Installing water heater

[sneuman]

I am installing a 4-gallon electric water heater which I would like to feed the galley and head sinks, plus shower. If I install it aft (near galley), am I likely to have any problem getting hot water 20' forward to the shower (which is the main reason I want the heater in the first place). The reason I ask is that the heater fits nicely near the galley, but not so nicely nearer the head.

BTW, it's an Ariston brand that I bought from Home Depot.

[Vasco]

Should not be a problem if properly installed with a good pump. On my CS36M the tank is way aft next to the rudder shat and the shower is forward works well even though when I replaced the pump I put a lesser flow one in.

[curlew32]

The only issue is that you will waste water while waiting for the hot water to appear at the tap. There is quite a bit of water in 20 feed of hose, so if you use a lot of hot water, you can waste quite a bit each time you run the water waiting for the hot water to appear. some people plumb in a y valve, with one end going back to the top of the water tank, so the cold water in the hose is preserved.

[Vasco]

When we've been motoring and have a hot water shower we run the cold into a jug first so as not to waste water.

[S/V Antares]

Neet looking unit. So this will be shore side only or do you have a genset?

[GordMay]

A 20 Foot length of ½" inside diameter pipe/hose will hold approximately 0.204 US Gallons (or about 28 ounces) of water - which represents about 5% of your 4 Gal. water heater capacity.
As noted, the standing water in your HWS (Hot Water Supply) pipes will quickly cool, after having been heated. This represents wasted heating energy, and unless utilized, wasted water.

[sneuman]

agreed, but the only other option is to install it amidship under a side berth, but that would involve a fair amount of re-routing of plumbing.

[sneuman]

Originally Posted by S/V Antares

Neet looking unit. So this will be shore side only or do you have a genset?

shore-side only. i thought about a gas/electric, but from my research it looks like you'd still need 120v to ignite the propane. That sort of defeats the purpose.

[GordMay]

Insulate the HWS pipe/hose, to minimize the heat loss.

[David M]

We are talking such a small amount of water loss and heat loss compared to what is available, that I would not worry about either. There is maybe a foot or two of pressure head and any loss in flow will be from friction. Your better off placing the water heater where it is most convenient and running the hot water hose to the shower and head sink. What I am wondering is how well is your hot water heater meant for a home environment going to hold up in a marine environment?

There are also on demand hot water heaters which heat at the water outlet. No water heater is necessary with these.
Ariston GL-8 Electric Mini-Tank Point-of-Use Hot Water Heater

Hot Water Heater - More Categories - Compare Prices, Reviews and Buy at NexTag - Price - Review

A third option is to get a water heater that can use both electricity or waste heat from your generator or propulsion engine like this one: Atwood Marine - Boat Water Heater from the Boat Water Heater Source

[sneuman]

[quote=David M;110388]We are talking such a small amount of water loss and heat loss compared to what is available, that I would not worry about either. There is maybe a foot or two of pressure head and any loss in flow will be from friction. Your better off placing the water heater where it is most convenient and running the hot water hose to the shower and head sink. What I am wondering is how well is your hot water heater meant for a home environment going to hold up in a marine environment?

There are also on demand hot water heaters which heat at the water outlet. No water heater is necessary with these.
Ariston GL-8 Electric Mini-Tank Point-of-Use Hot Water Heater

Actually, the one I've purchased is a 4-gallon version of the one above.

[sneuman]

I installed the Ariston this weekend. Works great, but 4 gallons ain't much - just enough for a quick shower, but that's all I really wanted anyway.

The unit, from Home Depot, is an Ariston. Very compact and easy to install, and at $150, can't beat the price!

[GordMay]

Originally Posted by sneuman

...Works great, but 4 gallons ain't much - just enough for a quick shower, but that's all I really wanted anyway...

Sounds like you need to take “cool” Naval Showers*, under a Low-Flow shower head.

Low-flow shower heads (<2.5 gpm) and faucet aerators can reduce your water consumption & heating cost as much as 50% (same pressure but reduced volume).

Naval Showers typically use about 4-5 gallons of water total (or less). Cool showers use < 50% Hot water (by volume), hence reducing Hot water consumption to under 2 Gal.

1. turn on the water
2. immediately wet the body
3. turn off the water
4. soap up and scrub
5. turn the water back on, and rinse off the soap
6. turn off the water

[Morgan Paul]

Hey Gord is that the same as a so called "Military Shower"?

[sneuman]

Originally Posted by GordMay

Sounds like you need to take “cool” Naval Showers*, under a Low-Flow shower head.

Low-flow shower heads (<2.5 gpm) and faucet aerators can reduce your water consumption & heating cost as much as 50% (same pressure but reduced volume).

Naval Showers typically use about 4-5 gallons of water total (or less). Cool showers use < 50% Hot water (by volume), hence reducing Hot water consumption to under 2 Gal.

1. turn on the water
2. immediately wet the body
3. turn off the water
4. soap up and scrub
5. turn the water back on, and rinse off the soap
6. turn off the water

yep, just enough hot water for that!