Downsides That Will Remind You To Avoid Tankless Water Heaters

Imagine being the last person to take a shower only to get hit with the blast of cold water just as you are covering your hair in shampoo. Not having enough hot water is one of several signs you need to replace your water heater. That may lead you to tankless water heaters, which seemingly solve the cold-shower dilemma. What might surprise you is that these on-demand hot water heaters cannot always keep up with your demands. It's also quite costly upfront, especially if you are installing the heater in an older house. Then there's the ongoing maintenance.

Deciding whether you should replace your water heater with another tank unit or upgrade to a tankless model isn't an easy decision. Comparing the pros and cons of each option gives you a better idea of what to expect. Some of the downsides of tankless water heaters might be enough to make you reconsider the option altogether. Of course, if you are still interested in a tankless model, understanding some of these downsides may help you take proactive steps to minimize the negative effects if you decide to move forward.

According to Angi, replacing your current unit with a tankless water heater could cost between $1,400 and $3,900. On the other hand, conventional tank water heaters average between $600 and $2,500 per unit. You will also likely pay more for repairs on a tankless model compared to a tank water heater. Sure, you might save money on your utility bills, but your budget should be aware of the higher costs of installation.

When you are installing a tankless water heater into an older home, you could face even higher installation expenses. Electric models need a large supply of electricity to operate properly. If your home has 200-amp service or less, the electrical system may not be able to handle an electric tankless water heater well. However, in some cases, 200-amp service may be enough. The power demands depend on the size of the specific tankless water heater you choose and how much power the appliance utilizes, not to mention the other ways you use electricity in your home.

If your home can't handle the power demands, upgrading your electrical box might be necessary, which requires a professional electrician and additional costs. If you're upgrading to 300-amp service, you can expect to pay between $1,800 and $3,500, according to Angi. Increasing to 400-amp service usually costs between $2,000 and $4,000. An electrician can evaluate your system and determine if it can handle a tankless water heater or if you'll need an expensive upgrade.

The appeal of a tankless water heater is that it heats the water as you need it. The heating is instantaneous with a steady supply of hot water, but there are limits to how much heated water the unit can produce at a time. The average production rate is between two and five gallons of heated water every minute. That's usually enough if one person is taking a shower or if running an appliance that needs hot water. But your demands may exceed those rates if you're doing multiple hot-water activities at once, such as taking a shower, washing dishes, and running a hot cycle in your washing machine.

A shower needs about 2.5 to 3.5 gallons per minute by itself. Dishwashers often use one to three gallons per minute, while washing machines need two to four gallons per minute. You might have to balance your activities to ensure everyone gets the hot water they need. If you have a large family, pay close attention to the flow rate of the water heaters you are considering to best understand how much hot water the unit can produce. Gas-fired tankless models typically have higher flow rates than electric heaters, so choosing a gas option may reduce the competition for hot water. Another possible solution is to install additional point-of-use water heaters for specific areas or appliances to provide a dedicated source of hot water to those high-use areas.

Do you notice dry skin, spotty dishes, and rough clothes? You may have a hard water problem, which can cause issues throughout your home, including in a tankless water heater. You can tell how hard your water is by using a water hardness test kit, but you may already recognize the signs and be aware of the excess minerals in your water.

Those dissolved minerals can cause damaging buildup inside a tankless water heater. The heat from the water heater pulls the minerals from the water and allows them to harden as scales inside the pipes, heat exchanger, and other components, which can cause major issues. Overheating is a common problem if the scale deposits affect the heat exchanger, which could cause the water heater to shut down. You may also notice a restricted flow of hot water due to the build-up in the pipes.

If you have hard water, installing a water softener before the water heater may help. This device pulls out the minerals to prevent the scale buildup inside the water heater. High-pressure water heaters also help cut down on sediment settling in the unit since the pressure pushes everything through the pipe quickly. It's also possible to descale your tankless water heater with vinegar if you have hard water. If you don't want to descale it yourself, schedule a professional descaling service with a local plumber.

There are a few important steps when it comes to maintaining your tankless water heater properly. Tankless units often have filters that need to be cleaned or changed regularly, including the water filter, which helps remove sediment from the water. You typically need to change this filter every six months to make sure it's effective. The system may also have an air filter in the air intake that needs to be cleaned or replaced. It's also helpful to inspect the air intake to look for blockages, corrosion, or other damage.

Additionally, flushing the system regularly to get rid of any sediment that could clog or damage components is crucial. Performing this step at least once every year is recommended, though if you have hard water or use a large amount of hot water, every six months is preferred. Conventional water heaters also benefit from regular flushing at about the same frequency as a tankless unit. Once per year is usually sufficient unless you have a large family or hard water.

While the maintenance workload is similar with both types, tankless models may require a little extra maintenance. Failing to perform maintenance on either type of water heater can lead to wear or damage that requires repairs. However, you will likely pay far more for repairs on a tankless model compared to a standard tank water heater.

A cold water sandwich doesn't have anything to do with eating, although you could experience this phenomenon in your kitchen. It happens when you get hot water right away, followed by cold water before it turns warm again. The cold water is sandwiched between the warmer water. When this situation happens, you may think that your water heater is malfunctioning, but this can be normal, even if it is annoying.

This issue happens due to the way the system works. Tankless water heaters warm the water on demand, but it can take the heat exchanger a short amount of time to heat up in some cases. If some warm water is still in the faucet or pipes, it will come out right away when you turn on the tap. However, cold water may also move through the heat exchanger or pipes without being heated. That's where the middle cold burst comes in. The water heater then quickly starts warming the water so it returns to the correct temperature. This effect tends to be more common with electric models since they take a little longer than gas to heat up.

There are other potential causes of temporary cold water bursts, including using various water sources at once. Mineral buildup from cold water could decrease the heat exchanger's ability to warm the water efficiently. If you have a gas water heater that frequently produces fluctuating hot and cold water, you might have a gas line that's too small and can't provide adequate fuel to the appliance. While there may be benefits to tankless water heaters, it's clear that there are plenty of downsides as well.