Suburban SF-35VHQ 35K BTU Ducted RV Furnace | Horizontal/Vertical

Heat your mid-size or large RV with confidence with the Suburban SF-35VHQ 35,000 BTU Ducted Horizontal/Vertical RV Furnace. This commercial-grade Suburban furnace delivers maximum heating performance in a ducted configuration — engineered for the design flexibility of either horizontal OR vertical installation, making it easy to fit into spaces that might otherwise go unused. The right replacement for owners of older Suburban SF/SF-Q series furnaces, or for buyers upgrading from Dometic DFMD or Atwood AFMD furnaces (with important fitment caveats noted below).

Maximum Heating Performance for Mid-Size and Large RVs

The SF-35VHQ delivers 35,000 BTU/h input — substantial heating capacity for cold-weather camping, winter use, and larger floor plans:

• 35,000 BTU/h input — handles mid-size to large RV heating loads
• Ducted configuration — distributes heat throughout the RV via the duct network rather than concentrating it in one area
• Increased design flexibility from the dual-orientation mounting
• Proven Suburban Q-series architecture — established reliability platform

Horizontal OR Vertical Installation Flexibility

One of the standout features of the SF-Q series: it can be installed in either horizontal OR vertical orientation. That dual-mount flexibility means:

• Fits in tight spaces that wouldn't accommodate a fixed-orientation furnace
• Lets you utilize otherwise dead space in cabinetry or compartments
• Adapts to your RV's layout rather than forcing layout compromises
• Simplifies replacement in RVs where the original furnace location is awkward

Replaces a Wide Range of Suburban Furnaces

The SF-35VHQ is the direct replacement for many older Suburban SF-Series furnaces:

• SF35, SF-35Q, SF-35QHT
• SF25, SF25Q, SF25QHT
• SF30, SF-30Q, SF30QHT

If your existing furnace shows any of these part numbers, this SF-35VHQ is a compatible Suburban-to-Suburban replacement. Even though some of these older models had lower BTU ratings (25K, 30K), the SF-35VHQ at 35K BTU provides upgraded heating capacity in the same fitment footprint.

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

The SF-35VHQ can also replace Dometic DFMD and Atwood AFMD furnaces (also known as Atwood/Dometic HydroFlame 35K BTU furnaces), but with two critical fitment differences you must accommodate:

• Width difference: Dometic/Atwood furnaces are 1" WIDER than Suburban units. The SF-35VHQ is 1" narrower in width than your existing Dometic/Atwood furnace — this gap will need to be accommodated in the installation.
• Gas line side: Dometic/Atwood furnaces have the gas line on the LEFT side. Suburban furnaces (including this SF-35VHQ) have the gas line on the RIGHT side. The gas line will need to be re-routed or the connection adapted.

These differences are NOT showstoppers — many buyers successfully convert from Dometic/Atwood to Suburban furnaces — but they 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 before ordering.

LP Propane Fuel

The SF-35VHQ runs on LP (propane) — the standard fuel for RV furnaces, available at any campground or filling station.

Ducting Requirements

The SF-35VHQ's ducted design requires proper supply and return air configuration for optimal performance:

• Supply ducts: 4 × 4" diameter ducts required
• Return air: 55 sq inches of return air opening required

Ensure your RV's duct system meets these specifications, or plan for adjustments during installation. Insufficient ducting or return air can cause performance issues and premature wear.

Electrical Specifications

• Voltage: 12V DC
• Amp Draw: 8 amps
• Compatible with standard RV 12V electrical systems

Physical Specifications

• Dimensions: 7.5" × 17" × 20"
• Weight: 29 lbs

What's Included

• (1) Suburban SF-35VHQ furnace
• Vents
• Mounting screws
• Installation manual

⚠️ Packaging Note — No Original Manufacturer Box

These furnaces are new units but they do NOT come in the original Suburban manufacturer box. They are carefully double-boxed for shipping to prevent transit damage. This packaging approach has proven more effective at preventing damage during freight transit than the original manufacturer packaging.

⚠️ Minor Edge Bends Acceptable

Because the cage is constructed of aluminum (which is pliable by design), you may notice minor bends or imperfections on the edges of the cage. These cosmetic details:

• Do NOT affect performance or fitment of the furnace
• Are normal for this material and design
• Can be gently straightened by hand if cosmetic appearance matters in your installation

The functional cage rigidity and the furnace's mounting interfaces are unaffected. These edge cosmetics are not a quality issue — just the reality of working with a pliable aluminum cage.

2-Year Manufacturer Warranty

The SF-35VHQ is backed by Suburban's 2-year manufacturer warranty — meaningful protection for one of the most critical components of cold-weather RV travel.

⚠️ 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 with experience working on Suburban furnaces. 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 when relevant:

• Igniter electrodes: Suburban 525009 (broad SF/SFV/SH/SHD compatibility) or 525051 (SF/SFV Q and FQ specific) — common service items in furnace troubleshooting
• Furnace motors: Suburban 521255 (SF-35VHQ/VHFQ post-2001 motor) — the motor specifically engineered for this SF-35VHQ furnace family

Genuine Suburban OEM

As a Suburban factory unit, the SF-35VHQ is built to current OEM specifications for RV furnace installations.

Key Features

• Genuine Suburban SF-35VHQ 35,000 BTU ducted RV furnace
• Horizontal OR vertical installation — design flexibility
• 35,000 BTU/h input — for mid-size and large RVs
• LP propane fuel
• 12V DC, 8 amp draw
• 4 × 4" duct supply requirement
• 55 sq in return air requirement
• Replaces Suburban: SF35, SF-35Q, SF-35QHT, SF25, SF25Q, SF25QHT, SF30, SF-30Q, SF30QHT
• Replaces Dometic DFMD and Atwood AFMD (HydroFlame) with fitment caveats (1" width difference, gas line side opposite)
• Includes vents, mounting screws, and installation manual
• New unit — not refurbished, but ships without original manufacturer box (double-boxed for damage prevention)
• Minor edge bends on aluminum cage are normal and cosmetic only
• Dimensions: 7.5" × 17" × 20"
• Weight: 29 lbs
• Backed by 2-year manufacturer warranty

Specifications

• Brand: Suburban
• Model: SF-35VHQ
• Type: Ducted RV Furnace
• Heating Input: 35,000 BTU/h
• Fuel: LP (Propane)
• Installation Orientation: Horizontal OR Vertical
• Voltage: 12V DC
• Amp Draw: 8 A
• Supply Ducts: 4 × 4" required
• Return Air: 55 sq inches required
• Dimensions: 7.5" × 17" × 20"
• Weight: 29 lbs
• Replaces (Suburban): SF35, SF-35Q, SF-35QHT, SF25, SF25Q, SF25QHT, SF30, SF-30Q, SF30QHT
• Replaces (Dometic/Atwood): DFMD, AFMD (HydroFlame 35K BTU furnaces) — with fitment caveats (1" width difference, opposite gas line side)
• Condition: New (not in original manufacturer box; double-boxed for shipping)
• Includes: Furnace, vents, mounting screws, installation manual
• Warranty: 2-year manufacturer warranty