Tuckers Air Conditioning, Heating & Plumbing Blog

Most Common Tankless Water Heater Problems


Tankless water heaters are innovative and extremely helpful for many homeowners, but they’re not perfect. Even your efficient tankless water heater can still runs into its fair share of problems.

At one point or another, you’ll need water heater service in Bethesda, MD for your tankless water heater. We’re here to tell you about the most common problems you’ll run into so you can know what to expect.

Mineral Buildup Over Time

Hard water has a high concentration of minerals inside of it, as opposed to soft water. The problem with hard water is that minerals can build up in your water heater over time. This is normally a problem that people only think occurs in storage tank units, but that’s not the case.

Mineral buildup occurs no matter what, but it’s expedited by failing to replace your water filters. Your tankless water heater requires a new filter every six months and sometimes sooner if you have hard water.

During maintenance, technicians will flush your tankless water heater to remove as much scale buildup as possible. There are also kits you can use at home to flush your own tankless water heater, though these are often not as thorough as the service that a professional provides.

To avoid mineral buildup to the best of your ability, change your filters, keep up on professional maintenance, and consider installing a water softening system. This will reduce the amount of minerals that make it to your tankless water heater in the first place.

Ignition or Flame Failure

If there’s a problem with ignition or a complete flame failure, your water heater isn’t firing up to actually heat the water. This can happen for a few different reasons.

  • Insufficient Airflow: Your tankless water heater requires sufficient airflow to help support it. If there isn’t enough air intake, it won’t heat your water properly.
  • Not Enough Gas Supply: Thankfully this doesn’t always indicate that it’s a problem with your tankless water heater, but it still points to an issue with the gas source.
  • Clogged Ignition Plug: Your ignition plug could simply get dirty over time from use. If this happens, it could prevent your water heater from doing its job.

Exhaust Blockage

Your tankless water heater has an exhaust. It’s a bit different from the exhaust on a storage tank water heater, but the concept is the same. It’s removing harmful gases and putting them outside.

If your exhaust is clogged or dirty and not sufficiently pulling those gases out, the sensor inside of your water heater will detect the problem and shut down. Simply put, poor exhaust will cause your unit to turn off on its own.

A professional will clean your tankless water heater during maintenance while removing any built up debris.

Tankless Water Heaters Need TLC, Too

Regular maintenance is critical for the longevity of your tankless water heater. While tankless water heaters have an expected longer lifespan than storage tank water heaters, that can only be fully realized with proper maintenance and timely repairs.

Contact Tuckers Air Conditioning, Heating & Plumbing today to schedule your water heater maintenance and repairs.