How Do Tankless Water Heaters Work

Tankless water heaters are becoming more and more common, partly because of how efficient and small they are. You may also hear them referred to as “on-demand water heaters” because they only heat and distribute hot water when it is required.

Tankless systems aren’t constrained by the size of their tank, unlike conventional tank-style water heaters, because they can produce hot water on demand.

      How a Tankless Water Heater Works
  • The hot water tap is turned on

By turning on the hot water, you can ensure that hot water is running through your pipes. Of course, that doesn’t necessarily make sense in the modern world. Make careful to turn the single knob toward the hot water if you only have one. It’s a lot easier if you have two knobs, though. Turn the hot water knob to let the hot water go through the faucet.

  • Water enters the heater

What can you anticipate now that the hot water is running? You anticipate that hot water from a conventional water heater will pass through your pipes as it leaves the tank. In contrast, cold water from a tankless water heater actually passes through sensors that trigger the internal computer and begin the process.

  • The water flow sensor detects it

As soon as the inbuilt computer is activated, it determines how hot the burners must be to heat the water to the proper temperature. Either a gas burner or an electrical element can be used for this. In either case, it offers a continuous flow of hot water without the need to wait for a tank to refuel.

The burner is automatically lit by the computer.

What is the real mechanism by which the tankless water heater produces all that hot water? The water is heated by the burner and circulated around a heat exchanger until the desired temperature is reached. The water then leaves the tankless water heater and starts moving through your pipes until it reaches its destination.

                         Common Problems with Tankless Water Heaters

Tankless water heaters have great promise for cost savings, space savings, and energy efficiency. However, some problems can undercut those advantages, so it’s critical to comprehend what the most frequent concerns are and how to avoid or address them.


Even distribution of power prevents a system overload. A system overload occasionally causes the heater to completely shut off.

Understanding your heater’s capacity and how many various appliances it can support simultaneously will help you avoid a system overload. However, if the problem persists, seek expert assistance. It could be necessary to think about improving your heater or perhaps purchasing a second heater to make up the shortfall.

Effect of a Cold-Water Sandwich

When one person exits the shower and the next person enters right away, this is known as a cold water sandwich. The water starts off hot but quickly cools off for a brief period of time (up to a minute) before heating back up.

This occurs because even though the water hasn’t been heated after the shower has been turned off, there is still some hot water in the pipes. Cold water follows this hot water as it exits the faucet. The water shouldn’t be cold for too long because the tankless water heater will be working to heat it back up to room temperature.

Buildup of Minerals or Sediments

A buildup of mineral or silt may make the water heater and the pipes partially or completely blocked. Systems with iron pipes and components are susceptible to rust, which causes iron silt to accumulate throughout. Homes with hard water may see scale building as a result of calcium and magnesium minerals.

Flame or Ignition Failure

I can’t get my tankless water heater hot enough. If the flame fails to ignite or hold, as may be the case with the inquiry you are posing, it is probably because of an electrical or gas line problem. Your heater won’t be able to heat the water either way. Examine the reason behind your gas supply shortage. An unpaid bill can expel your services temporarily.

       How To Install a Tankless Water Heater
  • A licensed, professional plumber can install gas lines.
  • Turn off the hot water tank’s gas and water. Remove the old tank and drain the water from it.
  • Consider a bigger gas line to connect the gas meter to the new water heater.
  • Drill a hole near the water heater on the outside of the home using the hole saw. Pass PVC pipes through the hole for the vent and fresh air intake.
  • Utilizing 34″ copper pipe, join the hot lines coming out of the heater and the cold-water supply line to the water heater.
  • An electrical outlet is necessary for an on-demand water heater. An electrician can help in this special situation.
  • The farthest plumbing fixture can have a crossover valve fitted to enable the built-in recirculation pump to maintain hot water on hand.
  • Test the water heater by turning on the power, gas, and cold-water supplies. Learn More About Us:When it comes to finding a great company that can fix problems, visit Acts Plumbers Tulsa of Service Plumbing page:  About Us | Plumbing Tulsa | Acts of Service Plumbing and then give us a call!

    Who are the companies we have had the pleasure of serving? Visit Paul Davis’ website to learn more at Paul Davis Corporate – Restoration and Emergency Service Provider.