Does Your House Need Multiple Water Heaters?

Does Your House Need Multiple Water Heaters?

Does Your House Need Multiple Water Heaters?Replacing your storage tank water heater with an on-demand or tankless unit can help you save energy, but before you make the switch, you need to understand key differences between these two water heating methods. First, consider how they work:

  • Tank-style water heaters can keep 40–80 gallons of water hot and ready for use, so you can use the shower, dishwasher, kitchen sink and washing machine all at once. When the tank is depleted, though, it can take an hour or more to replenish the supply.
  • Tankless water heaters begin heating water when you turn on the hot water at a faucet or appliance. An on-demand unit won’t run out of hot water, but it can’t supply more than one–two fixtures at once.

Do You Need One or Multiple Water Heaters?

If you’re used to a storage tank water heater that supplies 7.5–9.5 gallons per minute (gpm) of hot water, a single on-demand unit that supplies just 2.5–5 gpm may not be sufficient. To help you decide how many water heaters your home needs, get professional advice and consider the following factors:

  • Peak demand. To calculate your household’s peak demand, turn on all your hot water taps and appliances then note how many minutes it takes for the water to turn cold. Then, divide this figure into the number of gallons your storage tank unit holds. For example, a 60 gallon tank ÷ 15 minutes = a peak demand of 4 gpm.
  • Home size. A single tankless water heater with a flow rate matching your peak demand may be adequate if your home is relatively small with just one or two bathrooms. For a larger home with three–four bathrooms, installing two on-demand units in parallel may be necessary to meet your needs.
  • Supply distance. If you have fixtures or appliances located some distance apart, it may be advisable to install two or more point-of-use on-demand water heaters to avoid unnecessary energy losses and prolonged delivery times.

If you need expert advice about whether your Peachtree City home needs more than one water heater, contact us today at Powers Heating & Air.


Our goal is to help educate our customers in Peachtree City, Georgia and surrounding areas about energy and home comfort issues (specific to HVAC systems). For more information about other HVAC topics, download our free Home Comfort Guide or call us at 770-487-2040.

Credit/Copyright Attribution: “guilaine/Pixabay”

1 Comment

  1. It’s great how you elaborated that a single tankless water heater will be enough for a small home with just one to two bathrooms. I’m quite comfortable with how small but stylish my condominium is, but this doesn’t give me the luxury of using large appliances as full-fledged houses can. However, if I can find a plumber in the area that can get me a tankless water heater system, I’ll be able to enjoy hot showers very regularly.

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