Boat Tankless hot water heaters


Boat Accessories - Electrical Products

You will have dockside water and power. Instant hot water no waste of water waiting for lines to clear of cold water- cheaper to replace- endless hot water if needed-longer lasting- no need of holding water in water tank.

Marine Tankless Water Heaters

Tankless hot water heaters

An electric tankless hot water tank for your boat

It's basically unlimited hot water and they are only about $150. They use 27 amps and are 110 power. It goes under the sink- otherwise it would make no sense putting it in the engine compartment- it's for instant hot water with no tank.

Looking into it and the fact is, if you're using shore water hookup, it could work, We haven't made the final decision yet but we don't need hot water except when doing dishes. If the bath house is up the hill from your boat.

Easier to use the Marina's showers than sardine into the head.

You would be using every bit of your power though so everything would need to be shut off (although the hot water tank uses quite a bit as well). Jury's still out but we're leaning on trying it and putting in an additional 30 amp Galvonic Isolator. If nothing else, If nothing else, You are building a topside cooking and bar area and want on demand hot water, may try it for that.

Promariner Prosafe Failsafe 30 Amp Galvanic Isolator

it's marine certified ProSafe FS 30 meets ISO 8846 and can be mounted within an boat engine compartment. Starters, relays, battery chargers etc etc under the engine compartment -You would not worry about this- that's why there are circuit breakers if you choose to put it in the same place.

Easily install unit and does not require a dedicated monitor ProSafe FS 30 water heater is built on robust semiconductor FlatPack platforms ensuring that in the event of a failure the failure is safe on board.

30 Amp marine certified Tankless hot water heater

It really depends on the age of the boat but if you're not hooked up to dockside water, I wouldn't even consider it, but if you have the pressure of dockside water, it's a though. Just make sure you spend the money on a Galvonic Isolator, it does a couple of things, first off, makes your boat safer without having AC leaks around the boat and 2, saves (well slows the process) of your sacrificial anodes.

Savings for electricity - The Math

The average hot shower is 105ºF. Starting from a cold water temp of 60º we need a 45º temperature rise. Home showers run 2 GPM but we'll cut that in half on the boat to a much lower flow rate of 1 GPM.

1 kW/hr = 3412 BTU/hr and a BTU is the amount of heat necessary to raise one pound of water 1ºF.


1 GPM * 45º temp rise * 8 pounds/gal = 360 BTU/min or 21,600 BTU/hr divided by 3412 BTU per kW = 6.3 kW/h

6.3 kW/hr means you need 53 amps at 120 VAC.

On the other hand, when I'm away from the dock, the port engine's waste heat warms the water in the tank to 170º. A thermostatic mixing valve keeps the output at a reasonable 120ºF, which has the added benefit of making the hot water in the tank last much longer. There's no utilization of waste engine heat with one of those tankless units.

Hubbell Marine Heaters

Did you know that Company Hubbell manufactures water heaters specifically for Naval and marine applications. In add to water heaters fabrications they offer boat owners Tankless Water Heater model MHX/MTX.

Tankless Marine Water Heater MHX/MTX

 Tankless Water Heater by Hubell

Water Heaters compact model MHX/MTX are available up to 54 KW Single or Three Phase Voltages. MHX/MTX s a highly reliable and easily maintained Tankless heater specially constructed for marine applications and boat owners that they can rely on the Hubbell Tankless Heaters for their water needs a daily basis on board.

Water Heater Overview

Element Models shown

Marine (ABS) Type Approved, the Hubbell Tankless Water Heater units are heavy duty construction with high grade materials to ensure long operating life suitable for boats and yachts.

On demand heating eliminates cumbersome and costly storage water tanks Instantaneous design reduces stand-by heat loss and lowers operating costs.

The MTX electric tankless water heater is eqquiped with quality high powered heating, temperature controller and in flow sensor that measures the exact flow rate.

Water Heaters