How to Install a Power-Vented Water Heater

Installing a power vent

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Power-vented water heater

Power-vented water heaters work the same as ordinary water heaters, but the exhaust gases are blown out with a small fan instead of rising upwards through metal pipes.

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Natural-draft water heater

The hot exhaust gases from a natural-draft water heater rise through an open draft diverter and out through a metal duct.

Natural gas or propane hot water heaters are generally less expensive to operate than electric heaters, but installing a standard vent in a house without an existing chimney is expensive. 

It’s easier to run the vent if you install a “power-vented” type of natural gas (or propane) water heater. This type of venting system is different from what you see on most gas water heaters. Most have a “natural-draft” type of vent, where the hot waste gases rise through an open draft diverter and into metal pipes,
which eventually lead to the outdoors. Running one of these vents is complicated and may be expensive. It’s best left to a professional.

In contrast, a power-vented type relies on a fan to blow the exhaust gases out. Since this method doesn’t rely on the natural buoyancy of hot air, the vent pipes don’t have to go upward. They can go out horizontally, which usually makes them much easier to install. Further, the fan dilutes the exhaust with cooler air so you can run the vents with easy-to-assemble PVC pipe. Power venting is an especially good solution for more energy efficient, tightly built homes, where a good natural draft is difficult to establish.

However, you should be aware of several drawbacks:

1. You may notice the sound of the fan. Ideally the water heater will be in a room away from the main living area so it doesn’t become bothersome.
2. You have to provide a standard electrical receptacle near the unit to supply power for the fan.
3. You have to make sure you have adequate “make-up” air to replace the air being blown out.
4. And finally, power-vented water heaters cost at least 50 percent more than a natural-draft water heater. You can find power-vented water heaters wherever water heaters are sold; almost every major water heater manufacturer makes them.

If you decide to install one yourself, read the instructions carefully and make sure to follow all venting procedures. And call your local building department and ask if you need a plumbing permit to do the work.