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Why Is My Tankless Water Heater Running Hot and Cold?


tankless water heater

There are a multitude of benefits to investing in a tankless water heater for your water heating needs rather than the traditional storage tank. For instance, tankless water heaters are more efficient than traditional models. This is because they are not subject to standby energy loss in the way that a tank model is.

Tank water heaters store a large amount of hot water, and when it’s not used promptly, the air surrounding the tank can cause it to cool off, wasting your energy. Tankless water heaters also take up far less room than their storage tank counterparts, and tend to last longer too. However, if you’re thinking of investing in a Pocatello, ID tankless water heater installation, there are some important factors to keep in mind.

Problems with Tankless Water Heater Temperature

Tankless water heaters are not immune to problems. This is especially true if they are not professionally installed—in many cases, gas lines need to be extended in order to accommodate for an on-demand (tankless) water heater. In all cases, tankless water heaters must be property vented. If neither of these factors are properly addressed, then the tankless water heater might not be able to meet the demand being placed on it and will fail to work, as its computer system will be overloaded.

Another problem that tankless water heaters can run into is that of a cold water sandwich—a plumbing term given to sudden temperature fluctuations, when your tankless water heater produces hot and cold water intermittently.

This can be caused by:

  • An improperly sized gas line, as mentioned above.
  • A plumbing system crossover where there shouldn’t be one.
  • Improperly lengthened venting pipes.
  • Damaged flow sensor—something that should be checked during your annual plumbing maintenance appointment.
  • A dirty water filter on the cold water inlet.
  • Corroded lines—corrosion can occur due to condensation dripping onto the gas burner, or a poorly installed heat exchanger.

Finally, another issue that homeowners often find with their tankless systems—if not properly installed and maintained—is mineral buildup. We’re talking about the accumulation of calcium and magnesium. This is otherwise known as hard water. Hard water can be and is a problem for pipes—creating hard scale within them that leads to clogs and/or corrosion.

A water softener will not only resolve this problem, but can improve your quality of life too, by making your showers and baths more refreshing, helping your drinking water taste better, and even helping your laundry last longer. If mineral buildup has already occurred in your tankless water heater’s lines, then you will need a professional to clean these lines before continuing to use your water heater system.

Fend Off Tankless Water Heater Problems with Maintenance

Be sure to schedule an annual plumbing maintenance appointment so that our professionally trained and highly experienced plumbers can fully assess your tankless water heater, water softener system, and the rest of your plumbing components. Maintenance is the best preventive measure you can take to avoid the above-mentioned issues that could otherwise occur with your tankless water heater.

Advanced Home Services is the standard when it comes to providing great service. Contact us for comprehensive plumbing services today!

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