Hot Water

[williamsburg]

I hope I am in the correct forum. Anyway, I just hooked up a 2.5 gal. water heater to my CD22 and it works so well that I had to share it. It is installed under the sink - takes little room - and produces hot water in minutes. If you leave the dock the water stays hot overnight. And, most important it made the spouse happy. I have a schematic and photos and a shopping list with prices on my web site:
http://members.cox.net/rlampert3/index.html
May hook up an a shower on the back deck next.

The work was done by an all-thumbs geriatric clutz, so anyone interested can do it.

[lloyds]

Nice job. I have never seen a Ariston before.

[Adeline]

Congratulations on a first-rate installation! I believe you're the first 22' that has done this.

[Papillon]

Great Job

Now I have to make sure Judy doesn't see this, or I will be wearing a plumber jeans, butt crack and all.

But on the other hand, a hot water shower after a winter dive sure would be nice.

[JamesTXSD]

In most circumstances on the boat, 2.5 gallons would be great (just don't let a teenager at the waterpump). Nice job on the install, and a shower outlet in the cockpit would be a great addition on the 22.

[Falco]

williamsburg:

Very cool. I note from the web site you provided that the Ariston features "Italian Styling". This is almost as important as the hot water.

Ever thought about putting a GFI outlet in that recepticle rather than a standard outlet?

Also, can't tell from the pics, but you might want to put a check valve between the tank and the cold water inlet to ensure the tank remains filled as the water tank drains and also to ensure any unusual pressure escapes only via the pressure relief valve I see you have installed.

You might want to check with the manufacturer/distributor or a reputable marine appliance shop to see whether the unit should be bonded (connected to the boat's ground) to prevent it from galvanic corrosion. This might be taken care of if your AC circuit is bonded. I don't know so this is why you might want to seek solid advice.

When does the hot tub get installed?

[Byrdman]

real sweet!!

[williamsburg]

I need to thank Falco - I had many of the questions he brought up. I will give my reasoning - probably faulty - for the choices I made in connecting the water heater. First my understanding of marine electrical systems is very limited. I bought 'Marine Electrical and Electronics Bible' which I found difficult to use but got some general concepts.
1. GFI plug. I know you are correct. I had an old plug in my tool box which I used. All of my other AC outlets are connected to a GFI plug. But, faulty thinking, I thought of GFI plugs primarily for appliances you handle, like hair dryers or toasters. As I understand the GFI, it responds to a current surge just like a breaker box but far more rapildy. Will replace the regular plug.
2. Bonding. Here I am really confused. I thought bonding was not to protect us humans but to protect multiple thru-hull inlets/outlets from metal loss. Also I thought this pertained only to DC systems. The purpose of bonding was to make sure that all of the thru-hulls (or other metals) that contacted the salt water interface had identical electrical potential. If there was no bonding, and the thru-hulls had different potentials, then metal ions would flow from one to the other to even the potential and result in destruction of one of the brass or bronze thru-hulls. So I really need an education. The water heater is grounded through shore power and is protected with a breaker. Also there is a magnesium anode in the water heater which I assume is protective of galvanic current.
3. Check Valve: What you say makes sense. However the following was in the water heater manual: "The water utility supply meter may contain a check valve, back flow preventer......... that will create a closed water system, During the heating cycle of the water heater, the water expands causing pressure inside the water heater to increase. The temperature and pressure relief valve may discharge hot water under these conditions which results in a loss of energy and a build up of lime on the relief valve seat...."
It says that if you have a check valve you need either an expansion tank or a pressure relief valve in the cold water supply line. If the system seem to do well without the check valve should I leave well-enough alone.

Again, thanks to all who checked-out my hot water system. I would appreciate more input on the questions raised by Falco.

[rogerbum]

GFI (ground fault interruptors) operate in a significantly different way than a normal ciruit breaker. A circuit breaker opens up when the current draw is greater than the amperage of the breaker. In general, a circuit breaker is designed to protect the circuit itself - in particular the wiring hidden in walls - from drawing too much current and damaging itself.

A GFI on the otherhand, responds to a difference in current between the hot and the neutral of the circuit. In normal operation, an AC circuit should have the same amps going "out" on the hot as "coming back" on the neutral. A difference in current between the two suggests that is flowing to an alternate path (perhaps through you) to ground. If a 5mA difference is detected, the GFI opens on the circuit. A GFI is designed to protect you rather than the circuit itself. Since normal water is pretty conductive (due mostly to disolved salts) it provides a good potential path from something that is hot to anything that comes in contact with the water (like you). Hence GFI are required for all outlets near water to prevent deaths due to things like dropping a blow dryer into the tub. So the suggestion that you use a GFI is a good one. Depending on how you set up your wiring, it is possible to use a GFI in one location to protect other outlets on the same circuit.

edited to correct some typos

[oldgrowth]