Your Navien tankless combi boiler or water heater is one of the most efficient heating systems on the market. It provides endless hot water and reliable home heating — all while saving energy and space. But like any high-efficiency system, regular maintenance is key to keeping it running safely and efficiently.
One of the most important parts of annual maintenance is flushing the heat exchanger. Here’s why it matters, what happens during a flush, and why it should be done every year.
What Is a System Flush?
Flushing your Navien involves circulating a cleaning solution (typically a mild vinegar or descaling agent) through the system’s heat exchanger. This process removes mineral buildup, also known as scale, that accumulates inside the unit over time — especially in areas with hard water.
Without regular flushing, these minerals can coat the internal surfaces of the heat exchanger, restricting water flow and forcing your unit to work harder than it should.
Why Flushing Is Essential
- Protects Efficiency
Scale buildup acts like insulation on the heat exchanger. That means the burner has to run longer and hotter to heat the same amount of water. A yearly flush restores your system’s peak efficiency and helps maintain low utility bills. - Prevents Costly Damage
Mineral deposits can cause overheating, corrosion, and even leaks inside the heat exchanger. Replacing that component can cost thousands of dollars — but a simple annual flush prevents those issues. - Ensures Consistent Performance
Flushing helps your Navien deliver steady water temperature and pressure. If you’ve noticed longer wait times for hot water or temperature fluctuations, scale buildup may be the cause. - Extends the Life of Your System
With proper maintenance, Navien units can last longer. Neglecting flushes can cut that lifespan dramatically. - Protects Your Warranty
Navien’s warranty guidelines recommend annual professional maintenance, — including a system flush by Aspinwall Plumbing. Skipping this step can void your warranty coverage if problems occur.
What’s Included in a Professional Navien Flush by Aspinwall Plumbing
When you schedule annual service with Aspinwall Plumbing, our certified technicians will:
- Inspect and test your system for proper operation
- Check for leaks, corrosion, or error codes
- Isolate the heat exchanger and connect flushing hoses
- Circulate a cleaning solution through the system
- Rinse the unit thoroughly with fresh water
- Clean inlet filters and inspect combustion cycle
- Inspect gas pressure, condensate drainage, and venting
- Reset and test the system for full operation
The process typically takes about 1 to 1.5 hours — and gives you peace of mind knowing your Navien is clean, efficient, and ready for the heating season.
How Often Should You Flush?
Navien recommends flushing the system once every 12 months under normal conditions.
If you live in an area with hard water or notice reduced hot water performance, you may need it more frequently.
The Bottom Line
Regular maintenance is the best investment you can make in your home’s comfort and efficiency. A yearly flush:
- Keeps your Navien system running like new
- Prevents expensive repairs
- Reduces energy costs
- Ensures reliable hot water all year long
Schedule Your Annual Navien Flush with Aspinwall Plumbing
At Aspinwall Plumbing, our licensed technicians are Navien-certified, service specialists and experienced with all makes and models of tankless and combi systems. We’ll perform a complete annual service to keep your system efficient, safe, and within warranty.
Call us today or book online to schedule your Navien annual maintenance service.
Your home will thank you with better comfort and lower energy bills.