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Ken Neyer Plumbing, Inc. Blog

Do Tankless Water Heaters Need to Be Sized?

tankles-water-heater-repairHow do you determine how large a storage tank water heater you need for a home? The sizing job is something you’ll need to have an expert plumber handle, but the basics of sizing this type of water heater is something anybody can understand: the more hot water demand there is in the house (usually because of the number of people in the household), the larger the storage tank itself needs to be.

But what if you’re planning to install a tankless water heater for your house? As the name indicates, a tankless water heater doesn’t have a storage tank at all. Instead, it applies heat to water as it moves through the unit via a heat exchanger. The water is heated as it is needed (or “on-demand,” which is another name for this type of water heater). So, does this mean there isn’t any need to size a tankless water heater because one size fits all?

No, not at all! We’ll go into a bit more depth about how a tankless water heater works so we can explain the importance of what goes into sizing one to match household hot water demands.

Tankless Water Heaters Have Limits with Hot Water Delivery

You may have heard that one of the benefits of tankless water heaters is that “they won’t run out of hot water.” This is true … to an extent. Because a tankless system doesn’t store any hot water, it can’t run out of a supply of it. The heat exchanger simply heats up more as the demand continues. However, a hot water heater can be overwhelmed because of large demand from multiple taps. Any specific tankless water heater has an upper limit on the amount of water it can heat at one time and the flow rate it can handle.

In other words, if you live in a household where there is often more than one hot water tap or appliance running at once, such as busy showers in the morning, a more powerful tankless system must be installed. Don’t go for a smaller system to attempt to save money! You’ll end up with a water heater that wastes money trying to keep up—plus you’ll have lukewarm showers.

The Numbers of Sizing a Hot Water Heater

How do professionals measure the power of a tankless water heater? The crucial numbers are the maximum temperature rise possible (in degrees) at a given flow rate (in gallons per minute). Sizing a water heater requires taking stock of the various water-using appliances and fixtures and the frequency of use to determine temperature rise and flow rate for the water heater. For example, a shower has an average flow rate of 2.5–3 gallons per minute and a temperature of 104°F. The professionals will calculate the water heater temperature rise and flow rate necessary to meet the demands of the appliances,

No matter what types of water heaters in Mason, ON you’re interested in having installed in your house, you can rely on our trained and licensed plumbers to find the ideal new unit, correctly sized. You’ll have a great water heater that easily meets the comfort requirements of your entire household.

Ken Neyer Plumbing, Inc. serves the Greater Cincinnati area with quality plumbing, and we have 24-hour service available.

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