Why Isn’t My Tankless Water Heater Heating Water?

Tankless water heaters are a great upgrade—energy-efficient, compact, and designed to provide hot water on demand. But what happens when yours suddenly stops working? If your tankless unit isn’t heating water, there are several potential reasons behind the issue. Let RAM Plumbing, your trusted plumber in Oro Valley, AZ, break it down for you below.

Check the Power or Gas Supply

This might sound basic, but it’s always the first place to start. If your unit is electric, check the circuit breaker to ensure it hasn’t tripped. For gas models, experts in plumbing repairs recommend making sure the gas valve is fully open and the supply hasn’t been interrupted.

Inspect the Water Flow Rate

Tankless water heaters require a minimum flow rate to activate. If the flow is too low—due to a clogged faucet aerator or a partially closed valve—the unit might not turn on. Try running a different tap to see if the problem persists.

Look for Error Codes

Modern tankless water heaters often feature a digital display that shows error codes when something goes wrong. These codes can identify a range of issues, from ignition failures to faulty temperature sensors. If you’re unsure what the code means, it’s best to consult your user manual or reach out to a trusted plumbing company for expert help.

Sediment Buildup

When hard water flows through your system, it can leave behind mineral deposits that accumulate in the heat exchanger. This buildup restricts performance and may lead to inconsistent heating. Scheduling routine flushing through professional plumbing services helps prevent long-term damage and keeps your unit running smoothly.

Cold Weather Problems

Freezing temperatures can be brutal on water lines, especially in colder regions where pipes are more likely to freeze or burst. Even if your tankless unit has built-in freeze protection, it still relies on power to operate. If your system shuts down, emergency plumbing services can help restore function before serious damage occurs.

Call the Tankless Water Heater Experts at RAM Plumbing

If you’ve gone through the basics and your tankless water heater still isn’t heating, it’s time to call in the pros. RAM Plumbing specializes in diagnosing and repairing tankless water heater issues quickly and efficiently. Don’t let cold water ruin your day—contact us today to get your hot water flowing again!