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Tiffin Motorhomes Knowledge Base

Do I have to bypass the water heater when I winterize my motorhome?

Yes—you absolutely need to bypass the water heater when winterizing your Tiffin motorhome, unless you enjoy paying for a new one. Here’s why and how:

🔧 Why You Bypass the Water Heater:

  • Prevent antifreeze waste – Your water heater holds 6–12 gallons. You don't want to fill it with RV antifreeze—it’s expensive and unnecessary.
  • Protect the tank – Leaving water in it (without draining or bypassing) can crack the tank if it freezes. That’s a $700+ mistake.

🧰 What You Need to Do:

Drain the Water Heater

  • Turn it off (electric + LP).
  • Let it cool, then remove the drain plug (or anode rod if it’s Suburban).
  • Open the pressure relief valve to vent air and help it drain faster.

Bypass the Water Heater

  • Use the bypass valves located near the back of the water heater. Most Tiffin motorhomes have either:
    • A three-valve system (hot, cold, and cross-over)
    • Or a one or two-valve auto-bypass (especially in newer models)

Then Winterize

  • Once bypassed, you can pump antifreeze through the rest of the plumbing without filling the water heater.

 

⚠️ If You Don’t Bypass It:

  • You’ll waste gallons of antifreeze
  • You risk damage if water is left inside
  • You’ll create a major headache come spring
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