This is a Hammer

Tank or Tankless Hot Water Heater?

Q: I’m thinking of switching from a traditional hot water heater to a tankless water heater. With three teenagers in the house, the current tank heater is just not adequate to keep hot water available. Will a tankless heater solve the problem? And which is better, an electric or gas heater? – Sal in Southern California

A: While I like the concept of tankless water heaters – they provide hot water on demand, rather than storing water in a tank and keeping it warm – it’s really important for homeowners to do their research before deciding to jump to this system.

Electric tankless heaters, for example, look like a good deal up front. They cost about a third to one-half as much as gas tankless heaters. However, installation can be expensive: most electric heaters require a dedicated 30-amp circuit, meaning an electrician will have to come in to properly wire the house. In older homes, the installation can be pretty painful on the wallet.
Gas tankless heaters cost more up front, but installation may not be as expensive. A qualified installer will need to set up the gas connection, and your gas system may need some modification.

With either type, you still will have to deal with the problem of adequate hot-water supply. Placing high demand on the heater – such as running a shower, the dishwasher and the hot water tap in a sink at the same time – will make it more difficult for the unit to heat water to the correct temperature, meaning everybody starts getting tepid water.

Homeowners I’ve spoken with who have tankless heaters are generally pretty happy with them. But they have experienced a few issues, such as not knowing they need to flush the heating system once per year (and more often in a hard-water environment). None complained about having inadequate hot water – either they selected the right-size system for their house, or they adjusted their water use to the rate at which the water gets heated.

Because of the expense involved, find out how much water your family uses and track how much hot water is used during each day. Talk with the tankless heater dealer about the right system based on your needs, compare average annual costs (in electricity or gas) of the system compared to a traditional tank heater, and make sure you know up front what installation will entail and how much it will cost.

HOME TIP: Tankless heaters can suffer from mineral scale buildup in the heat exchanger. Talk to the manufacturer about installing a flush valve so that you can flush out buildup annually and extend the life of the unit.

Send your questions or comments to, or write This Is a Hammer, c/o King Features Weekly Service, P.O. Box 536475, Orlando, FL 32853-6475.© 2014 King Features Synd., Inc.

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