INSTAHEAT ULTRA
35K BTU RV Propane Furnace
$799.99
$1,299.99
Save $500.00
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$100 off with code Victory100
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Victory100
Four heat levels and a quieter mode for larger RVs.
InstaHeat 35K delivers up to 35,000 BTU through a central duct system, with 17K, 25K, 30K and 35K output levels. Rapid, Standard and Sleep modes, 260 CFM airflow and a 40 dB sleep setting give owners more control over recovery time and overnight comfort.
View all features ↓35,000 BTUMaximum propane heating output
4 heat levels17K, 25K, 30K and 35K
260 CFMAirflow for central RV ducting
40 dBSleep-mode operating sound
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30-day returns
Free local shipping
2-year warranty
At a glance
- 35,000 BTU maximum outputFour heating levels—17K, 25K, 30K and 35K—match different cabin demand.
- Rapid, Standard and Sleep modesChoose faster recovery, everyday temperature control or quieter overnight operation.
- 40 dB sleep modeReduces operating sound when overnight comfort matters most.
- 260 CFM airflowMoves heated air through a central RV duct system.
- Electronic wind-pressure sensorConfirms airflow before ignition without relying on a traditional sail switch.
- Horizontal or vertical mountingSupports different replacement layouts when the required bracket and clearances are used.
Fit and installation
- Furnace dimensions
- 17.7 W × 7.8 H × 20.1 D in
- Power supply
- 12V DC
- Duct outlet
- 4-in round
- Duct connections
- 7 openings
- Mounting
- Horizontal / vertical
- Heating system
- Central ducted
Confirm cabinet dimensions, return-air area, duct count, propane connection, exterior access and exhaust location. Non-horizontal installation requires the approved mounting bracket.
What’s included
- InstaHeat 35K RV propane furnace
- Smart wired controller
- Selected access-door configuration
- Installation and operation manual
- Package hardware shown for the selected variant
Vertical-mount brackets, ducting and propane-line materials should be confirmed separately for the installation.
Specifications
- Maximum heat output
- 35,000 BTU
- Heating levels
- 17K / 25K / 30K / 35K
- Operating modes
- Rapid / Standard / Sleep
- Airflow
- 260 CFM
- Sleep-mode sound
- 40 dB
- Electrical supply
- 12V DC
- Rated input
- 120W / 10A
- Duct static pressure
- 0.10 in WC
- Duct outlet size
- 4 in round
- Fuel
- LP propane
Common questions
Can it be installed vertically?
Yes, but any non-horizontal installation requires the approved mounting bracket and the clearances in the manual.
Will it work with in-floor ducts?
It is designed for central ducted RV heating and can work with compatible in-floor ducting when the static-pressure and airflow requirements are met.
What door should I choose?
Select No Door when reusing a compatible access arrangement, or choose the black or white door to match the installation plan.
Why use a wind-pressure sensor instead of a sail switch?
The electronic sensor verifies combustion airflow before ignition and is less dependent on a mechanical paddle exposed to dust and debris.
Recommended for your RV setup
Complete a larger RV comfort system with rooftop cooling and hot water selected for the installation. Confirm roof openings and water-heater door fit before ordering.
Add 18K cooling and 16K heat-pump output with ducted or non-ducted installation options. Confirm roof opening, roof thickness and 115V power.
Check roof fit and configuration
Add stable on-demand hot water with a built-in mixing tank. Confirm door dimensions, propane, 12V power, plumbing and venting before ordering.
Check door fit and installation
InstaHeat 35K
$100 off
·
$799.99
$1,299.99
Save $500.00
Reliable startup, adjustable output and quieter overnight heat.
The 35K furnace combines an electronic wind-pressure sensor, a proportional gas valve and four output levels. Each component has a specific job: verify airflow before ignition, meter fuel more precisely and avoid running maximum heat when the RV does not need it.
ELECTRONIC AIRFLOW SENSING
The furnace verifies airflow before it opens the gas valve.
Fogatti replaces a traditional mechanical sail switch with an electronic wind-pressure sensor intended to reduce startup issues caused by dust, debris or marginal airflow.
- Sensor
- Electronic
- Purpose
- Pre-ignition airflow check
SMART WIRED CONTROLLER
Heat level, mode and fault information stay visible inside the RV.
The controller supports Rapid, Standard and Sleep modes and provides diagnostic information without requiring access to the furnace cabinet.
- Modes
- 3
- Heat levels
- 4
17K–35K OUTPUT
Four heat levels instead of one fixed furnace output.
The furnace can operate at 17K, 25K, 30K or 35K BTU. Rapid mode favors recovery, Standard mode manages everyday heating and Sleep mode reduces sound to 40 dB.
Confirm the cabinet, return air and duct system before choosing the door.
InstaHeat 35K is a central ducted propane furnace. Replacement compatibility depends on more than exterior dimensions: check duct static pressure, return-air area, exhaust location, propane supply and mounting orientation.
FURNACE CABINET
17.7 × 7.8 × 20.1 inches.
The compact cabinet supports common RV replacement layouts, but clearances and access must be checked against the installation manual.
MOUNTING OPTIONS
Horizontal or vertical installation.
- Duct outlets
- 7 openings
- Outlet size
- 4-in round
- Power
- 12V DC
- Vertical mount
- Bracket required
Choose furnace output around the RV and its duct system.
The correct furnace is the one that matches the heat-loss calculation, cabinet opening and duct capacity—not simply the largest BTU number.
Swipe to compare →
InstaHeat 25K
For compatible smaller RVs and duct systems that do not require 35K output.
- Maximum output
- 25,000 BTU
- Airflow
- 220 CFM
- Installation
- Horizontal / vertical
InstaHeat 30K
For compatible RVs that fall between the 25K and 35K heating requirements.
- Maximum output
- 30,000 BTU
- Fuel
- LP propane
- System
- Central ducted
InstaHeat 35K
For larger compatible RVs that need four heat levels and stronger airflow.
- Maximum output
- 35,000 BTU
- Airflow
- 260 CFM
- Sleep mode
- 40 dB
See the furnace installed in real RV projects.
These videos show access planning, duct connections, horizontal or vertical mounting and startup outside a product studio.
Swipe to watch →
▶A complete furnace replacement
Cabinet preparation, propane, wiring, ducting and startup in one project.
▶How the alternate orientation is supported
An official walkthrough of the bracket and clearances required for vertical mounting.
▶Heating operation after installation
A practical review of startup, airflow and cabin heating in an RV.
Common sizing and installation questions.
The buy box contains the main specifications. These answers add context for ducting, mounting, door selection and propane-furnace operation.
Can the furnace be installed vertically?
Yes. Any non-horizontal installation requires the approved mounting bracket and the orientation, clearances and exhaust routing shown in the manual.
Will it work with in-floor ducting?
It is designed for central ducted RV heating and can work with compatible in-floor ducts when airflow and static-pressure requirements are met.
Can it be used without ductwork?
The furnace is designed around a central duct system. A direct outlet may move heat, but the installation still has to meet airflow, return-air and safety requirements.
How do I choose between 25K, 30K and 35K?
Use the RV heat-loss requirement, cabinet opening and duct capacity. Oversizing can create short cycling and noise; undersizing can leave the cabin cold.
What door option should I select?
Choose No Door only when the existing access arrangement is compatible. Select the black or white door when the installation requires a new exterior access panel.
Why is a vertical bracket required?
The bracket supports the furnace in a non-horizontal orientation and maintains the mounting geometry required for safe operation.
What does the electronic wind-pressure sensor do?
It checks combustion airflow before ignition, replacing the simple mechanical sail switch used by many traditional RV furnaces.
What should be checked before installation?
Confirm the 17.7 × 7.8 × 20.1-inch cabinet space, return-air opening, 4-inch ducts, 12V supply, propane pressure, exhaust location and service access.
This product is rated 4.9 of 5.0 stars.
It has received 29 reviews.
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