference: Dometic/Atwood furnaces are 1" WIDER than Suburban units. The SF-25FQ is 1" narrower — this gap will need to be accommodated during installation.
• Gas line side: Dometic/Atwood furnaces have the gas line on the LEFT side. Suburban furnaces (including this SF-25FQ) have the gas line at the FRONT (per the FQ designation). Gas line will need re-routing.

These differences are not showstoppers, but require planning and proper installation. Confirm with your installer that both the width gap and gas line re-routing can be accommodated in your specific installation.

What's Included

• (1) Suburban SF-25FQ furnace
• Vents
• Mounting screw
• Installation manual

⚠️ Packaging Note — No Original Manufacturer Box

These furnaces are new units but do NOT come in the original Suburban manufacturer box. They are carefully double-boxed by us for shipping to prevent transit damage.

⚠️ Minor Edge Bends Acceptable

The aluminum cage is pliable by design — you may notice minor bends on the edges of the cage. This does NOT affect performance or fitment and can be gently straightened by hand if cosmetic appearance matters. Functional cage rigidity and mounting interfaces are unaffected.

1-Year RV Surplus Parts Warranty

Backed by our 1-year parts warranty.

⚠️ Professional Installation Required

RV furnace installation involves working with the RV's propane gas system, 12V DC electrical, duct integration, and structural mounting. Improperly installed propane appliances are a fire and explosion risk. Installation should be performed by a qualified RV service technician. Always perform proper leak testing on gas connections after installation.

Pairs with Suburban Furnace Repair Parts

If you're servicing or restoring a Suburban furnace, consider these related repair parts:

• Igniter electrodes: Suburban 525009 (broad SF/SFV/SH/SHD compatibility) or 525051 (SF/SFV Q and FQ specific — matches this FQ furnace family)

Key Features

• Genuine Suburban SF-25FQ 25,000 BTU ducted RV furnace
• FQ variant — gas connects at the FRONT of the unit
• 25,000 BTU/hr input — right-sized for mid-size RVs
• LP propane fuel
• 12V DC, 7 amp draw
• 3 × 4" duct supply requirement
• 55 sq in return air requirement
• Wide Suburban replacement compatibility: SF-25 series, SF-20 series, NT-20SEQ/16SEQ/20SQ/16SQ
• Also replaces Dometic DFMD / Atwood AFMD 25K BTU with fitment caveats (1" width difference, opposite gas line configuration)
• Includes vents, mounting screw, and installation manual
• New unit — double-boxed for shipping (no original manufacturer box)
• Minor edge bends on aluminum cage are normal and cosmetic only
• Dimensions: 7.5" × 17" × 20"
• Weight: 29 lbs
• Backed by 1-year RV Surplus parts warranty

Specifications

• Brand: Suburban
• Model: SF-25FQ
• Cross-Reference Numbers: 2390A, 2555
• Type: Ducted RV Furnace
• Heating Input: 25,000 BTU/hr
• Fuel: LP (Propane)
• Gas Connection Location: Front (FQ variant)
• Voltage: 12V DC
• Amp Draw: 7 A
• Supply Ducts: 3 × 4" required
• Return Air: 55 sq inches required
• Dimensions: 7.5" × 17" × 20"
• Weight: 29 lbs
• Replaces (Suburban SF): SF-25FQ, SF25, SF25Q, SF-25VHQ, SF-25VHFQ, SF-25VHQT, SF-25HQT, SF-20FQ, SF-20Q, SF-20VHQ, SF-20VHFQ, SF-20VHQT, SF20
• Replaces (Suburban NT): NT-20SEQ, NT-16SEQ, NT-20SQ, NT-16SQ
• Replaces (Dometic/Atwood): DFMD, AFMD (HydroFlame 25K BTU) — with fitment caveats
• Condition: New (not in original manufacturer box; double-boxed for shipping)
• Includes: Furnace, vents, mounting screw, installation manual
• Warranty: 1-year RV Surplus parts warranty