Dometic Water Heater Mixing Valve | 90029 | Atwood XT Series Only

Maintain safe, consistent hot water temperatures in your Atwood XT Series RV water heater with the Dometic 90029 Water Heater Mixing Valve. This genuine Dometic replacement is engineered for the Atwood XT Series — regulating the blend of hot tank water with cold supply water to deliver predictable, scald-safe temperatures at your fixtures. Built with a premium solid brass body and an integrated sediment screen, this mixing valve is the kind of part you install once and forget about.

What a Mixing Valve Does

The mixing valve sits between your water heater tank and your hot water distribution lines, performing two important jobs:

• Tempers super-heated tank water by blending it with cold supply water
• Delivers consistent, safe-temperature water to your faucets and fixtures

Real-world benefits:

• Scald protection — prevents dangerously hot water at the tap
• Effective tank capacity boost — lets you store water at higher tank temperatures while delivering safer mixed water, giving you more usable hot water per gallon stored
• Consistent shower temperature — less temperature drift as the tank cools
• Reduced flash risk for kids and older travelers

For Atwood XT Series Water Heaters

The 90029 is specifically engineered for Atwood XT Series water heaters. Verify your existing water heater model before ordering — Atwood made multiple water heater series, and the 90029 is XT-specific.

⚠️ NOT Compatible With Non-XT Water Heaters

The 90029 is NOT a universal RV water heater mixing valve. It is NOT compatible with non-XT water heater models, including:

• Dometic WH-Series water heaters
• Atwood G-Series, GC-Series, or GH-Series
• Suburban SW Series or other non-Atwood water heaters

Verify your existing water heater is an Atwood XT before ordering.

Solid Brass Construction

The standout build quality feature of the 90029 is its premium solid brass body:

• Strength and durability — handles years of pressure cycling and thermal stress without weakening
• Corrosion resistance — brass doesn't rust or scale the way some plated or alloy materials can
• Reduced cracking risk — solid brass handles temperature swings better than plastic-bodied alternatives
• Long-term reliability — the kind of "install and forget" part RVers appreciate

Built-In Screen Strainer Filter

The 90029 includes an integrated screen strainer filter that catches debris before it reaches the valve's mixing mechanism:

• Traps sand, dust, rust, and sediment from incoming water
• Prevents blockages that could disrupt mixing valve operation
• Reduces water damage risk from debris-induced failures
• Helps maintain proper water flow and normal heater operation

That's a meaningful detail. RV water sources (especially campground supplies) often carry sediment that can foul mixing valves over time. The integrated strainer extends valve life and reduces troubleshooting headaches.

Standard 1/2" MPT Connections

The 90029 features 1/2" MPT (male pipe thread) fittings on all three connections — the standard RV plumbing thread size for water heater and distribution applications. The matched 1/2" MPT connections at all three ports (hot inlet from tank, cold inlet from supply, mixed outlet) make it compatible with the wide range of fittings and adapters typical in RV plumbing.

Tool-Free Manual Installation

The 90029 is designed for simple manual installation with no tools required — hand-tight installation at the 1/2" MPT connections with appropriate thread sealant. The straightforward install means it's a reasonable DIY job for RVers comfortable with basic plumbing work.

Key Features

• Dometic OEM water heater mixing valve
• Solid brass construction for strength and corrosion resistance
• Built-in screen strainer filter — traps sand, dust, rust, and sediment
• For Atwood XT Series water heaters ONLY
• 1/2" MPT fittings on all three connections
• Tool-free manual installation
• Helps maintain proper water flow and consistent heater operation
• Scald protection at fixtures
• Effective tank capacity boost via higher-temp storage + mixed delivery

Specifications

• Brand: Dometic
• Part Number: 90029
• Type: RV Water Heater Mixing Valve
• Body Material: Solid brass
• Connections: 1/2" MPT (all three ports)
• Built-In Filter: Screen strainer (sediment trap)
• Application: Atwood XT Series water heaters ONLY
• NOT Compatible With: Dometic WH-Series, Atwood G/GC/GH Series, Suburban SW Series, or other non-XT water heaters
• Installation: Tool-free manual