Dometic Thermostatic Expansion Valve R-22 3/4 VW - Part# 290000129

DometicSKU: 290000129
Added to catalog: March 11, 2026
Last product update: June 30, 2026 at 11:13 PM
$516.05 $820.52
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Available by special order from Dometic
Availability details
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Availability details
Elkhart RV Parts warehouse0 ready to ship
Dometic warehousespecial order / expected-date item
Dometic is currently showing this as buyable with an expected ship date. See the delivery estimate below for the customer delivery window.
FREE Delivery Estimate July 15 – July 19
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The Dometic thermostatic expansion valve (TXV) regulates refrigerant flow in your RV air conditioning system, maintaining optimal cooling performance and system efficiency. This R-22 compatible valve is essential for RV owners experiencing reduced AC cooling, temperature fluctuations, or compressor issues related to improper refrigerant metering.

  • Thermostatic operation automatically adjusts refrigerant flow based on evaporator temperature
  • R-22 refrigerant compatible for legacy RV cooling systems
  • 3/4 VW (Valve Weld) connection for secure, leak-free installation
  • Prevents liquid slugging and compressor damage from improper refrigerant distribution
  • OEM Dometic engineering ensures compatibility with original RV AC systems
  • Direct replacement for failed or underperforming expansion valves
Specification Detail
Part Number 290000129
Refrigerant Type R-22
Connection Size 3/4 VW (Valve Weld)
Valve Type Thermostatic Expansion Valve
Manufacturer Dometic

Frequently Asked Questions

Q: How do I know if my expansion valve needs replacement?
A: Signs include weak or no cold air from vents, ice buildup on AC lines, compressor cycling on and off rapidly, or hissing sounds from the AC unit. A failing TXV cannot properly meter refrigerant flow.

Q: Will this valve work with my RV's R-22 system?
A: Yes, this valve is specifically designed for R-22 refrigerant systems common in older and mid-range RV air conditioning units. Do not use with R-410A systems.

Q: Do I need professional installation?
A: Thermostatic expansion valve replacement requires AC system evacuation and recharging. We recommend having a certified RV technician perform the installation to ensure proper refrigerant handling and system performance.

Why Elkhart RV Parts

We specialize in hard-to-find Dometic replacement parts and ship directly from Elkhart, Indiana — the RV capital of the world. Every part is genuine OEM Dometic equipment backed by expert support to help you get your RV cooling system running smoothly again.
100% Authentic OEM Parts

Factory-Fresh OEM Parts — the same brands installed in new RVs straight from Elkhart. Genuine, name-brand components made to order — never generic, never outdated. Sourced directly from the original RV manufacturers for perfect fit and factory-level quality.

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