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on demand hot water

Posted: Thu Jul 21, 2011 2:48 am
by ecastillo
I am fairly new to the world of manufactured homes. I was wondering if anyone has removed their old hot water heater and replaced it with an on demand system. I am thinking about doing this for energy savings and space savings. Is this even possible or allowed in these types of homes?

Re: on demand hot water

Posted: Thu Jul 21, 2011 2:46 pm
by flcruising
Whole house on-demand electric heaters have a much higher load requirement than a standby heater. I doubt your 100 or 200A house panel would be large enough to accommodate it; you would probably have to feed it directly off the meter panel. That being said, the energy savings would probably take a number of years to recoup because of the retrofitting involved. Gas, on the otherhand, may be a better solution as those are commonly mounted externally. Sometimse the main regulator needs changing, but that's pretty much it.

Re: on demand hot water

Posted: Thu Jul 21, 2011 5:33 pm
by ecastillo
Thanks flcruising for your input. It is gas that I would be using. If there is anyone else out there that has done this or can provide helpful information, please chime in.

Re: on demand hot water

Posted: Fri Jul 22, 2011 11:29 am
by flcruising
Sorry, for some reason I automatically assume electric.

Of course it's doable in a manufactured home, as long as it's installed to code (call your building department) and by a licensed contractor.

I suggest you call your gas company and see what they say. Those people encounter practically every condition and would probably be most helpful.

Re: on demand hot water

Posted: Sun Jul 31, 2011 10:55 am
by jpingram5
They payback is a debated topic. Some say they take forever and some say they don't. We been installing only Tankless water heaters so far for about the last 2 years as their becoming more popular. I look at it like this, there more of a luxury than they are energy friendly. It's more about you will never run out a hot water than you will save so much money. Yes they will cost less to run than a regular water heater. But they will also cost 2x as much too or more. And very few gas ones are allowed for mobile homes. I know for a fact that the brand I use, Rinnai, does have a couple of models certified for mobile home use. I've installed them in mobile homes before they were certified with no problems. Now there are several things to remember with these tankless though. A lot of them require a certain water pressure to opertaing. If you have low water pressure then it might not be a good idea. They aren't too terrible to install. Here check them out for more info and maybe find someone who installs them in your area. They could tell you more details.

http://www.rinnai.us/tankless-water-heater/

Re: on demand hot water

Posted: Sun Jul 31, 2011 10:58 am
by jpingram5
FYI

The only reason why this brand Rinnai was not certified for mobile home use before was that they were not "field convertible". Meaning that when you bought one, it was either for Propane or Natural Gas and could not be switched in the future. Now they have a kit to change from Natural to Propane or vice versa. Besides that their safe. Their a Direct Vent Seal Combustion so no worry about drawing air from inside the home.

Re: on demand hot water

Posted: Mon Aug 01, 2011 2:28 am
by ecastillo
Thanks for the additional comments and input. In my situation, I am considering it primarily for the space-saving aspect of the system. Currently, the tank is situated in a room next to my kitchen. If I remove it, it will allow me to open up the wall and add more space in my small kitchen. Also, I hate wasting water, so I won't have to run the water in the shower as I wait for the right temperature, especially during the winter.

Thanks again to all for the input. Keep them coming.

Re: on demand hot water

Posted: Sat Nov 05, 2011 3:23 pm
by Greg S
Further to the water pressure issue. One home in our park has a on demand water heater and when ever the water pressure drops below 30psi he has no hot water. Also he has had to replace some parts and found them to be very expensive. The cost of replacing parts has surpassed his pay back savings.

Re: on demand hot water

Posted: Tue Dec 27, 2011 8:46 am
by Angelina Anderson
Don't know about on demand water heater but I have replaced mine with solar water heater and its working great.More ever I am saving a lot. with reduced energy consumption

Link removed by moderator

Re: on demand hot water

Posted: Tue Jul 03, 2012 8:27 pm
by cnyguy
I have installed a rinnai direct vent unit. A partner helped me run one inch black pipe from the meter through the crawlspace into the closet. Gas volume is critical, too small a supply will cause problems. After removing the small electric tank that came with the house and the wiring to it, I drilled a hole through the wall for the intake/exhaust pipe. The heater itself hangs on the wall and as long as you can 90 degree elbow exhaust right above it, there's no need to worry about condensate, it will drain outside. Slight pitch downwards for this to happen. I haven't put a an outlet in there yet, just using an extension cord for now. My cost was slightly above 1000 dollars to install it and I work in the HVAC trade. I love this unit! Major drawback: teenagers realize they have unlimited hot water, so you have to kick them out of the shower! Most people call these units instantaneous which is incorrect, correct term is on demand. You still have to wait a few seconds for hot water down in the back bathroom.

Re: on demand hot water

Posted: Sat Jan 12, 2013 4:28 pm
by jpingram5
I got a Rinnai RC80i and it works awesome for me. My water pressure floats between 45 - 55 according to a guage I installed inline. I have mine hanging above the washer & dryer and I plugged it in with the washer. Doesn't draw alot of electric and they both run fine when running at same time. The key thing too is quality water. If you have hard water it's best to install and softner system and flush the unit twice a year.