water heater question

[Capt Kangeroo]

My 8yr old grossly over priced 20 gallon Raritan hot water heater is leaking. To replace it is a ridiculous $800 for what appears to be a low end unit of questionable quality. Mine is a measely 1200 watt and doesn't even have a drain or engine connections. I'm thinking of replacing it with a non-marine Whirlpool unit from Lowes for $299. It is 1500 watt and has a drain as well as`side and top connections.

Has anyone tried a non-marine unit or know of any reason not to? I figure even if I have to replace it every 6 to 8 years I'm still ahead of the game.

 

[sum escape]

Water Heater

Here is what I just put in my boat to replace the 10 year old leaky one. 20 gal, 240V, no heat exchanger. Less than $550 but plus freight.
Defender.com Search Results: 501253

 

[O C Diver]

If you're nor going to use a heat exchanger, no reason to go with a marine unit. Just make sure you properly secure the new unit.

BTW, it's a water heater. You don't heat hot water.

Ted

 

[Capt Kangeroo]

Thanks Guys.

That's pretty funny Ted, I stand corrected, never thought about it before I have always referred to them as hot water heater

 

[psneeld]

belive it or not....a 750 watt unit can do a great job.


I bought the less expensive Isotemp basic 8 gallon with the 750 watt element.


It heats faster and retains heat much longer than my Kuma/Seaward square aluminum 6 gallon heater of old.


Two of us take back to back showers with no problem.


Nice specs and materials.


My only complaint was the elements are special...not standard big box type.

 

[seadogmike]

Just to ad a thought here, If you use a hot water heater that is designed for home use, please get a marine electrician to hook it up for you. There is one subtle difference between them.There is a ground strap in them that needs to be removed.Failure to do this will bypass the Galvanic Isolator, and if it ever shorts will make the water electrically hot around the boat. Just my 2 cents.

 

[psneeld]

Just to ad a thought here, If you use a hot water heater that is designed for home use, please get a marine electrician to hook it up for you. There is one subtle difference between them.There is a ground strap in them that needs to be removed.Failure to do this will bypass the Galvanic Isolator, and if it ever shorts will make the water electrically hot around the boat. Just my 2 cents.

Can you please amplify where the strap is usually located and what part of the heater it touches that you wouldn't want stray current to be connected back through the green ground?

It may help others with DIY installs.

 

[folivier]

And the Raritan uses a typical element. I replaced a burnt out one on the 20 gal. Raritan in my older motorhome with a 1750 watt unit and it worked fine. Even emailed Raritan support and the tech said it would work fine as long as the wiring was large enough to handle the extra amps.

 

[rwidman]

Why would you want to heat hot water?

I am really fond of my marine water heater with heat exchanger. If you stay at the dock or in marinas exclusively, this may not be important to you but I can cruise all day, anchor, take showers and still have hot water the next morning. No electricity needed.

As for using a non marine water heater, do you have a gasoline powered boat or diesel? The thermostat in a non marine water heater is probably not ignition protected. That would be a safety issue.

I think when it comes time to sell the boat, a non-marine water heater would be an issue for an informed buyer or a competent surveyor.

In the end, it's your boat and you can do anything you want with it. If it were me, I would install a marine water heater with a heat exchanger. It would be an improvement over the original.

 

[seadogmike]

Can you please amplify where the strap is usually located and what part of the heater it touches that you wouldn't want stray current to be connected back through the green ground?

It may help others with DIY installs.

There typically will be a strap from the neutral to the ground. This is also true with Washers, dryers, sometimes dishwashers, and ovens. By law there is a notice label on the unit that tells you where the ground is located that has to be removed.
The picture attached shows an electric range with the strap in place.

 

[psneeld]

As long as it is installed well, a non marine water heater doesn't raise too many flags....not in my circles or on past boats.

But as I posted, I am curious if there is an electrical hazard I was unaware of.

 

[Bay Pelican]

belive it or not....a 750 watt unit can do a great job.


I bought the less expensive Isotemp basic 8 gallon with the 750 watt element.


It heats faster and retains heat much longer than my Kuma/Seaward square aluminum 6 gallon heater of old.


Two of us take back to back showers with no problem.


Nice specs and materials.


My only complaint was the elements are special...not standard big box type.

Bought the six gallon unit, love it and has the provision for the engine coolant 750 watts and a plastic case.

 

[psneeld]

There typically will be a strap from the neutral to the ground. This is also true with Washers, dryers, sometimes dishwashers, and ovens. By law there is a notice label on the unit that tells you where the ground is located that has to be removed.
The picture attached shows an electric range with the strap in place.

Cool...not sure I have seen that...will be on my checklist from nowbon!

 

[rwidman]

I see it but I don't believe it. My recollection of the National electrical Code only allows connecting the neutral and ground together at the entrance panel.


It's been years so maybe it's changed or my memory has failed me.

 

[seadogmike]

If the heater element, or any other current device such as a light or motor shorts, it can induce voltage into the grounding/bonding system. This voltage/current will flow back to it's source (your pedestal) by any and all paths, including the water your vessel is sitting in.

 

[seadogmike]

I see it but I don't believe it. My recollection of the National electrical Code only allows connecting the neutral and ground together at the entrance panel.


It's been years so maybe it's changed or my memory has failed me.

The ground and neutral should only be connected at the source (I.E. the pedestal.

 

[seadogmike]

http://www.trawlerforum.com/forums/members/12262-albums455.html
Maybe this will help.

 

[Old deckhand]

A residential water heater that has upper and lower heating elements does heat hot water. When the water is run the upper element comes on and heats the hot water as it leaves the heater and makes the hot water a little hotter.

 

[rwidman]

The ground and neutral should only be connected at the source (I.E. the pedestal.

Not at the pedestal, at the marina's service entrance/ breaker panel. That's the "source".

 

[seadogmike]

My Mistake in wording. Either way they should not be connected at the appliance.

 

[Peter B]

Why would you want to heat hot water?

I am really fond of my marine water heater with heat exchanger. If you stay at the dock or in marinas exclusively, this may not be important to you but I can cruise all day, anchor, take showers and still have hot water the next morning. No electricity needed..... If it were me, I would install a marine water heater with a heat exchanger. It would be an improvement over the original.

I would tend to go with the above also. I replaced a very old rusty heat exchanger type water cylinder in our boat with an Isotemp Standard 42L unit several years ago, which as heat exchanger and element. We don't have 240v AC out on the water, so we just use the element to preheat the water by connecting it to shore power while loading up, and in 20 mins it is about bath temp hot. The engine then takes over from there and we are never out of hot water the rest of the trip. In fact the heat exchanger makes it too hot, and we have to remember we don't have the 50º C temp limiter valve on her like we do at home, and to mix in plenty of cold.

Believe it or not the old cylinder still worked, (the rust mainly in the outer lining, the tank being copper), but slowly because, (as I found out once removed), because of muck in the heat exchanger piping.

 

[Capt Kangeroo]

Thanks S-Mike for the info regarding the neutral/ground. I bought the Lowes "water heater" but it appears to be wired normally without any connection between neutral and ground. Neither is there a sticker referencing such connection. Perhaps it is an issue that varies from State to State.

 

[rwidman]

Thanks S-Mike for the info regarding the neutral/ground. I bought the Lowes "water heater" but it appears to be wired normally without any connection between neutral and ground. Neither is there a sticker referencing such connection. Perhaps it is an issue that varies from State to State.

Most states follow the National Electrical Code. They might add a few things but I doubt they would change the part about grounding only at the entrance panel.

 

[CaptTom]

Thanks S-Mike for the info regarding the neutral/ground. I bought the Lowes "water heater" but it appears to be wired normally without any connection between neutral and ground. Neither is there a sticker referencing such connection. Perhaps it is an issue that varies from State to State.

From the picture of the grounding strap posted earlier, it appears to me that it's a 240VAC appliance, with two hot (red and black) and one ground (white) wire. No green safety ground.

It's starting to make sense. Recently an appliance salesmen was trying to sell a 4-conductor plug for my new range. I'm guessing there's a push underway to add a safety ground to all 240VAC appliances, like we have in the 120VAC world. It's not a bad idea. I had an old range once that would give you a shock if you touched it while touching anything else that was grounded. Needless to say I replaced it.

Of course, you'd need to remove the bonding strap to convert your 3-wire appliance to a 4-wire plug. I might just do that when I install my range. Only I'll buy the cord on line for half what they wanted to charge me.

And, if Capt Kangeroo bought a 120VAC water heater, that might explain why it's wired "normally" and without a sticker. Most boats in the 30-35' range have smaller water heaters (6-12 G) that work on 120VAC, as do some "apartment size" heaters. Full-size home units and larger boats will use a 240VAC supply.

 

[psneeld]

From the picture of the grounding strap posted earlier, it appears to me that it's a 240VAC appliance, with two hot (red and black) and one ground (white) wire. No green safety ground.

It's starting to make sense. Recently an appliance salesmen was trying to sell a 4-conductor plug for my new range. I'm guessing there's a push underway to add a safety ground to all 240VAC appliances, like we have in the 120VAC world. It's not a bad idea. I had an old range once that would give you a shock if you touched it while touching anything else that was grounded. Needless to say I replaced it.

Of course, you'd need to remove the bonding strap to convert your 3-wire appliance to a 4-wire plug. I might just do that when I install my range. Only I'll buy the cord on line for half what they wanted to charge me.

And, if Capt Kangeroo bought a 120VAC water heater, that might explain why it's wired "normally" and without a sticker. Most boats in the 30-35' range have smaller water heaters (6-12 G) that work on 120VAC, as do some "apartment size" heaters. Full-size home units and larger boats will use a 240VAC supply.

Pretty much what I was thinking....having wired a couple small home units on a boat...I had never seen them wired differently than a marine unit as they were 120V....and never say that sticker.

 

[bayview]

I see it but I don't believe it. My recollection of the National electrical Code only allows connecting the neutral and ground together at the entrance panel.


It's been years so maybe it's changed or my memory has failed me.

+1

 

[bayview]

We rarely used the electrical heater as the engine coolant heater would supply several days of hot water for showers. Only problem as that care was needed because the water was too hot.

 

[Alaskan Sea-Duction]

Good discussion. Bleeding (Stray) voltage/amps into the water kills folks every year, especially at marinas. If you are on the hook and have the genny running and your HWH is on and it is putty stray voltage into the water, anyone jumping into the water is basically dead. Please be careful.


When I built my dock, I made sure I had a "floating" neutral. No ground until the source which is on land.

 

[sunchaser]

Full-size home units and larger boats will use a 240VAC supply.

My 17 gallon Torrid uses 110V. I prefer glass lined tank with engine heat exchanger so stuck with boat variety tank on last replacement.

 

[FF]

"Full-size home units and larger boats will use a 240VAC supply."

True BUT the heating element is only $20.00 or so and the operating thermostats dont care.

RHEEM sells plastic lined super efficient (commercial and home) units that do not wear out inside.

The alt energy folks sell double wall heat exchangers that can later be installed/

The double wall is because anti freeze is a poison.

http://www.rheem.com/product/residential-electric-water-heaters-marathon