550-EC NG Natural Gas Tankless Water Heater

The 550-EC NG is a four-season, tankless water heater, installing and fluing just like a tank type water heater, through the sidewall.
  • Endless hot water. Never run out.
  • Specifically for sidewall installations in RVs, Buses, Tiny Houses, Barns, and more
  • Standard cold weather protection
  • Dimensions 13.5”wide X 14.25” high X 13.5” deep and weighs only 32 pounds
  • Precise electronic VariFlame temperature control system
  • No pilot light and very high efficiency
  • Fully certified to ANSI Z21.10.3/CSA 4.3 standards
  • High output. 55,000 BTU max input (88 degrees F temperature rise/gal/minute)
  • Door included (Choice white, black, or aluminum)
  • Install video below

Price: $1,350

550-EC NG with White, aluminum door

550-EC NG with Black, aluminum door

550-EC NG with UNPAINTED, aluminum door (great for airstream)*

*This door is made from unfinished aluminum. Some scratches and imperfections may be seen. Unpainted door may require buffing or refinishing to meet your application.

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  Hot Water in Any Season

The PrecisionTemp 550-EC NG tankless, water heater utilizes our patented VariFlame Control technology to deliver an endless flow of hot water for the ultimate shower.

Whether in the dead of winter in the North Dakota oil fields or on sunny days in southern Florida, hot water is there for your enjoyment.

  The Proof is in the POWER

With 55,000 BTUs—the highest hot water output in the industry—and built-in freeze protection, the 550-EC NG delivers 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 flow rate or incoming water temperature.

  More Hot Water. Less Natural Gas.

With higher efficiency and 55,000 BTUs, the 550-EC NG produces more hot water than traditional water heaters.

Without a tank to keep hot, many people report that they use up to 50% less natural gas. Owners love the lower operating costs and fewer fill-ups.

Type:Tankless natural gas-fired water heater with full gas modulation. Power-vented sidewall penetration and cold weather protection.
Dimensions:13.5″ wide x 13.5″ deep x 14.25″ high
Weight:32 pounds
Capacity:55,000 BTUs max input (88°F temperature rise / gal / minute)
16,000 BTUs min input (26°F temperature rise / gal / minute)
Venting:Power-vented through front access door.
Construction:Galvanized case with perforated mounting flanges for original equipment or aftermarket sidewall penetration.
Access door is aluminum.
Head exchanger: Solid copper. Gas train: Stainless steel.
Fuel:Natural Gas
Water Temperature:Adjustable
Controls: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.

What makes the RV-550 special?

Continuous, endless, no-wait hot water for as long as you want. You can shower for an hour! Or longer…

How does the RV-550 provide continuous hot water?

The RV-550 has no tank. The water is heated as it flows through the copper tubing.

How do I get the RV-550 to make hot water?

Simply turn on a hot water faucet. A flow meter in the RV-550 is activated and the heater automatically comes on. When you turn off the faucet, the burner shuts down. There’s not even a pilot light — it uses a 12V current for the electronic ignition.

How long does it take to make hot water?

The RV-550 begins making hot water in seconds.

If endless hot water is such a good idea, why doesn’t everyone do it?

Most people don’t realize that they have an alternative to tank heaters. Once you use one, you will never want to use anything else!

Does the RV-550 install just like other water heaters?

Yes. The RV-550 installs and flues just like a tank heater. The RV-550 NSP installs just like a tank heater, but flues through the floor instead of the wall, using the included exhaust pipe. The water, gas and electrical hookups are the same type used on tank heaters.

Will the RV-550 fit into the same hole from my old water heater?

In almost all instances it will. The RV-550 is designed to replace most 10 gallon heaters without modifications. Cutout dimensions are 14.5″ high x 13.5″ wide x 13.5″ deep. Flanges are 17″ high x 17-5/8″ wide. To replace a six gallon heater, add 2.5” in height (up or down) to the sidewall cutout.

How long are the venting pipe(s) supplied?

The standard exhaust pipe is designed to go through a typical 1.5″ floor and elbow to the side, but we can provide the extension to go through a thicker floor, or you can get one at a local muffler shop. A PVC conduit can be used through your floor for combustion air.

Is the RV-550 as noisy as my current tank heater?

No. It is so quiet that the only way you know it is operating is that you have hot water!

When operating, does it create as hot an exhaust as my tank heater?

No. It is about 50% cooler. It will not scorch the side of your home.

Does the RV-550 use more natural gas than tank heaters?

To the contrary, the RV-550 is far more efficient. Plus, because there is no standby heat loss, you may find that you are using only half as much natural gas.

How do I winterize the RV-550?

Simply drain the RV-550 of water by blowing it out with air or running non-toxic antifreeze through the heater while winterizing the rest of your plumbing system. The RV-550 only requires about a pint of antifreeze.

Could you further describe the cold weather protection system on the RV-550 model?

The cold weather protection on the 550 series is standard. This feature will prevent freezing under most conditions. It has a built-in thermostat that turns the burner on in low burn when the heat exchanger temperature is about 38° F. At the same time, small 12 volt heaters protect the internal plumbing and control valve.

In order for this to function, the 12 VOLT AND GAS SUPPLY MUST REMAIN TURNED ON. This allows the burner to fire and electric elements to protect the system. Any freezing of the water heater or other plumbing components can cause severe damage that is not covered by warranty.

Unlike other tankless models, you don’t have to dump water on the ground or plumb it back into your water tank. This wastes water and natural gas. Our freeze protection uses very little natural gas and less than 2 amps of power.

Aren’t all “wetted” components in the heated living space of my home? Why do I need freeze protection?

The “wetted” components are technically inside, but the combustion air is drawn from the outside through an opening in the bottom of the unit. On the NSP model, the 2″ exhaust pipe also goes to the outside. This can allow freezing air to enter the unit.

Related Video:

How to install tankless PrecisionTemp water heater in RV Camper Travel Trailer 550-EC