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What Are The Most Common Problems With Tankless Water Heaters?

tankless water heater
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Tankless water heaters are a great investment for your home or office. They are very efficient, low maintenance, and can help you save money by heating water on demand. With technology advancing, tankless water heaters are becoming more eco-friendly.

Tankless water heaters heat your water as you need it. When the faucet is turned on, water flows through the pipes and over the heating coil. The heating coil heats the water by using either electricity or gas. Since the water is only heated on demand there’s no heat loss or wasted energy.

The Most Common Tankless Water Heater Problems

Tankless water heaters are environmentally friendly however, problems can still occur if something isn’t working within the heater. Below is a list of the most common tankless water heater problems:

1. Buildup Of Minerals

It doesn’t matter if you have a tankless water heater or a traditional one, you always need to be on the lookout for mineral buildup. South Florida has hard water, hard water is water with a high mineral amount, and the harder the water the higher risk of mineral buildup damage. ​​​​​​Magnesium and calcium are two of the most common minerals to cause buildup in your water tank and left unaddressed can often cause damage to the tank.

It’s important to have a plumber service your water tank to check for mineral buildup and debris. You can ask your technician to flush your water heater every six to twelve months to keep the buildup and debris to a minimum.

2. Overloaded Systems

Simultaneous hot water uses, like multiple showers running, can overload your water heater depending on its capacity. Your tankless water heater might find it difficult to provide all the hot water you need or shut off due to a system overload. If that happens you must lower the demand for hot water by lowering the simultaneous applications, or you might need to reset your unit.

However, if it becomes overloaded often, you should think about upgrading to a larger capacity heater. You might consider it a large investment, but it can save you money overall due to less energy being needed to heat water.


3. Blocked Exhaust Or Air Supply

With some tankless water heaters, they will display a code to let you know of blockages in your exhaust or air supply. This is an indication that your heater is experiencing problems with either venting or combustion air.

Your technician will inspect all the vent-related pipes to make sure they are free of puncture holes and are connected correctly. They will also make sure your heater is installed in the right area, as things can block your air supply and cause fire hazards. They will also inspect all vents outside the home to remove any wasps nests, rodents, or bird nests that could potentially block your venting.

4. Failure To Ignite

You can have several reasons why your heater would fail ignition. The most common problem is caused by a low gas supply. Always make sure that your tank’s gas is full to avoid this.

Another reason is if your water valves or gas valves aren’t opened all the way, this can cause the failure to ignite.

If neither of these two steps resolves the igniting issue then you should contact a professional plumbing company to fix the problem.​​​​​​

5. Flame Related Issues

Flame failure is caused usually by an electrical or gas pressure issue. Similar to ignition failure, ruling out a low gas supply or a forgotten bill for gas is the first step. Other causes of flame failure include regulator failure, venting, combustion problems, or a small gas line. Calling a professional is recommended if the first two steps don’t resolve it.

Trust Art Plumbing, Air Conditioning & Electric For All Your Plumbing Needs

Our team has the skills, knowledge, and tools to provide you with all your plumbing needs. Don’t hesitate to call the plumbing professionals at Art Plumbing, Air Conditioning & Electric – we’re at your service! Contact our team today at 1-800-475-1504 to schedule a consultation.


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