Although tankless water heaters can be efficient and simple to maintain, they are susceptible to problems. Here are some common issues with these heaters.

Restricted Energy Supply

If the water heater’s energy supply is cut off, it won’t turn ON. An electric water heater might have an electrical supply problem.

  • The circuit breaker has tripped
  • A short circuit is a feature of the electrical system.
  • The ignition system (electrode) has failed

Here are some things that could restrict gas flow in a gas system:

  • Incorrect setting can cause gas pressure problems, such as incorrectly setting the thermostat.
  • A closed gas valve
  • Gas supply interruption to house

If you are unable to identify or fix the problem, call a plumber.

Mineral Buildup

Some dissolved minerals are present in the water supply to your home. Some minerals build up in your heating system and remain every time you use the water heater. The minerals buildup can cause water to turn a discolored color and a bad odor. The heat exchanger can also be damaged by extreme mineral buildup.

To get rid of mineral buildup, flush the water heater frequently. The water temperature and the amount of minerals in the water will determine the degree of mineral buildup. Flushing is more important at higher temperatures and with more minerals.

Vent or exhaust blockage

The system, unless you have an electric water heater will need fresh air to burn and exhaust. Your water heater will have problems if there is a blockage in the exhaust or air supply.

A blocked air supply can lead to ignition and combustion problems. Blocked vents can lead to overheating and heating problems. They can also cause indoor air pollution. Unblocking the system is the best solution in both cases.


You can overload your water heater if you heat more water than it can handle. If you run multiple hot water systems simultaneously or open multiple hot-water faucets at once, it is possible to overload the heater. It is dangerous to overload the system because:

  • There won’t be enough hot water
  • Overworked and overheated systems can result.
  • The system can be shut down

You need to understand the water heater’s capacity in order not to overload it. Limit the amount of hot water flowing out of your system at any given time. If you have more hot water needs, such as a renovation or an addition of hot water appliances, you can increase the capacity of your water heater.


Tankless water heaters are not susceptible to corrosion because they do not heat water constantly. However, they can still corrode. Condensation around the gas burner may corrode it. A corroded burner could also experience blockage or leakage. Heat exchangers can also become corroded and overheat.

First, remove corrosion. If the corrosion has caused severe damage, replace the affected part (e.g. the burner). The water heater might need to be replaced if there is severe corrosion.


Overheating can also be dangerous for your tankless water heater. If:

  • The system is overused
  • Too high a water temperature
  • Water supply is cut off by a malfunction
  • Temperature sensors fail
  • Some obstruction blocks the airflow

The cause of the overheating is what will determine the solution. It is possible to cause irreparable damage to your water heater by overheating for too long.

You can fix most of these issues and still use your water heater. Water heater replacement is not necessary except in very rare cases. Clog Kings Plumbing is a plumbing company with over 40 years experience. We are happy to help you with your water heater problems so that you have hot water throughout the house.

This post was written by Joey Denick. Joey is the Owner and Operator of Clog Kings. At Clog Kings, LLC, we pride ourselves on our dedication and efficiency. We know you don’t have time to waste. That’s why we work fast to get your home or commercial building back up and running in no time. If you are looking for Water Heater Repair Clermont FL then look no further because we got you covered!