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Hot water question?

PostPosted: Tue Mar 30, 2010 7:27 pm
by jwhite
the last thing I need to buy before my new trailer arrives is a tankless hot water heater and wonder which is best?
I have a 16 gallon water tank that will be for the shower and sink I will not be takeing real hot showers or for very long something more like a rinse off bird-bath.
are there any 110 volt heaters that draw a low amp? my generator is a 13amp and am not sure if that will work?
I am looking into the propane type but I think that it has to be vented or made for indoor use?
any advice here on this subject?
thanks

PostPosted: Tue Mar 30, 2010 9:41 pm
by 8ball_99
Your going to want a propane Hotwater heater.. Even more so if you want a tankless. Electric hot water heaters pull a ton of power and the small under the counter ones aren't very good. I installed a 6 gallon propane water heater like what comes in pretty much every RV. The tankless ones on Ebay dont look bad and the price is pretty cheap. You will need some kind of vent for them. Also the cheaper models are made for outside use so I'm not 100% how easy they are to vent through a roof or wall. They are also setup for the LP gas bottle to be pretty close to them. Your going to want to mount your bottle outside and run a line.

PostPosted: Tue Mar 30, 2010 9:48 pm
by pete42
Somewhere on this site I saw a propane heater that was mounted on the front of the trailer with quick connects for the propane and hot water and water hose.
They only used it when they had water hook-up but I'm sure it could be plumbed into the on board water tank.
being mounted outside it didn't need a vent through the roof or side of the trailer. Just a thought
I found someone who has a outside tank check out JEEP9806's album

PostPosted: Wed Mar 31, 2010 6:28 pm
by Shadow Catcher
We have a 6gal gas electric water heater, Electric when on shore power gas when not. Bosch makes some very nice thankless heaters and when our home water heater fails that is what I will replace it with.
"The Bosch AquaStar Model 1600H incorporates a revolutionary hydro-generated ignition system, allowing the water heater to operate without a standing pilot, electricity, or a battery."

PostPosted: Wed Mar 31, 2010 6:40 pm
by jwhite
Thanks for the replies with alot of searching on Ebay I found a 1.6 gpm NG Ventfree tankless gas water heater made by Excel = it is just over 200.00

MY trailer is ready I pick it up from the factory tomarrow,and the work begins.

PostPosted: Wed Mar 31, 2010 10:57 pm
by madrider
jwhite wrote:Thanks for the replies with alot of searching on Ebay I found a 1.6 gpm NG Ventfree tankless gas water heater made by Excel = it is just over 200.00

MY trailer is ready I pick it up from the factory tomarrow,and the work begins.


NG?
Im I missing something here? Can you get bottled NG? Around here all we can get is propane for our campers.

PostPosted: Wed Mar 31, 2010 11:29 pm
by 8ball_99
Pretty sure NG doesn't come in a bottle :roll: My neighbor is really kicking around getting a tankless just so he doesn't have to cut a large hole in the side like mine and because they go for about 185 on Ebay. I'm pretty sure ANY gas hotwater heater is going to need some kind of venting. Even if they are clean burning they will put out a Ton of heat that will need to go somewhere.
I'm pretty happy with my 6 gallon suburban heater.. Its electronic so no pilot light. Heats 6 gallons in about 10 mins just flip a switch to turn it on. Its the same unit that comes in almost any New RV. Not saying they are better just saying they are tried a true. Mine also has the electric heating element so it can run on either gas or propane or both from my understanding.

PostPosted: Thu Apr 01, 2010 7:05 am
by Shadow Catcher
Most (but not all) natural gas appliances can be converted to propane. The vent less however does not mean a confined space, this is so not a good idea, you could wake up dead. :(

My experience

PostPosted: Thu Apr 01, 2010 8:46 pm
by Nathan N
I installed a PowerStar AE 12 Tankless Point-of-Use water heater in the shop. I don't use a lot of hot water out there so figured it would be a good fit.

http://www.homedepot.com/Building-Materials-Plumbing-Water-Heaters-Point-Of-Use/h_d1/N-5yc1vZ1xh7Zaqcu/R-100019685/h_d2/ProductDisplay?langId=-1&storeId=10051&catalogId=10053

PowerStar AE-12 electric, tankless point of use water heater supplies endless hot water, installs easily under any sink in a horizontal direction only. Saves energy and water because there is no heat loss from long pipe runs. Perfect solution for home & office sinks with a 5 year limited warranty. The AE-12 is NOT intended as a whole house water heater. 50 amps, 240 V, and 12 Kw.

Requires 240V Hard Wiring and 50 Amps
Eliminates Long Waits For Hot Water
Easy Installation; Installs Vertically or Horizontally
Point-of-use For Hot Water To One Sink
Thermostatic Adjustable Control
MFG Brand Name : PowerStar
MFG Model # : AE-12
MFG Part # : AE-12

Flow Rate @ 45°F Rise : 2.0 gal (US)/min

Yep, that is 240VAC and 50 Amps. It is not installed directly under the sink but is within 10 feet. Opening the faucet up wide open will allow too much flow for the heater to keep up. Opening about half way I can hardly hold my hand under it.

I don't believe I could recommend it especially for a camper. A propane one might be feasible I just don't know anything about them.

PostPosted: Thu Apr 01, 2010 9:10 pm
by Trackstriper
jwhite,

Couple of thoughts. You may or may not want to operate with propane. That adds complexity unless you will also be using it for heat. I'm working on a cargo conversion and wish to have a real shower while on the road, so I settled on a six-gallon standard electric water heater, as available from Lowes, etc. It's not the lightest unit around at about 45# empty but it has the advantage of using standard screw-in heating elements.

All of the smaller, under counter, point of use water heaters that I came across had elements in the 1500-1600 watt range, but most of them had dedicated, special elements designed to go into a tight package. As my heater had a standard screw-in element I exchanged the 1600w element with a 1000w element, available online here and there. That way I wouldn't be working my 1600w generator at the max. It also will allow me to be totally electric which is helpful if I can find shore power. Sure the water will take a little longer to heat, but not much.

GE makes a small 2.5 gallon heater that Home Depot carries, it might also use standard elements that could be changed out.

PostPosted: Thu Apr 01, 2010 9:57 pm
by jwhite
Thanks again for the replys,I bought a small electric water heater off ebay and when I hooked it to a water hose I could not get it to heat water so I contacted who I bought it from and they said I need a
(water flow tap )to make it work?
is this a valve that slows the water flow?

PostPosted: Fri Apr 02, 2010 5:12 am
by Nathan N
jwhite wrote:Thanks again for the replys,I bought a small electric water heater off ebay and when I hooked it to a water hose I could not get it to heat water so I contacted who I bought it from and they said I need a
(water flow tap )to make it work?
is this a valve that slows the water flow?


That is what I would guess. What make/model is the water heater?

After my learning experience with the Bosch point of use unit (240VAC @ 50 Amps) only providing 45 degree F raise at 2.0 gallons per minute flow, I would like to see the specs on your water heater.

PostPosted: Fri Apr 02, 2010 5:47 am
by len19070
My hot water needs are few. And never under pressure.

I use the Campgrounds Shower's or a Solar shower (only at certain places)

So most of my hot Water needs are for dishes and washing up.

If I don't have electric I put a pot on the stove.

If I do have electricity....

Image

Happy Trails

Len

Water Heating Around The World

PostPosted: Sun Apr 04, 2010 5:01 pm
by Engineer Guy
Most all the world I've visited uses 'demand' or 'flash' heaters. Space is too expensive to heat ~40 gallons of water and let it sit there. Case in point, my Bro-in-Law's ~2,000 sq. ft. Apt. in Hong Kong with a 'flash' HW heater is $15,000/month. Yep, $15,000. His employer, a major Air Freight Company, picks up the tab.

Nat Gas or Propane flash heaters work very well. As with electric 'flash' heaters, which I have, you have to establish a certain minimum water flow to get the heater to kick on. Then, especially with newer HW heaters, you can throttle back the flow and still get hot water. Electric 'flash' heaters draw the proverbial guano-load of amps.

For my future CT conversion, I plan to use solar HW circulated through black tubing on the CT roof via a HW solar panel and a solar powered +12 VDC pump. Sun comes out; HW gets heated via black sprinkler tubing coiled up on the CT roof under a tempered glass box collector. Water storage will be in a small [~12 gal.] Big Box Store electric HW heater that has extra insulation around it, and can also run off of shore 120 VAC power.

Another trick to is heat HW to insane temps, BUT install a 'tempering valve' on the HW heater output. A major RV Manf. does this and claims their HW heater outputs ~50% more hot water. If one were to store ~180 degree HW in a super insulated tank, and add some cold water by using a tempering or mixing valve on the output, you could store a bunch of HW and make it last longer.

PostPosted: Sun Apr 04, 2010 6:06 pm
by 8ball_99
In a home on demand makes alot of since because you probably need hot water at night for a few hours or an hour in the morning. You also have plenty of power. So keeping all that water hot 24/7 doesn't make alot of since. RV it doesn't make as much since.. You only need very little water maybe once a day.. Even with a tank heater like mine you just turn it on 5-10 before you need water and your good. Its not like a 50 gallon water heater in your home where it takes 45 mins to get up to temp.