For many good reasons, the tankless water heater is quickly becoming a very popular hot water source for many homes across North America. Some of those reasons include that a tankless on demand water heater provides greater energy efficiency and unlimited hot water.
Another great benefit of tankless water heaters is that the maintenance is often easier to perform than on a traditional hot water heater. Bottom line, tankless models don’t require as much frequent maintenance or replacement parts, making tankless water heater maintenance less burdensome.
However, low maintenance does not mean “no” maintenance at all. To keep your tankless water heater unit in good working order you are going to need to regularly clean or replace the water line filter, clean the air filter, and flush the tank to remove any mineral buildup (i.e., limited routine maintenance).
By providing proper maintenance, the life expectancy of your unit can be expected to last at least 20 years.
Maintenance for tankless water heaters
Below are the 5 recommended steps to follow to properly perform maintenance on your tankless water heater in order to maintain the unit’s optimal performance.
Step 1 – Disconnect the power source to the tankless water heater
It is important to cut off your unit’s power supply before doing any inspection or maintenance in order to ensure maximum safety. It would be best if you shut off the main energy supply just to be sure.
Step 2 – Disconnect water supply to tankless water heater
Close the water valves to stop water from getting into the water heater. A blue valve for the cold water hose and a red valve for the hot water hose are typically present.
Step 3 – Water line filter should be replaced or cleaned
A lot of tankless water heaters have a water filter that protects against scale and sediment. These contaminants can build up and cause damage to the water heater. They also pass through your plumbing, including faucets and appliances.
There are several types of filters. Some can be reused and some will need to be replaced. Refer to the user manual for your tankless water heater to determine which filter you have. To protect your plumbing and improve water quality, you can add a water filter to your unit if it does not already have one built in.
Step 4 – Clean the air filter
Natural gas tankless water heaters will also include a filter between their fan and air intake pipe. This filter can become clogged over time with insects and dirt that can block the airflow.
Sometimes you may get an error message or have an electrical problem. It’s easy and quick to clean your air filter. It is usually as easy as taking out a few screws and rinsing the filter with water, then drying it and then finally reinstalling it in the unit.
Step 5 – Flushing the system and descaling
Descaling and flushing the tankless water heater is often the most difficult and time-consuming tankless water heater maintenance step. Even with an inline water filter, lime and calcium deposits can buildup inside the tankless heater.
It is a good idea once a year to flush the tankless unit and remove the scale build up if you have a hard water supply. This maintenance is recommended for households with water softener systems.
White vinegar or a special descaling solution (i.e., flush kit) can be used to remove scale. To cycle the vinegar through your tankless water heater, you will need a submersible sump pump.
This should take at least 45 minutes. After the vinegar has been removed, you can flush the unit with water using a garden hose connected to the hot side service valve.
Frequently Asked Questions
How often should I clean my tankless hot water heater?
Manufacturers recommend that the water heater be flushed every year. However the area in which you reside as well as the water quality may vary.
Depending on the quality of you water supply, you might need to flush the water heater a lot more frequently. You can contact a local water agency to check the water quality. Each city provides a monthly and quarterly report about water conditions.
What is hard water?
Hard water means water is rich in nutrients, particularly magnesium and calcium. When heating a system, mineral deposits (i.e., scale buildup) build up around the heat exchanger.
Over several months, the scale build up will block water flow passages, significantly changing water flow speeds. This forces water heaters to work harder when they are needed to produce heat.
How much does it cost to flush a tankless hot water heater?
If you rather hire out the job of flushing your water heater tank and avoid this messy cleaning process, a professional plumber will charge you between $150 to $200 dollars.
What happens if you don’t flush a tankless water heater?
Mineral deposits will build up within the water heater. With time this will cause a clog to build up and will prevent the heating elements from operating properly.
Your hot water could also fluctuate and overheat the system, impacting its efficiency.
What is the life expectancy of a tankless water heater?
On average, a tankless water heater unit can last up to 20+ years with proper routine maintenance.
What is the downside of a tankless water heater?
A tankless water heater is only able to heat so much water at the same time. So, if you are running multiple appliances at the same time (e.g. washing machine, shower, and dishwasher), you will get a fluctuating water temperature due to the water heater trying to provide for all three appliances at once.
What temperature should you set your tankless hot water at?
You will want to target between 100 and 115 degrees Fahrenheit for your water to be heated properly.
Do tankless water heaters consume a lot of electricity?
Estimates from the EPA state that a tankless water heater consumes up to 34% less electricity than a traditional water heater if your household uses 41 gallons or less of hot water on a daily basis.
If your home consumes more like 86 gallons of hot water a day, a tankless water heater will be up to 14% more efficient.
Bottom line, tankless water heaters require less electricity than traditional models (i.e., storage tank design).
