How to Fix a Tankless Water Heater

Today, we’ll answer some basic, common questions about tankless water heaters, repairs, and replacement concerns. This starts with the frequent question of “Why am I not getting hot water from my tankless water heater?” This is often what leads to the need to call for professional tankless water heater repair service.

There are several issues that could be the reason you aren’t getting hot water from your tankless water heater. Your power source, whether electric or gas, could be the issue, or it could be that you’ve maxed out the capacity of your tankless unit. While they don’t run out of hot water, it’s important to remember that they can only heat so much within a certain amount of time. 

For instance, somebody is showering while another person has the dishwasher running, and a third person is washing their hands all at the same time. These activities can cause the water hot to turn lukewarm in the shower and lead to a total lack of hot water in the dishwasher. There isn’t a tankless water heater repair for this situation. It is a matter of timing when these larger uses of hot water are spaced out. 

However, the lack of hot water can also be a bigger issue like one of the following: 

• Heat exchanger unplugged
• Air intake or vent is blocked
• Electric or gas supply issues
• Flame rod or ignitor has gone bad
• Burners need cleaning

Tankless water heater repairs and solutions: 

First, turn all hot water appliances off except for one and allow the tankless unit to catch up to the demand. If you’re only getting hot water with one hot water appliance at a time, you may need to upsize your tankless water heater unit with a higher flow rate unit. Other things to check are: 

• Is the electricity or gas turned on? 
• Is the water heater vent clear of any obstruction? 
• Have you kept the recommended regular inspection and maintenance? 

Why does my tankless water heater go cold?

This is another common problem for plumbing contractors. However, it isn’t always a tankless water heater repair issue when the homeowner is getting cold water sandwiched between hot water. This is caused by temperature fluctuations, and more often than not, it is a matter of the tankless water heater size being too small for the household. 

How do I know if my tankless water heater is bad?

The main reason many homeowners are going with a tankless water heater is so they never run out of hot water – a very common problem in households with kids and teens. Another reason is so they don’t have to run water waiting for the hot water to start, that is a water of a natural resource and money. 

Unfortunately, that doesn’t mean you’ll never need tankless water heater repairs or that your tankless water heater will last forever. Here are five signs that a tankless water heater repair or replacement is needed: 

• Water quality suddenly changes: If your water has suddenly became cloudy or rusty, or has dirt-like sediment in it, this is a huge hint that you may need tankless water heater repair. First call the supplier of your water, like the city water department or the water co-op and ask if there are any busted water mains. If there isn’t, then call a professional plumber to inspect your tankless water heater system and plumbing lines. 
• Water smells or tastes different: An unusual smell or taste suddenly could be the tankless water heater. Repair could be something coming from the water inlet or within your pipes, but it could be the unit too. A professional plumber can inspect and determine the situation. 
• Banging, booming sounds: If you’re hearing banging or booming sounds from your tankless water heater, repairs or replacement may be needed. Call a professional plumber to do a flush and see if that fixes the problem. If not, a new tankless water heater is in your immediate future. 
• Inconsistent hot water or water pressure: The attraction to  tankless water heaters is never having to wait for the water to heat up. So if your tankless unit isn’t getting you hot water on depend, or the water pressure has dropped significantly, you need to have a professional plumber inspect the system and be prepared to have a new unit installed. 
• Warning messages: Most of the tankless water heaters on the market have a display that shows any warnings of possible problems. Never ignore any warning displayed and call for a tankless water heater repair as soon as you notice a warning. 

Can you repair a tankless water heater?

Tankless water heaters are like traditional tank water heaters and are powered by either electricity or natural gas. Depending on the problem, tankless water heater repairs are possible with a professional trained plumber. Some examples of tankless water heater repairs are: 

• An electric unit heating element can be replaced
• A natural gas-powered tankless water heater can have the burners replaced
• Both units should be flushed annually, like a traditional tank water heater.

Can you repair a tankless water heater heat exchanger?

The tankless water heater exchanger is what allows you to take that hot shower every morning. This is the device that raises the temperature and transfers the heat from one source to another and is activated by the incoming water flow. A professional plumber experienced in tankless water heaters is able to perform tankless water heater repair by replacing the exchanger on most brands and models. 

Can you repair a leaking tankless water heater?

It can be repaired, but not by you. A leaking tankless water heater repair must be done by an experienced, trained professional plumber. If the unit is under warranty, it should be done by a plumber that is certified by the brand of the tankless unit. 

How much does it cost to repair a tankless water heater?

Professional tankless water heater repairs can cost as little as $150 and more than $800 with the average cost being around $600. With routine checkups, inspections, and flushing by a professional plumber, you can minimize the chances of needing repairs. 

What is the average life of a tankless water heater?

This is another area where the tankless water heaters outshine the traditional tank water heaters. The traditional water heaters typically need to be replaced between 10 and 12 years. The tankless water heaters can give you up to a 20-year lifespan when you have routine inspections and flushing done.