Differences Between On-Demand and Conventional Water Heaters

Deciding on a new water heater can be about as difficult and confusing as buying a new car.  Decisions, decisions, decisions… Now that we’ve talked it up and terrified you, allow us to contradict ourselves.  There are basically two types of water heaters:

·         On-demand water heaters (also known tankless water heaters)

·         Conventional water heaters (also known as traditional water heaters)

Like most purchases, there will always be trade-offs.  To help you make a sound decision, we’ll break down your options:


Conventional water heaters

 A conventional water heater stores and pre-heats about 30-50 gallons of water in a tank. The heater usually maintains the water at a temperature between 110-140 degrees. This pre-heated water is used for showering, doing laundry, washing dishes, etc.  As the water is used, the tank refills and begins heating the new supply of water.

 The ol’ industry standard.  These water heaters have been around for quite a long time.  In fact, conventional water heaters used to be synonymous with the term water heater (like Coke = Coke...don’t bring your Pepsi around here…we can debate this in a different blog post if you’d like). As such, its heating/burner element is regularly cycled on and off, as required to maintain the water’s temperature.

Conventional water heaters are larger than tankless water heaters and tend to offer better flow rates as well as higher temperatures. On the other hand, once all the hot water gets used up, you will need to wait for another store of water to be heated again.  Cue the inevitable screaming and crying when the last one out of bed is facing the dreaded cold shower after the rest of the family “used up all the hot water”. 


On-demand water heater

Just like the on-demand name suggests (they keep terms simple for us plumbers), an on-demand water heater does not store hot water in a tank but instead heats water as needed. On-demand water heaters are much smaller in size than conventional water heaters and take up much less floor space.  Oh, and many can fulfill the dream of endless hot water.  Say it with me, endless hot water.  Ok, maybe us plumbers are the only ones who have those dreams.  Moving on.

So how do they work?  A tankless or on-demand water heater is just that: tankless. It’s a smaller wall-mounted rectangular box that houses a heating element or burner, internal piping and controls. As water channels through the water heater to meet the demand, its water flow sensor activates and fires the heating or burner element.  Since they offer hot water on demand, they are considered a more economical choice because they aren’t constantly fighting ambient temperatures to maintain a tank of water at a particular temperature.  And there’s no pilot light (small but mentionable energy cost).  AND they have a longer life expectancy.  AND AND they cost less to maintain (on average). 

It sounds like we are trying to convince you to buy an on-demand water heater, doesn’t it?  There’s a catch...there’s always a catch.  On-demand heaters normally come with a little higher price tag.


Well, which should I buy then?

 According to Energy.gov, an on-demand water heater can save you close to $100 annually. Therefore, if you can manage the higher initial costs, you can save much more in the long run by switching to an on-demand water heater. In addition, on-demand water heaters can be the best choice for large families since you have more people requiring hot water. Still, a conventional water heater will make sense if you are on a limited income or require a quick replacement and you don’t mind giving up the floor space.

We love both water heaters equally (we’re forced to say that about our children).  On-demand heaters have quite a few advantages: lower utility costs, constant hot water, a longer lifespan and they take up less space.  Conventional water heaters are cheaper upfront, usually provide adequate hot water for most families and will get the job done (they’ve been our go-to for many years).

Ultimately, you want a water heater that fits your budget, lifestyle, and water usage. The choice is yours, but the expertise is ours (yeah, we said it)!  We’re here when you need us! Email at INFO@ROCKSOLIDPLUMBING.COM or call us at 907-331-0488.