How do you know if your tankless water heater is broken?

Author: Emery Pagac  |  Last update: Monday, January 19, 2026

Here are some common problems of tankless water heaters and potential troubleshooting steps you can follow to fix them and get them up and running again.
  1. No Hot Water Is Coming.
  2. The Water Is Too Hot.
  3. Low Water Pressure.
  4. The Unit Is Too Noisy.
  5. Discolored Water and an Unpleasant Odor.
  6. The Burner Doesn't Ignite.

What happens when a tankless water heater fails?

A tankless system can also fail in the ways that a standard gas-powered water heater or furnace can fail. The gas jets can become dirty and fail to ignite fully—or ignite at all. If the electronic ignition system breaks, the water heater won't come on and you'll end up with no hot water at all.

How to tell if a tankless water heater is bad?

To help you identify when you have a tankless water heater in trouble, we've listed several warning signs to watch for:
  1. A drop in hot water pressure. ...
  2. Lukewarm water. ...
  3. The water heater keeps shutting off. ...
  4. Unusual behavior from other appliances. ...
  5. Leaks.

How do you know when your tankless water heater is going out?

Turn on the hot water for one sink and see if it comes out cloudy, rusty, or smells bad. If some, there is trouble in your tankless heater. The system creates strange noises. Last but not least, make sure you are listening to your water heater every once in a while.

How do you know when a tankless water heater needs to be replaced?

Common signs that it's time to replace your water heater include its age (usually 10-15 years), rusty or discolored water, strange noises, leaks or pooling water around the tank, and insufficient hot water supply.

Common Tankless Water Heater Problems & How to Fix Them

What is the life expectancy of a tankless water heater?

One of the most common questions asked by consumers about tankless water heaters is how long they will last. A tankless water heater can last anywhere from 15 to 20 years with proper maintenance and operation. In comparison, a standard tank water heater normally has a working life of 10 years or less.

How much does it cost to replace an existing tankless water heater?

For an electric tankless water heater, the average cost is around $8,850. Replacing a gas tankless water heater costs approximately $4,700, while replacing an electric tankless water heater costs about $4,200. Factors such as fuel type, brand, labor, and home modifications can influence the overall installation cost.

How to tell if your water heater is broken?

How Do I Know if My Water Heater is Broken?
  1. Your Hot Water Depletes Faster.
  2. Your Water Heater Is Leaking.
  3. You Hear Unusual Noises.
  4. Your Water Is Discolored.
  5. You're Sporting an Older Unit.
  6. Don't Wait in the Cold: Replace Your Water Heater Today.

What breaks on a tankless water heater?

Here are six of the most common problems and maintenance concerns for tankless water heaters:
  • Mineral Buildup.
  • System Overload.
  • Cold Water Sandwich.
  • Air Supply or Exhaust Blockage.
  • Ignition Failure.
  • Flame Failure.

What happens if tankless water heater is not flushed?

You need to flush a tankless water heater once a year to get rid of mineral deposits and sediment that block the water flow. If you don't, this problem can cause your tankless hot water heater to stop working. You also might void the warranty by not doing it.

How to troubleshoot a tankless water heater?

First, check to ensure your tankless heater receives power. Check that the circuit breaker hasn't tripped if it's an electric unit. If it's a gas unit, ensure the gas supply valve is open and the pilot light is lit. Another common reason for no hot water is a problem with the water supply.

Can you burn out a tankless water heater?

If a heating element begins to ground out, it will stay on all the time and overheat drastically. Not surprisingly, the result will be painfully hot water – and that's just for starters. With time, the heater element will burn itself out completely. Then you'll have no hot water at all until the element is replaced.

Why is my tankless water heater not kicking on?

The first thing you should check is whether your tankless water heater is receiving power. Check the circuit breaker to ensure it hasn't tripped. If it has, reset it and see if the heater starts working again. If it continues to trip, there might be an underlying electrical issue that requires professional attention.

How often do tankless water heaters break down?

Tankless water heaters also have a long lifespan of about 20 years; double the lifecycle of a conventional storage tank water heater. For all their advantages, tankless water heaters require specific maintenance routines to ensure they perform efficiently for the long haul.

Is it easy to replace a tankless water heater?

Tankless water heater replacement is a complex process that involves the skills of a highly trained technician. Unless you are experienced and comfortable enough to solder pipe, make gas connections and follow local codes, hire a licensed professional.

Do tankless water heaters leak when they fail?

These water heaters are designed to work with low water pressure. So, a tankless water heater trying to operate with high water pressure can wear out and leak over time.

Do tankless water heaters have a lot of problems?

One of the most common problems with tankless water heaters is experiencing insufficient hot water. There could be various reasons behind this issue. If the heater is undersized for your household's hot water demand, it may struggle to keep up, resulting in lukewarm water or abrupt temperature fluctuations.

Are tankless water heaters serviceable?

Tankless water heaters need to be descaled regularly to prevent mineral buildup, and the burners need to be cleaned out.. If your water heater hasn't been properly maintained, it's likely that it will need to be replaced. However, if you've been keeping up with the maintenance, a repair may be all that's needed.

How do you know if your water heater is about to burst?

7 Warning Signs of Water Heater Explosion
  • Leaking Pressure Relief Valve. ...
  • A Consistent Popping Noise. ...
  • Rotten Egg Odor. ...
  • Brown Water. ...
  • Gas Leak. ...
  • Improper Bad Installation. ...
  • Neglecting Routine Maintenance.

Can I take a shower if my water heater is broken?

Get a portable tankless water heater

One emergency solution for escaping a cold shower is a portable tankless water heater, whether electric or gas-powered. Electric tankless water heaters are a lot easier to deal with.

How do I know if I need a new water heater?

You notice a difference in heating capacity

Over the years, that may slowly decrease until you might have a hard time taking a 10-minute shower. If your hot water runs out quickly, then you have a heating capacity problem. You might also find that it takes your water heater longer and longer to heat water up.

Are tankless water heaters expensive to repair?

The most common expenses associated with tankless water heater maintenance are labor costs, replacement parts, and annual or semi-annual maintenance checks. Labor costs can range from $50 to $150 per hour, while replacement parts can cost between $20 to $500, depending on the part's complexity and brand.

Does home insurance cover a water heater?

It's important to note that standard homeowners insurance policies typically only cover damage to the structure of your home and personal property. They do not include replacement cost coverage for the heater itself.

Can I replace my 40 gallon water heater with a tankless water heater?

Absolutely! In fact, tankless water heaters are becoming the standard for new home construction because of the energy efficiency.

Previous article
Is it hard to sell a home without a bathtub?
Next article
What is the rate of backwash water?