The new National Appliance Energy Conservation Act requirements for water heaters take effect this month — April 16. These energy-efficiency requirements will affect you — and your clients — because as efficiency increases, so does the size of the water heater.

“The new water heater regulations will have a significant effect on homeowners, particularly those with an aging or failing unit that will need to be replaced in the near future,” explains Bridget Kidd, director of residential and commercial programs for the Propane Education & Research Council. “In order to increase their energy efficiency, 30-gal. to 50-gal. tank water heaters will require additional materials and insulation. These changes will likely increase their size by approximately 2 in. in diameter and up to 6 in. in height.”

The size increase may not sound significant, she says, but it has the potential to cause major problems for a homeowner who wants to replace an existing storage tank water heater with a new model that has the same capacity. “For example, a homeowner with a 50-gal. tank water heater may need to downsize to a 40-gal. tank model because a new, wider, taller 50-gal. tank may no longer fit in the small utility closet where the previous tank was located,” Kidd notes.

For plumbers, this can result in tricky installation issues in homes with small mechanical rooms.

“One thing plumbers need to worry about is if the new water heater models are going to fit,” agrees David Ariano, president of Highland Park, Ill.-based Ravinia Plumbing and Heating. “If a water heater is already shoe-horned into a tight space, they may not fit going forward. The problem with making them taller is the exhaust flue pipe has to have a certain pitch to it. If you make the water heater too tall, you start messing with the ability to have the exhaust leave the unit and go up the chimney properly.”

For Ryan Poust, owner of the Sparta, N.J-based Mr. Rooter franchise, the issue is replacing 80-gal. electric water heaters, which are prevalent in the area, with heat pump water heaters.

“Anything over 55 gal. needs to be changed to a hybrid electric heat pump water heater; size constraints and makeup errors are going to be issues,” he notes. “Heat pump models work off outdoor ambient temperature or indoor ambient temperature, so you need a lot of air passing through, or air for the piece of equipment to utilize, in order to absorb the heat from the air to transfer into heat for your water.”

A homeowner with an 80-gal. electric water heater may be able to use two smaller 40-gal. units and twin them up, Poust adds, but he’ll still need the extra room for another water heater. “So the space issue is really going to be the big thing we need to watch out for,” he notes.

Heat pump units are going to add a half a ton of cooling to the space, Ariano notes. “You can duct it somewhere, which is fine in the wintertime if you install it in a room with a furnace or boiler, which is going to absorb some of that heat. But in the summertime, it is going to make basements — or wherever the unit happens to be located — colder,” he says.

Poust also installs a lot of 75-gal. natural gas water heaters; homeowners replacing a water heater over 55 gal. will be forced to switch over to a condensing water heater, he adds. Standard storage tank condensing water heaters are available, but Poust believes that many homeowners may look toward tankless water heaters.

Tankless water heaters already meet the new water heater energy-efficiency regulations, but they may not be the best solution in all situations. In certain parts of the country, plumbers may have venting issues with tankless water heaters.

“In the Midwest and in the North where your incoming cold water temperature is so much colder, there are sizing issues with tankless water heaters,” Ariano explains. “A pretty big cost is associated with changing over from a tank style to a tankless. Most water heaters in our area are in the basement and venting to a chimney. If you go with tankless, you have to run a direct vent, either through high-grade stainless-steel material, which is expensive, or you go with a high-efficiency condensing tankless water heater that can use PVC.”

Local codes will have an impact on venting for replacement water heaters no matter where you live.

“Many modulating condensing water heaters are PVC-vented, so we can’t put the exhaust into a regular chimney because the acidity from the flue gasses will eat away at the actual chimney, so we need to determine if they should be lined,” Poust says. “If they’re PVC-vented,  there may be restrictions on where the new vent is going to terminate. I know a lot of local codes dictate that the condensate is to be run through an acid neutralizer so that it doesn’t affect the sanitary sewer.”

Regardless of what type of replacement water heater a homeowner chooses, after April 16 it is going to cost him more money.

“The process of replacing an older storage tank unit will be more expensive and often more complicated than in the past, particularly if the new larger tank size presents contractors with a challenge when installing the unit,” Kidd says. “Each individual situation is unique, and contractors should educate themselves so they can to provide the advice and insight homeowners need to make informed decisions.”

Poust notes that switching from an electric model to a heat pump water heater may include electrical modifications, and switching from a standard gas-fired water heater to a modulating condensing model may require upgrading the gas line from 1/2 in. or 3/4 in. to 1 1/4 in. or 1 1/2 in.

In order to give clients the best information about replacing their water heater system, plumbing contractors need to do their homework and be prepared.

“Contractors need to go to their manufacturers and do the research to find out how much larger these units are going to become,” Ariano notes. Many manufacturers are providing factory or on-site training on their products, as well as information on their websites.

Poust recommends partnering with a good distributor. “Many supply houses are offering classes, so I would definitely recommend you get together with your vendors and make sure you have your technicians trained, so that when they go out to someone’s house, they know what’s going on and can explain it to the homeowner,” he says.