The 6 Pros and 4 Cons of Indirect Water Heaters

Indirect water heaters lately have taken the market by storm. And why not? It has a lot of advantages associated with it. It is one of the simplest forms of domestic water heating(DWH) system out there and highly efficient as well. 

So selecting an indirect water heater for your household hot water needs could be a good decision. But before finalizing such an investment which can cost thousands of dollars, it’s smart to move to take everything into the account. To understand its advantages and disadvantages. Especially with an indirect water heater, which, as good as it is, it’s not for every household. 

We will talk about the pros and cons but let’s first start with the basics. At least you should know how these heaters work. 

How do indirect water heaters work? 

Indirect water heaters are well-insulated storage tanks with multifold coils inside them. With the help of a boiler or furnace, such as a space heater, the hot fluid is passed through this coil. And the heat of the hot fluid is transferred to the cold water inside the tank from this coil. That’s why the name “indirect water heater”. Easy peasy! 

The pros and cons of indirect water heaters

Pro #1 More monthly savings on the energy bill

Indirect water heaters heat water from the heat generated by the space heating boilers. So that means almost the same amount of energy is being used for the dual purposes of water and space heating. There is no separate source of energy that’s being used to heat water. 

So that’s money you are saving on water heating every month. 

Con #1 Hard water is an issue with indirect water heaters

If you have hard water coming to your home then chances are heat transfer efficiency gets negatively affected. And then it will take a little longer to heat the water. 

Also, the sediments and minerals start to build up faster, and then you need more frequent maintenance. 

Pro #2 Indirect water heaters can run on any fuel-fired boiler or furnace. 

A boiler or furnace powered by any fuel source including natural gas, propane, oil, electricity, or even solar energy works just fine with indirect water heaters. There’s no specific need for this type of system. Whatever space heating system you may have installed at your home should work just fine with it. 

Con #2 You may require to upgrade your boiler

Now, this is situation-dependent. If it’s new construction then you will already have chosen a boiler with sufficient heat capacity as per contractors’ advice. 

But if you already have a boiler that you later connect with an indirect heater and your hot water demand is high then an upgrade will possibly be needed. With a smaller boiler, the heating capacity will drop and, you will have to wait more for water to get heated. 

Pro #3 Less maintenance, happy life

As mentioned before, indirect water heaters are some of the least complicated DWH systems. This also means there are fewer parts and a simpler system. There’s also no burner in the tank which minimizes the sediment buildup. 

So all in all, indirect water heaters are less of a headache for maintenance. 

Con #3 Eats up precious floor space

Compared to the traditional tank water heaters, indirect water heaters surely are comparatively somewhat small and save space. But if you compare them with tankless heaters that can be hung on the wall, then no! 

An indirect water heater takes 80% more space compared to a tankless water heater which then also depends on the size of the tank you choose. 

Pro #4 Indirect water heaters have a longer lifespan

Tradition storage tank goes through a lot of sediment buildup and structural damage and cracks due to constant heat and pressure buildup. But since indirect water heaters don’t have a gas burner or any other direct heat source in them, the pressure and thus damage is minimal. 

The structure remains healthy and fewer sediments means less corrosion. This helps indirect water heaters to last much longer. So such units can even last upto 20 to 30 years. 

Con #4 Not for smaller homes with less hot water need

Indirect water heaters are not suitable for everyone. If you have a small family that doesn’t use a lot of hot water then the hot water and energy will just get wasted sitting there in the tank. So if you are a family of 2-4, then the better option would be to invest in tankless water heaters. These are compact, space-saving, and energy-efficient. Here are the best electric tankless water heaters for your house. 

Pro #5 Lower upfront investment

Since indirect water heaters don’t have their own heat source, this means it doesn’t require their own fuel line or vent for flue gases as well. It only needs a boiler. This results in exponential savings on material and installation costs. And thus your overall upfront installation cost goes down. 

Pro #6 Faster recovery time, more available hot water

Indirect water heaters are known for their fast recovery time, meaning it heats the tank full of cold water much faster. Of course, it depends on the size of your boiler as well but usually, recovery is faster than traditional tank units. 

And then, since recovery is fast, it also means you have more available hot water to use for large families. 

Indirect water heater vs storage tank

Now that we have discussed the pros and cons of indirect water heaters, let’s talk in a brief about the difference between indirect and traditional storage-tank water heaters. A lot of people have confusion in this so I think it’s in everyone’s interest to touch on this topic. Also, learn about the pros and cons of tankless water heaters here.

Indirect water heater

So first of all, indirect water heaters are well-insulated tanks with a coil inside of them. The hot fluid via the boiler is passed through this coil to heat the water and that’s why it’s called an indirect water heater. 

There’s no heat source within the tank. Instead, it comes from an external source like a boiler or furnace. 

Indirect water heaters require no fuel or electric line and venting for flue gases. 

Installation is cheaper compared to a storage-tank water heater. 

Storage tank water heater

Storage tank water heaters have their own source of water heating either an electric heating element or gas burner that heats the water. 

It requires its own fuel line or electric source and venting for flue gases. 

Installation of the storage tanks is relatively expensive compared to indirect heaters. 

Is an indirect water heater worth it?

So the last piece of the puzzle that needs solving is if an indirect water heater even worth it? 

The answer to this is yes and also it depends. 

If you have a high-efficiency boiler that can efficiently provide an indirect water heater with hot fluid then it can be one of the cheapest forms of water heating systems for domestic needs. Not just it will save you money but will provide you with a large reservoir of hot water.