Best Boiler For Radiant Floor Heating | Top 5 Picks

Let me tell you why your floor is not getting the heat that you need.

Maybe you’re not getting the hot water supply as you should. Maybe the water gets cold in the process.

Now don’t say ‘Hey, but I just got a new water boiler last month.’ Pfft! It doesn’t matter if you got a new one or an old one. The question is, ‘Have you got the best one?’

Well, to make sure your floor is getting the perfect heat, you should get yourself the best boiler for radiant floor heat.

Do you need a guide? I’m here to help you with that. Go through my reviews and choose the perfect water heater that meets your needs.

Best Boiler For Radiant Floor Heat

Can I Use Regular Water Heaters for Radiant Floor Heating?

Before you jump into the reviews and make your eyebrows go up, let me say to you ‘Do you know you can use hot water boilers to heat your radiant floors?’

Not ringing any bell, is it? The heaters that you want to use for your radiant floor will cost you a fortune.

Why waste your money when you have an alternative? Ask your neighbors, a lot of people have been using water heaters (the ones they use in the bathroom) as a radiant floor heater alternative.

If you know the process of using a hot water heater for radiant heat, who needs those expensive boilers? The regular water heaters will do your job.

Learn how to Use a Hot Water Heater for Radiant Heat

Top 5 Best Boilers for Radiant Floor Heating

Here are the top 5 boilers you can use for radiant floor heat. All these boilers are well-known for their amazing functionality and service quality. But it’s you who should be choosing the best one. Let’s see what I have got for you.

1. Rinnai V75IN Hot Tankless Water Boiler Natural Gas

Rinnai V75IN Hot Tankless Water Boiler Natural Gas

Rinnai V75IN HE Tankless Hot Water Boiler can be your best electric boiler for radiant floor heat if functionality matters to you.

The ergonomic design looks appealing, and you’ll have the premium feel as you take a look at this hot water boiler. People are craving for this boiler to get their job done when it comes to radiant floor heating.

You’re getting the ultimate performance with 18,0000 BTU and 7.5 GPM that you can ever expect from a water boiler. You may ask why 7.5 GPM is a big deal? You can check other water boilers; they’ll offer you 3.5 GPM at best.

Highlighted Features

  • Rinnai V75IN comes with 18,0000 BTU and 7.5 GPM, so getting hot water within seconds won’t be a problem.
  • You can control the temperature from 98 degrees Fahrenheit to 140 degrees Fahrenheit.
  • It has an eco-gas burner that eliminates NOx emission.
  • It can carry up to 1200 pounds of weight, so you get to store a lot of things in one go.
  • The scale control system prevents the boiler from suddenly breaking caused by an accumulation of scale.

The performance of this boiler is very well-optimized as it comes with a 0.82 energy factor. With the integrated temperature controller system, you get to set your temperature according to your desire, ranging from 98 degrees Fahrenheit to 140 degrees Fahrenheit.

Don’t forget the contribution of the clean combustion that you get from natural or propane gases that boosts up the overall performance of the boiler. It comes with an eco-gas burner that makes sure the NOx emission is low enough to be environment-friendly.

Team Rinnai cares about your safety, and therefore they included a scale control system inside this water boiler. Why? Well, boilers usually break due to an accumulation of scale. What worse, it happens suddenly.

This feature will save your water boiler from breaking when there’s the scale accumulation. As a result, your water boiler will survive years after years.

It also features a temperature-lock system to prevent breaches. Moreover, it has a frost protection system as well to make sure that water in the tube doesn’t spoil the tool.

There’s also an electronic ignition system to save the energy of the water boiler. So, the next time you ask why Rinnai V75IN can be your best radiant boiler, you better keep these features in mind.

2. Stiebel Eltron Tempra 29 Plus Tankless Water Heater

Stiebel Eltron Tempra 29 Plus Tankless Water Heater

The problem with typical water boilers is the temperature decreases with the increase of water flow. As a result, you don’t get to have the hot water you need. That is why you should go for something that controls the flow of water.

Tempra 29 Plus Stiebel Eltron Tankless Water Heater proudly presents an advanced flow control system that makes it one of a kind. The water boiler reduces the flow of water all by itself when it senses an increase in water flow.

Highlighted Features

  • The Advanced Flow Control system reduces the water-flow all by itself, and the water never turns cold.
  • The microprocessor technology always keeps a steady output temperature.
  • There’s no venting system in the product. As a result, the heat stays inside it while maintaining the hot state all the time.
  • With 4.37 GPM, a bulk amount of water gets hot very fast.

As a result, the water stays hot all the time and maintains its state. There’s no way it will turn colder while it’s on the operation.

However, let’s say you couldn’t escape the water-flow change. The temperature keeps changing while the boiler is in operation. Don’t worry, the microprocessor technology along with several temperatures and flow sensors got you covered.

Even if the flow rates change, this technology will make sure there’s always a steady output temperature. The exclusive Electronic Temperature Control, on the other hand, lets you set the knob on the front cover so that you can have your desired water temperature.

Most water boilers store hot water inside for later use. For this reason, you’re getting 15 to 20% less energy from them. Besides, since they use the venting process, they lose a lot of gas that eventually results in heat loss. As a result, you don’t get warm water when you need it.

Well, this water boiler doesn’t have any venting system. So, there’s no chance of losing the gas. The gas stays tightly packed inside the boiler, so the heat stays inside. Consequently, you get nothing but nice hot water-flow all the time.

Besides, when you have the 4.37 GPM and temperature reaches up to 125 degrees Fahrenheit, you’ll never feel the lack of hot water anymore.

3. Takagi TH3DVN Natural Gas Indoor Tankless Water Boiler

Takagi TH3DVN Natural Gas Indoor Tankless Water Boiler

My next pick is Takagi TH3DVN. This natural gas indoor tankless water boiler for radiant floor heating has been widely known to everyone as it touched the hearts of thousands with its service quality.

First off, you’ll love its functionality and how it keeps the water hot all the time. It’s a tankless water boiler comes with high energy and thermal efficiency.

With 19, 500 to 140,000 BTU range, you don’t have to worry a bit about getting nices warm water.

Highlighted Features

  • It comes with 19,500 to 140,000 BTU range. You can have hotter water compared to others.
  • It heats up to 10 gallons of water per minute. I think that more than enough.
  • You can cover more than three units with this heater.
  • The boiler gives you endless water-supply. There’s no chance of running out of water.

You’ll be able to heat up to 10 gallons per minute while most water boilers come with 2 to 3 GPM. It means, even if you need the hot water delivery as early as now, you can have it with this device.

The problem with most water boiler is you can’t connect them with more units. This water is an exception. You can connect this water boiler to different types of units.

It doesn’t matter if you’re using a multi-unit controller or not. You can cover more than three units with this beast around to deliver you hot water easily.

The problem with most water boilers with vents is that the gas gets out of the device. As a result, you get a lot of heat loss. And when there’s heat-loss, you can’t expect your water to get easily, can you?

Even though the heater has a vent, you’ll be surprised to see that the gas doesn’t get out of it at all. As a result, the heat always stays inside making your water boil with all everything it has.

Your floor might be really big, but you won’t be running out of the water any time soon with this device around. You’re getting endless hot water supply.

4. iHeat Tankless Stainless Steel Electric Water Heater

iHeat Tankless Stainless Steel Electric Water Heater

You can choose iHeat S-16 240V 66A tankless stainless steel water boiler as your best water heater for radiant floor heat. It comes at an affordable price, but it has a lot of things to offer you that even the expensive ones can’t afford.

First of all, you don’t have to worry about durability at all. iHeat tankless water boiler has got it all to survive for years to come. Thanks to its heavy-duty stainless-steel construction, it can survive even in all the tough conditions.

Highlighted Features

  • The heavy-duty stainless-steel construction enhances the durability of the boiler.
  • It comes with anti-rust and waterproof features. You can also control the temperature with the waterproof touchpad.
  • It has a very compact shape, so you can easily fit it almost anywhere.
  • It uses 99% of its energy and saves up to 60% of your energy cost.

Oh, did I forget to tell you it’s even water-proof? You didn’t expect it, did you? Well, from now on, you’ll be able to control the temperature safely, thanks to the water-proof interactive touchpad it comes with.

When I said ‘steel’, I won’t be surprised if the word ‘rust’ or ‘corrosion’ popped inside your head. I mean, come on, the last thing you probably would want is to see the water boiler gets rusts.

Well, the boiler comes with an anti-rust feature that prevents rust and corrosion. So, you can relax now.

Now I know you want to install this thing for radiant heating, but you can use it for a lot of other things as well. Yes, the water boiler offers you such versatility.

You can use it as a water boiler even in places like commercial kitchens, clinics, hospitals, schools, bathrooms, and of course, under your floor for radiant heating.

Unlike any other, this one comes in a very compact size. You can say goodbye to all those big water boilers that eat up too much of your space. This water boiler can fit almost anywhere that has space issues.

It makes use of 99% of its energy and saves up to 60% on your cost. Besides, heating your water fast won’t be a problem as it comes with a 3.5 GPM heating capacity.

5. EZ Ultra HE Natural Gas Condensing Tankless Water Heater

EZ Ultra HE Natural Gas Condensing Tankless Water Heater

EZ Natural Gas Condensing Tankless Water Boiler comes with a premium look and mind-blowing features that will surely impress you. When it comes to heating the water, of course, you want something that can do it efficiently.

This water boiler uses exhaust gas that heats the incoming water instantly. It reheats the inlet water which results in reducing water consumption. As a result, you get less energy bills as well.

It produces enough amount of hot water with 3.4 GPM that would be enough to help you with your radiant floor heating.

Highlighted Features

  • Since the boiler reheats the inlet water, the water-consumption is reduced to save energy bills.
  • If it remains inactive for a while when you forget to extinguish it, the heater automatically extinguishes itself.
  • You’ll be able to vent the unit both vertically and horizontally.
  • It comes with a compact shape. Fitting it anywhere won’t be a problem.

If you have memory issues and forget to extinguish your water boiler, you can count on this one. The boiler features a full-automatic operation. Even if you forget to extinguish it, EZ tankless water boiler will extinguish itself when it stays inactive.

You can vent this water boiler using 2″ Solid Core 40 PVC/CPVC. As it has a condensing heat exchanger, it captures and drains the acidic condensation. The best part is, you can vent the unit both vertically and horizontally. All you need to do is to use a 30 ft vent pipe.

Since the water boiler has a low water pressure ignition system, it will function at 8 PSI water pressure.

As a result, even if you’re someone who lives at high altitude or maybe you’re using well water with less pumping systems, this water boiler can get your job done easily.

The whole set comes with a very compact shape. Its slender body makes sure you can store this water heater almost anywhere, even if you have space issues.

Read: Beat Combi Boilers Reviews

Things to Consider Before Buying a Water Boiler for Radiant Floor Heating System

Now that you’ve decided to buy the best boiler for radiant floor heat, you can’t simply walk into the store and get yourself one. A big NO.

You must know what features you should look for before making the purchase. Don’t know what to look for? Well, here are things you should consider before buying a water boiler.

1. Material and Durability

The material the water boiler is made of, and the durability of the product is connected. How? Well, if the material is good, the product will survive in the long run.

You’ll find water boilers that are made of heavy-duty stainless steel. You can get your hands on such products. However, you have to make sure if they have an anti-rust feature or not. If they lack this feature, it won’t survive long.

2. GPM

The more the GPM, the faster your water will boil. Also, it means you can heat loads of water every minute.

For example, if your water boiler has got 3 GPM, it means the water boiler can heat up to 3 gallons of water per minute. If the GPM is 7, it means 7 gallons of water is getting hot every minute.

Going for at least 7 GPM is a wise decision, especially if you have a wide floor. For a small flooring system, you can choose 3.4 to 4 GPM.

3. How Much Energy Does It Use?

You really need to ask yourself if your present water boiler uses most of its energy or not. Otherwise, walk into the store and look for water boilers that use maximum energy.

How will you know? Well, the amount of energy the water boiler uses should be labeled on its body or the user guide. There are boilers out there in the market that use up to 99% of its energy. As a result, you get to save a lot of your energy costs.

4. Does it Reduce Water Flow?

Reducing the water-flow is a must, especially when it gets increased all by itself. If your water boiler can’t reduce the water-flow, soon you’ll see the water is getting colder.

Some well-known brands manufacture water boilers that can automatically reduce the water flow. I would get my hands on such a water boiler if I were you.

5. Try the Boiler with No Vent

If the water boiler you’re buying has got vent, the heat will get out of the boiler. As a result, the water won’t stay hot for long.

Try to get the ones that have no vent at all. The gas will stay tightly packed inside, making sure the water stays hot all the time.

Frequently Asked Questions

1. What vent pipe size should I use for Rinnai V75IN?

Ans. You’ll need a 3-1/2″ vent pipe.

2. Will Stiebel Eltron Tempra 29 Plus run properly with 1/2-inch water supply?

Ans. Of course, it will.

3. Does Takagi TH3DVN come with a built-in recirculation pump?

Ans. Unfortunately, it doesn’t come with a built-in recirculation pump.

4. Can I use the iHeat S-16 240V 66A tankless water boiler in a camper trailer?

Ans. Yes, all you need to do is install it inside. You’ll need a 70amps double pole breaker & a 6-2 wire.

5. Do all these products have a warranty offer?

Ans. Yes. However, you have to talk to your nearest seller about this matter.

What’s Now?

Well, that was it for the best boiler for radiant floor heat. I’ve introduced to you the hot-running products in the marketplace. If you really want to take your radiant floor heat to its perfection, you can choose one of these without thinking twice.