Complete Guide to Oasis/ITR Hydronic Heater Service Kits — Annual, 3-Year, and 5-Year Maintenance

If your RV or coach runs an Oasis hydronic heating system by International Thermal Research (ITR), regular maintenance isn't optional — it's what keeps your system lighting reliably, heating efficiently, and lasting for years. ITR designed their service schedule around three tiers: annual, 3-year, and 5-year kits — each building on the last to cover every wear component in the burner.

This guide explains what's in each kit, which kit fits your Oasis model, and how to stay on top of the maintenance schedule so your heater is ready when the temperature drops.

Why Oasis Service Kits Matter

Oasis heaters use a patented low-pressure diesel burner that runs cleaner and quieter than traditional high-pressure systems (like the Webasto DBW-2010 used in Aqua-Hot units). That lower pressure is gentler on components, but the burner still relies on precision parts — fuel nozzles, ignitors, filters, and flame sensors — that wear out over time.

Skipping service leads to predictable problems:

• Hard starts or no-start conditions from a clogged nozzle or worn ignitor
• Sooting and smoke from degraded combustion components
• Reduced efficiency as carbon buildup insulates the combustion chamber
• Expensive emergency repairs that could have been prevented with a $100–$200 kit

ITR recommends following a strict rotation: annual kit → annual kit → 3-year kit → annual kit → annual kit → 5-year kit, then repeat. This ensures every component gets replaced at the right interval.

Oasis Models and Their Service Kits

ITR currently offers five Oasis hydronic heating systems. Each has its own set of service kits because nozzle sizes, filters, and ignitor types vary by model:

Not sure which Oasis model you have? Check the label on the top of the heater unit for the model number and serial number. The CH50 is the most common in larger Class A coaches, while the Combi and Zephyr are found in smaller motorhomes and trailers.

What's Inside Each Service Kit

Annual Service Kit (Years 1, 2, 4)

The annual kit covers the parts that wear fastest under normal operation:

• Fuel filter — Prevents debris from reaching the nozzle and burner
• Compressor air filter — Ensures clean combustion air supply
• Nozzle filter and nozzle O-ring — Maintains proper fuel spray pattern
• Ignitor — Provides reliable spark for burner startup (inspect annually, replace every 2 years)
• Nozzle (in some models) — Replaced annually to prevent carbon buildup and poor atomization

This is the bare minimum to keep your Oasis running clean. If you only do one thing each year, replace the fuel filter and nozzle components.

3-Year Service Kit (Year 3)

Includes everything in the annual kit plus:

• Digital flame sensor (photodiode) — The flame sensor monitors combustion in real time. After three years of heat cycling, it degrades and can cause intermittent lockouts or false flame-out signals. The 3-year kit includes a fresh sensor to restore reliable flame detection.

5-Year Service Kit (Year 5)

Includes everything in the 3-year kit plus:

• Additional wear components specific to your model — Depending on the Oasis model, this may include replacement fuel pump components, additional gaskets, and other items that reach end-of-life at the 5-year mark.

The 5-year kit is the most comprehensive service interval and effectively refreshes the entire burner's consumable components.

Service Schedule at a Glance

Pro tip: Always run the heater and confirm it's working before you start the service. This proves the system is functional and helps you identify any pre-existing issues. After service, run it again to verify everything is operating correctly.

General Annual Maintenance Checklist

Beyond the kit components, ITR recommends these additional checks every year:

1. Inspect all rubber hoses — Look for cracks, leaks, weak spots, and corrosion on fuel, water, and coolant lines. Replace if needed.
2. Check hose clamps — Look for wear under clamps and signs of corrosion. Tighten or replace.
3. Inspect the exhaust system — Check for blockages, corrosion, or damage. Ensure the exhaust tip is clear.
4. Check coolant level and pH — Top off if low. Replace coolant every 3 years (36 months).
5. Inspect the compressor and combustion fan — Look for corrosion and wear. Listen for unusual sounds.
6. Check electronic control board connections — Ensure all connections are tight and free of corrosion.
7. Vacuum the combustion chamber — ITR recommends cleaning the combustion chamber and exhaust every 1,000 hours of operation.

Oasis vs. Aqua-Hot: How Maintenance Differs

If you're coming from an Aqua-Hot background, there are a few key differences with Oasis maintenance:

Both systems reward consistent annual service. The biggest difference is that Oasis kits are specifically tailored to each model with exact part numbers included — there's no guesswork about which nozzle or filter to buy.

Where to Buy Oasis Service Kits

Hydronic Heating Warehouse stocks the full lineup of ITR Oasis service kits for every model and service interval. Each kit ships with the correct OEM parts for your specific heater — just match your model number to the right SKU.

Popular kits:

• SKU 2150 — Annual Service Kit for Oasis CH50
• SKU 2160 — Annual Service Kit for Oasis NE-S
• SKU 2163 — Annual Service Kit for Oasis NE
• SKU 2166 — Annual Service Kit for Oasis Combi
• SKU 2170 — Annual Service Kit for Oasis Zephyr / Hurricane

Also available: Gar-Ber fuel filters (FLE-120-100) and Racor spin-on fuel filters for supplemental fuel filtration.

Final Thoughts

Oasis hydronic heaters are built to last, but only if you stay on top of the maintenance schedule. The annual/3-year/5-year service kit system makes it straightforward — pick your model, pick your year, and the kit has everything you need.

Don't wait until the first cold night of the season to find out your heater won't fire. Order your service kit now, spend an afternoon doing the work, and head into winter with confidence.

Browse the complete selection of Oasis ITR Service Kits at Hydronic Heating Warehouse.