M550-EC Propane Tankless Water Heater

The M550-EC is perfect for the boater who doesn't want to leave the comforts of home behind when on the high seas.
  • Endless hot water, on-demand
  • Designed specifically for the marine environment
  • Weight 30.5
  • Dimensions 13.5” Wide x 13.5” deep x 14.5” High. The power vent is an additional 2 inches.
  • No pilot light for safety and insurable
  • Straightforward installation.
  • Reliable, proven VariFlame technology control system
  • Complies to ABYC recommendations as an attended appliance when installed per instructions

Price: $1,495

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ShowerMate M-550
Average rating:  
 2 reviews
by scott on ShowerMate M-550
Works great, too hot for shower.

This water heater has worked great for us for years. Used for years in Canada, and has worked for the last 4 years in Mexico. (only repair was to replace the igniter circuit). The only issue is that the water flow needed to keep it running is too low for the shower, so showers are too hot.

The only cure I have found is to run another tap while taking a shower to increase the flow, however that eats up our limited amount of fresh water.

New ones may have a lower flow cut-in, but the one we have is too high.

Water heater has performed as well as would be expected by the specs. Only when it was below freezing in Canada, water would be well warm, not really hot. . Very happy with its ability to heat water on demand.

Thank you for your review. Feel free to reach out to Ray, our service Manager and he will be happy to discuss any of your concerns. His phone number is 800-934-9690 Ext. 110.

by Scott on ShowerMate M-550

We have had this unit on a boat for years, we have been ocean sailing with it, so it has been jammed around pretty good and continues to work fine.

Thanks for giving us a review!! Remember we are always here for you if you ever if you ever need service or have any questions.

  Hot Water in Any Season

The PrecisionTemp M550-EC tankless, marine water heater utilizes our patented VariFlame Control technology to deliver an endless flow of hot water for the ultimate marine shower.

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.

  The Proof is in the POWER

With 55,000 BTUs—the highest hot water output in the industry—and built-in freeze protection, the M550-ECdelivers on-demand, continuous hot water—all without using engine or shore power.

  Quiet and Efficient

For the same amount of propane, the M550-EC produces more hot water than a traditional water heater.

Many people find that they use up to 50% less propane, with lower operating costs and fewer fill-ups. It’s lightweight, compact, efficient and installs almost anywhere.

Type:Gas instantaneous, power vented. Full gas modulation temperature control.
Dimensions:13.5″ Wide x 13.5″ Deep x 14.5″ High, including power vent.
Weight:30.5 pounds full.
Electric: 18-2 x 2′ lead. Gas: Brass 3/8″ flare inside case, rear accessible.
Water: 1/2″ OD copper tubing.
Brass compression to 1/2″ NPT elbow can be installed or as specified.
55,000 BTU input – 44,000 BTU output at maximum burn at 8.5 WCI manifold pressure.15,000 BTU input – 10,600 BTU output at low burn at 1.2 WCI manifold pressure.
(88°F temperature rise per gallon per minute continuous flow at high burn).
Fuel Consumption:2.55 lbs per hour at maximum input. (At 2 GPM of water, 20 lbs of propane will produce over 940 gallons of hot water).
Mounting:Floor mounted flanges (included)
Clearances:Zero clearance top (blower), bottom and sides. 2″ in back for hook-ups. Enough space in front to remove cover for service.
Venting:2” power vent with proofing switch. (2” stainless flex duct recommended to the outside, and can run up to 15′).
Modular: Three assemblies; gas, electronics and water. Burner: High primary air, 12 element, atmospheric type.
Aluminized steel body with stainless flame strips.
Heat exchanger: Copper fin tube type with wrap for cooling.
Electronics: Plug in, potted, works-in-a-drawer.
Burner and flue assembly are stainless steel.
Fuel:Propane at 11 WCI
Burner: 12 element high primary air, atmospheric type with stainless steel construction.
Orifices: Brass # 71 x 12.Gas Valve: Redundant solenoid with integral regulator.
Water Temperature:Adjustable
Mounting flanges included. Must be mounted in accordance with any applicable Coast Guard and ABYC recommendations. As an attended appliance.
Safety Features:
The M550-EC is pilotless. There is no flame unless water flow is sensed.Flame rectification: Gas valve shuts off in .8 of a second if there is a flame outage.
Redundant gas solenoid.
Electronic high temperature shut-off (2).
ECO high temperature shut off @ 165°F with manual reset.Pressure relief valve at 100 PSI.
Power vent must proof fluing before gas valve opens.
Due to continuous product improvement, PrecisionTemp reserves the right to change specifications at any time.