Suburban SF-25Q 25K BTU Ducted RV Furnace | Back Gas | LP

Heat your mid-size RV with the Suburban SF-25Q 25,000 BTU Ducted Furnace (Reference 2556A). Suburban's proven SF-Q series ducted furnace — the Q variant with gas connecting at the back of the unit.

⚠️ You May Receive an SF-25VHQ Instead

The SF-25Q is no longer in current production — Suburban replaced it with the SF-25VHQ (horizontal/vertical variant). Our supplier likely has limited SF-25Q inventory remaining, so you may receive an SF-25VHQ instead. Both furnaces are fully interchangeable at the same 25K BTU rating — same fitment, same replacement compatibility. If you receive an SF-25VHQ, it's the modern successor and installs identically.

⚠️ Q Variant — Gas Connects at the BACK

Gas line connects at the BACK of the unit (distinct from FQ variants where gas connects at the front). If you receive the SF-25VHQ successor, gas connection is horizontal/vertical flexible.

25,000 BTU Heating for Mid-Size RVs

• BTU Input: 25,000 BTU/hr
• Ducted configuration
• LP propane fuel

Ducting Requirements

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

Electrical

• Voltage: 12V DC
• Amp Draw: 7 amps

Wide Suburban Replacement Compatibility

• SF25, SF25Q, SF20, SF-20Q

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

The SF-25Q can also replace Dometic DFMD and Atwood AFMD 25K BTU furnaces, with two critical fitment differences:

• Width difference: Dometic/Atwood furnaces are 1" WIDER than Suburban. Plan for the 1" gap.
• Gas line side: Dometic/Atwood have gas on the LEFT side; this Suburban connects at the BACK. Gas line will need re-routing.

What's Included

• (1) Suburban SF-25Q furnace (or SF-25VHQ successor)
• Vents
• Mounting screws
• Installation manual
• Original manufacturer box

2-Year Suburban Manufacturer Warranty

⚠️ Professional Installation Required

RV furnace installation involves working with propane gas, 12V DC electrical, ducting, and structural mounting. Installation should be performed by a qualified RV service technician. Always leak-test gas connections after installation.

Pairs with Suburban SF Series Repair Parts

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

• Igniter electrodes: Suburban 525009 (broad SF/SFV compatibility) or 525051 (SF/SFV Q and FQ specific)

Key Features

• Genuine Suburban SF-25Q 25,000 BTU ducted furnace
• Q variant — gas connects at back
• SF-25VHQ (successor) may be substituted — fully interchangeable
• 25,000 BTU/hr input for mid-size RVs
• LP propane fuel
• 12V DC, 7 amp draw
• 3 × 4" duct supply, 55 sq in return
• Replaces: SF25, SF25Q, SF20, SF-20Q; Dometic DFMD, Atwood AFMD (25K BTU) with fitment caveats
• Includes: Vents, mounting screws, manual, in original manufacturer box
• Dimensions: 7.5" × 17" × 20"
• Weight: 29 lbs
• Backed by 2-year Suburban manufacturer warranty

Specifications

• Brand: Suburban
• Model: SF-25Q (SF-25VHQ successor may substitute)
• Cross-Reference: 2556A
• Type: Ducted RV Furnace
• Heating Input: 25,000 BTU/hr
• Fuel: LP (Propane)
• Gas Connection Location: Back (Q 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): SF25, SF25Q, SF20, SF-20Q
• Replaces (Dometic/Atwood): DFMD, AFMD (25K BTU) — with fitment caveats
• Includes: Furnace, vents, mounting screws, manual, in original manufacturer box
• Modern Successor: SF-25VHQ (fully interchangeable, may substitute)
• Warranty: 2-year Suburban manufacturer warranty