Electric water heater likely better choice than gas

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This article was published 11/02/2023 (949 days ago), so information in it may no longer be current.

Question: I changed over from a gas water heater to electric some years ago. It was done at the time that I replaced my gas furnace with a high efficiency unit. The advantages at that time were as outlined in your previous article. Since then, is there not an option to eliminate the chimney and vent the gas water heater in the same manner as the gas furnace is vented?

Robert H.

Answer: Replacing an older natural gas water heater with an electric unit makes the most sense, when upgrading to a high-efficiency furnace. It is the quickest and most cost-effective, in the short term, as well as most environmentally friendly. For those reasons, direct vent high-e water heaters are rarely seen in our area.

I frequently recommend an upgrade to a water heater powered by electricity, to my clients, when upgrading an older furnace. This is also discussed when the client is a potential buyer of a home which has a furnace over 15 years old. The typical life expectancy of the furnace, at 20 – 25 years, is often double that of its water heater counterpart.

If the furnace is really old it may be naturally aspirated with a vent hood connected directly to a metal flue. Very often, the older gas-fired water heater shares this flue by way of a separate, but connected, pipe above the water heater vent hood. That connection is one of the main reasons to switch to electricity for the power supply for a replacement tank. Because all new natural gas furnaces are direct-vent, high-e models, they will no longer need to use the old chimney for venting out the combustion products.

Switching to electricity for water heating, along with running a high-e furnace, will allow discontinued use of the old chimney. This will have the minor benefit of preventing natural heat loss through the old flue when the appliances are not in use, which may increase your heating costs. When the old flue is no longer required, it can be capped and air sealed at the top and bottom and remain unused.

To directly address your question, there are another couple of alternatives to a standard electric water heater, which will allow the same discontinuance of the older vent. You could replace your older naturally aspirated gas water heater with a high-e model, or a gas-fired on demand water heater. Those units do vent out directly through a PVC pipe, like the newer furnace, but have several issues which make them less desirable. Firstly, the additional vent pipe will have to be directed outside your basement. That will require drilling an additional hole or holes in your foundation or exterior wall. It will also require more ceiling space in the basement and area outside, where it exhausts. That will add some cost to installation, but may be similar to the cost for the circuit breaker and wiring installation for an electric model.

The main reason for ruling out the high-e or on demand water heaters is initial cost. Both those water heater units are considerably more expensive than either a standard gas-fired model or an electric tank. That additional cost may be recouped over time by the lower operating cost of natural gas vs electricity, but it will take several years for that to even out.

The final reason to install an electric water heater vs. natural gas is the environmental one. As we strive to reduce the carbon footprint of our homes in the future, to reduce harmful emissions that lead to climate change, eliminating any source of those pollutants is desirable.

Installing a direct-vent high efficiency water heater to replace an older one is possible, but not as practical as an electric unit. Electric water heaters are much less costly, easier to install, longer lasting, and emissions-free, which all adds up to a better overall choice for your home.

Ari Marantz is the owner of Trained Eye Home Inspection Ltd. and a Registered Home Inspector (RHI)(cahpi.ca). Questions can be emailed to the address below. Ari can be reached at 204-291-5358 or check out his website at trainedeye.ca.

trainedeye@iname.com