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FREE USPS GROUND ADVANTAGE SHIPPING on items OVER $75.00 (UNDER 1 LB.) based on the weight per item. If you can't find a part you are looking for, call or text us at 970-518-3085! Holiday Notice: Please be advised that we will be closed for the holidays on December 24–26, 2025, and December 31, 2025 through January 2, 2026.
FREE USPS GROUND ADVANTAGE SHIPPING on items OVER $75.00 (UNDER 1 LB.) based on weight per item. If you can't find a part you are looking for, call or text us at 970-518-3085! Holiday Notice: Please be advised that we will be closed for the holidays on December 24–26, 2025, and December 31, 2025 through January 2, 2026.
Model 400D (Diesel) - AHE-400-D02

Model 400D (Diesel) - AHE-400-D02

by Aqua-Hot
Save 8% Save 8%
$7,964.90
$7,964.90 - $8,337.63
$7,964.90
$7,327.71
$7,327.71 - $7,663.17
$7,327.71

The Aqua-Hot 400D (Diesel) Hydronic Heating System used in mid-size motorhomes and RVs to deliver consistent interior heat and continuous hot water. The 400D is a diesel-powered, on-demand system designed for reliable, quiet operation in all seasons.

Important Information:
  • All-in-One Heating Solution – Provides both interior heat and continuous domestic hot water through a single, integrated system.
  • Recommended Antifreeze Replacement – Requires approximately 9 gallons of red or green antifreeze.
    Click here to purchase antifreeze separately
Heater Includes:
  • 400D Aqua-Hot System
  • Aqua-Hot Reporter Controller
  • Fuel Filter Assembly
  • Exhaust Elbow with Two Nipples
  • Overflow Bottle with Fluid Level Sensor Kit
  • 2-Year Warranty
WARNING: PROFESSIONAL INSTALLATION RECOMMENDED
WHEN REPLACING AHE-400-D01, THIS PART IS REQUIRED 
  • Harness Adapter for Coach 
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***  2 Week Lead Time Not Including Shipping Days ***

PRODUCT SPEC SHEET, MANUALS & GUIDES

Compact Hydronic Heating

Compact Hydronic Heating

  • Dual-Fuel Heat Generation: Combines an electric
    element with diesel or propane fuel source.
  • Single, Self-Contained Unit: Delivers residential-style interior heating with the ability to deliver a luxurious supply of continuous hot water at 110ºF-120ºF at a rate of 1.5 gallons per minute. It’s just like home.
  • Common Size Configuration Line-Up: Simplifies installation and on-the-line product changeovers.
  • Fast Installs: Zone port outlets are located on top of the tank for easy connection access. Mounting tray facilitates air intake, exhaust routing and fluid evacuation.
  • Aqua-Hot 400P: The propane hydronic system that puts 5th wheel and Class B into Class A Comfort Zones with a single system.
  • Owner-Friendly Diagnostics: Touch-screen Reporter monitors the Aqua-Hot & coach to provide real-time info to coach owners & service technicians. Compatible with RV-C or I/O Controls.

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