It seems like a day doesn’t go by that a homeowner is calling asking about instantaneous, or tankless water heaters. Many of those callers think they’re substantially more energy-efficient than tank-type water heaters. Usually, they’ve heard or read about how much better they are than tank-type water heaters since they heat water only when it’s needed and thus there are no standby energy losses.
The trouble is…it’s NOT completely true. In a few situations, they can be okay, but not by any means are they usually the best solution. Let me explain.
Investment
The sad fact is it’s hard to cheat the gas company. If you heat water, gas is going to be burned and it’s going to cost the same to heat a given amount of water, no matter whether you do it with a tankless or with a tank-type water heater.
The total installation cost of a tankless water heater is typically four to five times higher than tank-type water heaters.
Here’s why. A typical residential tank-type heater is rated at about 40,000 Btu. To get the equivalent from a tankless, it’s often necessary to use a 160,000-Btu or even higher rated tankless. A tankless of that size will also need a larger diameter gas line supply from the meter which will add considerable costs to a tankless heater installation.
The costs of adding a flue must also be considered. For example, a standard tank-type 40,000 Btu water heater uses a 3 inch flue or it might even be vented together with a gas furnace. In either case a tankless will be more expensive to vent because their flue requirements are more stringent.
And finally, because of the bells and whistles that are incorporated into tankless water heaters, it’ll require 110 volts. Hiring a electrical contractor to run electric to the tankless location will add to the costs.
When you compare the installation cost between the two, it’s easy to see why it would take you a very long time to pay the difference between a tankless and a tank-type water heater.
Consistency
With a tank-type water heater, it’s possible to wash the dishes and take a hot shower at the same time. Or do two or three other hot water tasks simultaneously. With tankless heaters, it’s downright difficult to do two or more things at once.
Beyond that, temperature fluctuations can make taking a hot shower an ordeal. Water temperature can cycle from five degrees too cold, to just right, to five degrees too hot. Adding a small storage tank can resolve some of these problems, but tankless manufactures frown on storage tanks because it reduces the life of their tankless.
Here in the Reno/Sparks area, the temperature of the water can vary drastically from summer to winter. It’s not uncommon for the incoming cold water temperature to be around 45ºF or less in the middle of winter. Extreme cold water will push a tankless water heater beyond its limit in a typical residential setting.
Dependability
A typical tankless water heater has a flow valve that controls the burner when you demand hot water, plus a circuit board that lights the pilot, and switches that control the water temperature. As a 30 year old service company we have found that the more complicated the equipment, the more that will go wrong, resulting in high upkeep costs. Here’s what I mean…a typical service ticket on a tank-type water heater runs about $100. On a tankless, a service ticket can be about three to four times that amount. Upkeep costs must be factored unto the tank – vs. - tankless equation as well.
Here’s something else. The parts needed to repair a broken tankless water heater are not always available. It is our experience that it’s common to wait several days for parts, and the older the tankless, the longer the wait. In hard water areas – like here in the Reno/Sparks area — tankless water heaters are prone to “lime up” which seriously affects their efficiency. With tank-type water heaters, the minerals in hard water settle to the bottom where they can be more easily flushed out.
Contact the air experts at Nevada Heating, Air Conditioning & Plumbing. Ask our tech, request a service or offer feedback, please.
