Rinnai RL94eP Propane Tankless Water Heater Review

What's the best propane tankless water heater on the market?

As an HVAC specialist, this is a question I've been asked many times, and my honest answer is "it depends." Where do you live? How much do you care about energy efficiency? How many bathrooms does your water heater need to serve?

Speaking very broadly, I can say that the Rinnai RL94eP is my go-to recommendation for a tankless water heater. It's versatile enough to handle everything from mobile homes to high-rise offices, and it's also easy to install even for newcomers to the tankless water heater world.

It is a propane system, so you'll need to keep an eye on the flame, but it doesn't require any more maintenance than a gas-powered stove.

All in all, the RL94eP is a strong and effective unit that will suit many properties, and that's why it gets my seal of approval. But you don't have to take my word for it.

Let's look at the RL94eP in more detail.


Here are just a few important numbers for the RL94eP:

  • Flow rate: This unit can deliver up to 9.4 gallons per minute (GPM) depending on where you live and how cold it is outside. In moderate temperatures, you'll get the full 9.4 GPM; in extremely cold climates, your GPM might be a little less.
  • Power: The RL94eP requires up to 199,000 BTUs. It also has an 83 percent thermal efficiency.
  • Size: Good news if you're looking for a small unit! The RL94eP clocks in at just 46 pounds, which isn't the most compact on the market, but it's still light and portable enough for most homeowners.
  • Temperature: The maximum temperature for residential use is 140°F; the max temperature in commercial settings is 185°F.


As a propane unit, the RL94eP works through a system of internal sensors and heat exchangers. The burner uses a live flame. This makes it a very powerful tankless water heater that can service multiple bathrooms at once.

How many bathrooms, you may ask? That depends on how you're using the unit.

Sinks are nothing; you can turn on every tap in your home and the RL94eP won't break a sweat. Taking a shower and filling the tub are also okay. You can run your dishwasher while soaping your hair and never give it another thought.

When your demands get more extreme, however, you might need to be a little pickier about using your unit.

For example, you might experience flow delays if you're running your washing machine and dryer and hot tub all at the same time.

Don't be afraid to experiment with the RL94eP. See exactly how hard you can push it.

Heat Output and Flow

As previously mentioned, the flow rate of the RL94eP will depend on where you live.

Generally speaking, you can expect at least 4-5 GPM even in the coldest of climates, and the 9.4 GPM will be yours if you live somewhere more moderate.

Here are the exact specifications of your temperature controls:

  • In residential settings, you'll enjoy 98°F - 140°F.
  • In commercial settings, you'll receive 98°F - 185°F.

Please note that the commercial temperature range can only be "unlocked" with a special commercial temperature controller.

You'll need to purchase it separately if you want to use the RL94eP in your corporate building.


The installation of the RL94eP is fairly simple, though you might want to take care with where you install it.

While it can be mounted on both interior and exterior walls, the venting system needs to be exposed to fresh air, and there needs to be some kind of protection from the elements since the RL94eP can't get wet.

Here are just a few of the tools you might need to install this unit:

  • Ground lines
  • Circuit breakers
  • Electrical box
  • Vents

There are a number of valves, including isolation valves and relief pressure valves, that come included with the unit, so you won't need to worry about those.

If you have any questions regarding the installation of your RL94eP, talk to a trained Rinnai technician.

General Use

Like any tankless water heater, the RL94eP has both advantages and disadvantages. You should carefully weigh all of them before making your final purchase decision.


  • Powerful propane unit that can service multiple bathrooms at once
  • Can be used in both residential and commercial settings
  • Has an extended warranty covering parts, labor and installation


  • Requires venting system
  • Flow rate might change depending on outdoor weather
  • Not the most affordable model on the market

What's the bottom line?

If I had to rank the RL94eP, I'd give it four out of five stars. It isn't a flawless unit, and the performance you get out of it might vary depending on where you live and how you use it, but it's a solid and efficient unit overall.

Check out its reviews on Amazon to see for yourself how much customers love it!

Image credits: Rinnai

Also read: 

Enable registration in settings - general
Compare items
  • Total (0)