PrecisionTemp RV-550NSP EC Floor Vented Water Heater


PrecisionTemp RV-550NSP EC Floor Vented Water Heater

Product Code: VTS-943


This is our favorite water heater for many vintage trailer installations.  It allows for an entirely hidden tankless gas water heater.  You can mount it almost anywhere in the trailer and have no sidewall venting.  It vents straight down through the floor using any 2" auto exhaust vent you want.  

Precisiontemp is known for having the best technology and reliability in tankless heaters.  The premium price repays you with dependability and intuitive operation.


  • Endless hot water - never run out.
  • Propane fueled. 12V required for ignition.
  • Specifically for installations in RVs, buses, tiny houses, barns, and more.
  • Standard cold weather protection built in.
  • Conveniently vents through the floor rather than through your sidewall.  That means a clean look that isn't visible from the outside. 
  • Straightforward installation.
  • Precise, best-in-class, electronic VariFlame temperature control system. 
  • No pilot light and 35% higher efficiency. 
  • Fully certified to ANSI Z21.10.3/CSA 4.3 standards
  • 13.5”wide
  • 14.25” high
  • 13.5” deep
  • weighs only 26.5 pounds


precisiontemp1.png   Hot Water for Your Trailer in Any Season

The PrecisionTemp RV-550 NSP EC tankless water heater utilizes PrecisionTemp's patented VariFlame Control technology to deliver an endless flow of hot water for the ultimate in pampering for you and your family while on the road or at home. No more waiting for a small water tank to refill and no more quick, cold showers.  Whether you're just one person or a whole family, endless hot water is available for your enjoyment.

precisiontemp2.png   No Sidewall Penetration

The RV-550 NSP EC is vented through the floor and out of the trailer or motorhome with a standard 2" diameter automotive exhaust pipe.  No sidewall penetration (NSP) means you don't have to cut a large opening in the wall.  It provides a sleek look you can't get with any other propane water heater.

precisiontemp3.png    Ultimate Floor Plan Flexibility

With a smaller footprint and floor venting, the RV-550 NSP EC allows for floor plan flexibility like never before.  You can place it anywhere in the living space, not just along the sidewall. This can free up cabinet space and provide a solution when trying to plan for every appliance, fixture and piece of furniture in a compact travel trailer or motorhome.

precisiontemp4.png    The Proof is in the POWER

With 55,000 BTUs--the highest hot water output in the industry--and built-in freeze protection, the RV-550 NSP EC delivers true on-demand, continuous hot water. The heater operates only when the hot water outlet is turned on.  The VariFlame control system then keeps the water temperature constant, regardless of the incoming water temperature or the rate of flow you have determined.

precisiontemp5.png    More Hot Water.  Less Propane.

With higher efficiency and 55,000 BTUs, the RV-550 NSP EC produces more hot water than traditional water heaters. Without a tank to keep warm and continually reheat, many people report they use up to 50% less propane.  Vintage trailer owners love few fill-ups and lower costs.


Installation Instructions for the PrecisionTemp RV-550 NSP EC




Tankless propane-fired water heater with full gas modulation. Vented through the floor with cold weather protection.


13.5″ wide x 13.5″ deep x 14.25″ high


26.5 pounds


44 BTUs per hour


Through the floor by 2″ exhaust pipe, power vented. Pipe not included. Use a standard automotive exhaust vent suitable for your installation.


Head exchanger: Solid copper.

Gas train: Stainless flame strips with aluminized steel bodies.



Water Temperature:



Gas modulation valve assembly initiates spark ignition and varies gas input based on water flow rate, controlling water outlet temperature.

Safety Features:

Pilotless ignition, completely dormant until water flow is initiated.

ECO high temperature limit switch.

Instant flame-proofing by flame rectification.

Pressure relief valve. Certified to ANSI Z21.10.3 / CSA 4.3 Standards.


Due to continuous product improvement, PrecisionTemp reserves the right to change specifications at any time.




Frequently Asked Questions:
Q.  What does EC stand for?
A.  Electronic control.  Not only does the EC control temperature by monitoring water flow, but it also looks at temperature variations and the computer quickly makes updates.  It improves the performance, especially in marginal water flow situations, resulting in better performance all the way around.
Q. How much propane does it consume?
A. In practical terms, one pound of propane can provide enough fuel for approximately 30 to 40 minutes of hot showers.  That's assuming 60F incoming water and a 1.5 gpm shower head.
Q. How long are the pipes for venting and combustion air?
A. The supplied exhaust pipe goes down and then elbows to the side.  It can pass through a floor as thick as 1-1/2" before elbowing.  A PVC conduit can be used through your floor for combustion air.
Q. Does the heat output modulate?
A. Yes, the water heater modulates based on water flow. With less water passing through it, the flame will be smaller so as not to overheat the water. You will mix hot and cold at the shower just like at home. The maximum temperature rise will be 88 degrees above the temperature of the incoming water. This can be achieved at 1 GPM. At 1.5 GPM, it can raise the temperature by 66 degrees.

Q. How warm will my shower be?
A. A typical shower in an RV or tiny home has a maximum flow rate of 1.5 GPM. Standard shower temperature is 105 degrees. The heater can warm 1.5 GPM flow by up to 66 degrees. So as long as your incoming water is at least 39 degrees, you'll achieve that 105 degrees at the flow of 1.5 GPM.

Q. What is the minimum temperature possible?
A. 33 degrees. Lower than that is ice.

Q. How many gallons per minute can the water heater output?
A. There is no maximum output.

Q. Does the water heater need minimum water pressure?
A. No minimum water pressure is required. But it does need a gallon of water to fill the heater before it will start. If the water is not moving or is not in the heater, it stops heating.

Q. How do I winterize the RV-550 NSP EC? 
A.  Simply drain the water heater by blowing it out with air or running non-toxic antifreeze through it while winterizing the rest of your travel trailer. It requires only about 1 cup of antifreeze. 
Description Above Price
  • PrecisionTemp water heaters ship to the contiguous 48 United States for $47.