Troubleshooting Tankless Water Heater Problems

When you have a tankless water heater, you may experience problems from time to time. Here are some tips for troubleshooting those problems so that you can get your hot water back as soon as possible.

Tankless Water Heater

Tankless water heaters have many benefits. They are efficient, durable, last long, take up less space than traditional water heaters and are friendly to the environment. However, they are expensive and like any appliance, they can sometimes experience problems.

The commonest complaint we get with tankless water heaters is that they don’t seem to provide hot water as quickly as expected. Like most tankless water heaters, if your water heater does not have a buffer tank or a recirculation pump, it may take a minute or two for the water to heat up before it comes out of the tap. The pipe length from the water heater to the fixture also plays a role in how quickly you will get hot water.

Common Tankless Water Heater Issues

Here are some common tankless water heater issues and what you can do to troubleshoot them.

  • Low water pressure
  • The water is too hot
  • No hot water
  • The unit is too noisy
  • Testing for a plumbing crossover
  • The burner doesn’t ignite
  • Water temperature fluctuation
  • Water isn’t hot enough

While some of these water heater problems are easy to fix, others may require the help of a professional. If you’re not comfortable troubleshooting the problem yourself, it’s always best to call in a professional like Rick’s Plumbing.

Fixing Tankless Water Heater Issues

Low Water Pressure

  • Make sure that the utility is providing adequate water pressure to your home.
  • Don’t use too many applications at once.
  • Make sure plumbing and fixtures are free from obstructions.

The Water is Too Hot

  • The temperature setting may be too high.
  • If there are obstructions in the pipes, this can cause a build-up of heat, making the water hotter than it should be.
  • There may be clogs in the pipes or showerhead. This will reduce the flow of water and cause only a small amount of water to be heated, making it hotter.
  • Sediment build up in your tank. This will require flushing and descaling.
  • The temperature sensor may be out of position or broken. Reposition it or replace it.
  • If the output temperature sensor is broken, replace it.

No Hot Water

  • This is one of the commonest water heating system problems. It is usually due to a power or water supply issue. Check your gas or electricity supply. Also check the water shut-off valve.
  • Your tap should be opened enough and make sure that there are no obstructions in your pipes.
  • Does your gas burner’s flame rod generate a spark? If not, clean or replace it. If you have an electric water heater, check the circuit breaker.
  • Check your unit’s control panel to see if there’s an error code.

The Unit is Too Noisy

  • Is the burner burning the gas with a yellow flame instead of a blue one?
  • Make sure the fan is clean.
  • Burner flames may be unstable due to an absence of combustion air and gas pressure.
  • Irregular gas combustion due to leaks in the sealed combustion chamber.

Testing For a Plumbing Crossover

  • Shut off the cold water inlet valve
  • Open all the hot water faucets in your home.
  • If after about 10 minutes you notice water flow, it means that there is a plumbing crossover.

The Burner Doesn’t Ignite

  • Check if gas, water, and electricity are turned on and unobstructed. If you have an electric water heater, check the circuit breaker.
  • Bleed all air out of the gas line.
  • Is the vent system correctly installed?
  • Assess the flame rod and wiring harness. Are they damaged, loose, or malfunctioning?
  • Check if the flow sensor is working as it should.
  • Are you using the correct gas type and the right pressure?

Water Temperature Fluctuation

Water temperature fluctuation or cold water sandwich is when you experience a brief blast of cold water in the middle of your warm water shower. If the heater was used prior to your shower, then the warm water you felt initially was leftover heat. When the cold water entered, the heater didn’t heat it fast enough. That is why your shower was cold for a while. The longer the pipe distance, the greater the problem. 

  • Is your gas line the right size?
  • Do you have a malfunctioning flow sensor?
  • The water filter on the cold water inlet may be covered in dirt.
  • There may be a plumbing crossover when the cold and hot water mix.
  • Is the venting pipe the right length?

Water Isn’t Hot Enough

  • The water temperature may be set too low.
  • The water filter may be clogged resulting in low water flow.
  • There could be a problem with the gas supply or pressure.
  • There may be a plumbing crossover. As a result, cold water mixes with hot water, reducing the overall temperature.
  • Check the venting system. Is it clean and letting in enough fresh air for adequate combustion?
  • There may be limescale and sediment buildup in the heat exchanger. These function like an insulation that prevents the heat exchanger from transferring the heat to water. Proceed to descale and flush the deposits.

Error Codes

Modern tankless water heaters come with built-in error codes that help you troubleshoot any problems. There are many reasons why an error code may appear on your screen. The most common include:

  • A foreign object is blocking the water flow sensor.
  • There’s not enough water flow.
  • The gas pressure is too low or too high.
  • There’s a gas leak.

Flow Rate

Many tankless water heater problems are linked to the flow rate. If the water flow rate is too low, you’ll have problems like water getting cold in the middle of your shower or not enough hot water. You can resolve several of the common tankless water heater problems by making sure that the flow rate is above the minimum required level.

While you can fix some tankless water heater problems on your own, it’s always best to consult a professional if you’re unsure about anything. They’ll be able to quickly diagnose the problem and get your water heater up and running in no time. Experts have the experience and tools to properly fix any tankless water heater issues.

Plus, you could lose your warranty, put your family at risk, or cause more damage if you try to fix the problem yourself and something goes wrong. So, if you’re having any issues with your tankless water heater, don’t hesitate to call a professional for help.

Contact Rick’s Plumbing When You Need Help With Your Tankless Water Heater

If you’re having problems with your tankless water heater, call Rick’s Plumbing. We have years of experience dealing with all types of plumbing issues, including tankless water heaters. Contact us today at 203-874-6629 to schedule a service!