Due to their efficiency and energy-saving features, tankless water heaters are becoming one of the most sought-after house appliances. That doesn’t come as a surprise, though; apart from saving you energy, money, and space, these devices provide endless hot water – whenever you need it. If you have considered buying a tankless water heater unit, you have probably faced the famous dilemma: a condensing vs non condensing tankless water heater.
If you aren’t a pro when it comes to water heaters, there’s no need to worry. I will explain the difference between these two types of tankless water heaters and help you make a sound decision based on facts alone. So, get ready to learn!
What Is Condensation?
The process during which vapor turns into liquid is called condensation. It happens when hot gas gets in contact with a cold surface. When it comes to tankless water heaters, due to the intense heat which increases the temperature of water in only a few seconds, water can turn into steam very quickly.

The heating process produces exhaust gases which, once they cool down, become liquid once again. The problem is that the acidity of the condensation is strong, and it can corrode the ventilation units.
Non-Condensing Tankless Water Heater Reviews

If you worry about corrosion, listen to this: non-condensing tankless water heaters have an exhausting system which vents the produced gas outside as soon as it is produced; that helps avoid corrosion. So, acidic condensation cannot affect inner components of the water heater. Thus, you can be sure that your ventilation units or network will stay in good condition for a long time.
There is a downside, though; as the energy that was used to turn liquid into gas is basically wasted (around 20% of the heat is wasted), the operational efficiency is rather low. What’s more, since the temperature may reach 300 F, non-condensing water heaters require specific venting materials. Specifically, venting units for this type of tankless water heaters have to be made of corrosion-resistant stainless steel, and they are generally expensive.
Condensing Tankless Water Heater Reviews
Here is how a condensing water heater works: once you turn on the switch, the process of heating water through combustion and gas burner beings. Then, exhaust gases are produced, and they actually contribute to the heating inside the unit since they produce additional heat. That’s why condensing water heaters are more efficient than the non-condensing ones; energy-efficiency is amazing, it can go up to 98%. In addition, cheaper ventilation materials can be used because the temperature of exhaust gases is around 100 F.How it Works – Rheem Condesning Tankless Water Heater
What about disadvantages? First of all, condensing water heaters are a bit bigger than the non-condensing ones, so you will need slightly more space for them. Secondly, these tankless water heaters are, by rule, more expensive to acquire and maintain. Depending on the type and quality of water in your area, your condensing unit will require professional maintenance at least once a year.
Pros and Cons
After carefully reviewing these two types of tankless water heaters, I decided to make things as easy as possible for future buyers and make a list of the most important things to consider for each type of these tankless units.
Non-Condensing Water Heaters
- Cheaper to buy
- Require minimal maintenance
- Take up less space than condensing heaters
- Lower energy-efficiency score
Condensing Water Heaters
- A more expensive initial price
- Cheaper to operate
- Amazing efficiency (up to 98%)
- Require regular maintenance
So, in the case of the condensing vs. non-condensing tankless water heater, have you decided which one is better for your needs?
Think About This Too
If you still haven’t made up your mind, don’t start panicking just yet. Maybe it isn’t just the dilemma concerning the condensing vs. non-condensing tankless water heater that is worrying you. Maybe you read multiple outdoor tankless water heater reviews or reviews on best propane tankless water heaters, and you simply feel overwhelmed.
I recommend that you take a step back and relax. Ask yourself if this new unit that you are planning on buying will help you conserve energy and make the most of its functionality. That is the most important question; you should start from there. Also, you should be ready to make an investment; a tankless water heater will cost you two to three times more than a traditional water heater would.
Still, don’t only think about the money you will spend on buying the unit. In the long run, you will be able to save money on electricity bills. Moreover, you will have an endless supply of hot water, whenever you need it. Finally, your home will become more eco-friendly.
Before you start looking at specific models, make sure that you have resolved the condensing vs. non-condensing tankless water heater dilemma. I also recommend having a professional check your home and tell you about the installation in more detail. Not only will that give you a peace of mind, but it will allow you to start making financial plans.