We don’t often give much thought to our water heaters—until they stop working, flood the basement, or give us that cold shower wake-up call that no amount of caffeine can fix.
If your current system is aging, inefficient, or just plain annoying, it might be time to consider switching to a demand-type water heater. Also known as a tankless water heater, this sleek, energy-efficient alternative is gaining popularity for a reason—or rather, a whole list of them.
Let’s explore why making the switch could be one of the best home upgrades you didn’t know you needed.
What Is a Demand-Type Water Heater, Anyway?
In the simplest terms, a demand-type water heater heats water only when you need it. Instead of continuously warming up and storing a big tank of water (whether you’re using it or not), it activates the moment you turn on the hot tap.
Here’s how it works: cold water flows into the unit when you demand hot water (see what they did there?), and it gets heated instantly via a gas burner or electric element. No tank. No waiting. No wasted energy. It’s hot water on demand, hence the name.
Why Consider a Demand-Type Water Heater?
1. Energy Efficiency That Pays Off
The biggest perk? Demand-type water heaters are significantly more energy efficient than traditional tank systems. Because they don’t maintain a full tank of hot water 24/7, they avoid the so-called “standby heat loss” that tanks are notorious for.
According to the U.S. Department of Energy, for homes using 41 gallons or less of hot water per day, a tankless system can be 24% to 34% more efficient. Even for larger households (86 gallons per day), demand-type heaters can still yield energy savings of 8% to 14%.
That kind of efficiency shows up on your utility bill. And over time, it adds up—especially if you live in a household where every shower is a 20-minute Broadway rehearsal.
2. Unlimited Hot Water (Almost)
This is one of the most beloved features of a demand-type water heater. As long as your unit is properly sized for your home’s needs, you’ll get a nearly endless stream of hot water. No more racing to the bathroom before the hot water runs out. No more sacrificing comfort because someone else took a long shower. Everyone wins—except maybe your water bill if you suddenly start living in the tub.
3. Space-Saving Design
Traditional water heaters are basically the washing machines of the water world—bulky and hard to hide. A demand-type water heater, on the other hand, is about the size of a carry-on suitcase and can be wall-mounted inside or even outdoors (depending on the model).
This frees up valuable floor space, which is especially great for smaller homes, apartments, or minimalist enthusiasts who want every square inch to count.
4. Longer Lifespan
Tankless units typically last 20 years or more, compared to 8–12 years for traditional water heaters. Yes, they often come with a higher upfront cost, but you’ll likely replace a tank water heater twice before you’d need to replace one demand-type unit. Think of it as the “buy it nice, or buy it twice” philosophy in action.
5. Cleaner Water, Fewer Surprises
Since there’s no storage tank for sediment to build up in, you often get cleaner water over time. Sediment buildup is one of the leading causes of wear-and-tear in traditional water heaters, leading to reduced efficiency and unpleasant surprises like rusty water or strange noises. A tankless system avoids most of that drama.
What’s the Catch?
Okay, no system is perfect. Here are a few things to keep in mind:
Upfront cost: Demand-type water heaters usually cost more to purchase and install than traditional tank systems. However, the long-term savings on energy bills and the longer lifespan can help balance this out.
Installation may require upgrades: If you’re switching from a conventional tank system, your home’s plumbing or electrical/gas system might need updates to handle the new unit.
Flow rate matters: Tankless systems can struggle to meet simultaneous high demand (e.g., shower + dishwasher + laundry all at once) unless you size your system correctly or install multiple units.
Is a Demand-Type Water Heater Right for You?
If you’re building a new home, remodeling, or your current water heater is on its last leg, it’s definitely worth considering a tankless upgrade. Especially if:
You value energy efficiency and lower utility bills.
You want unlimited hot water.
You’re tight on space.
You plan to stay in your home long-term.
For large households, pairing two units or opting for a high-capacity model may be the way to go. And always, always work with a licensed plumber or HVAC professional to determine the best setup for your needs.
A demand-type water heater might not be the flashiest home improvement you can make, but it’s certainly one of the smartest. It offers long-term energy savings, modern convenience, and that glorious hot water—whenever you want it.
Plus, it might just be the last water heater you buy for the next two decades. And that’s about as close to “set it and forget it” as home ownership gets.
Thinking about going tankless? Your water (and wallet) will thank you. Give the pros over at On Call Water Heaters a call today.
