Tankless Water Heater Maintenance: Why Annual Flushing is Critical

A tankless water heater provides an incredible, endless supply of hot water, but it is not a "set it and forget it" appliance. To keep a high-performance engine running, you have to change the oil. To keep a tankless water heater running, you must perform annual maintenance. Here is why flushing your system is non-negotiable.

The Threat of Hard Water Scale

The municipal water in Spartanburg & Greenville contains dissolved minerals, particularly calcium and magnesium. A tankless unit heats water rapidly by passing it through a narrow, highly conductive heat exchanger. As the water flashes hot, those minerals precipitate out and stick to the walls of the heat exchanger, creating a hard, crusty scale.

What Happens If You Don't Flush?

If that scale is allowed to build up, it acts as an insulator between the heat exchanger and the water. This causes several immediate problems:

• Efficiency Drops: The burners have to fire hotter and longer to push heat through the scale, driving up your gas bill.
• Water Pressure Drops: As the narrow tubes clog with calcium, the overall water pressure at your hot taps will decrease significantly.
• System Failure: Eventually, the heat exchanger will overheat, warp, and crack. Replacing a cracked heat exchanger is often as expensive as buying a brand-new unit.

The Flushing Process

To safely remove this scale, a professional plumber must isolate the unit using specialized service valves. A submersible pump is then used to circulate a specialized, non-toxic descaling solution (usually food-grade white vinegar or a safe chemical descaler) through the heat exchanger for 45 to 60 minutes. This dissolves the calcium buildup entirely, restoring the unit to factory efficiency.

Protecting Your Warranty

Almost all major manufacturers (Rinnai, Navien, Rheem) explicitly state in their manuals that failure to perform routine descaling maintenance will void the warranty on the heat exchanger. Protect your home and your wallet by letting Pipedex Plumbing & Drains handle your annual flush. Ask about our Pipedex Protection Plan, which includes this service for free every year!