Tankless Hot Water

[pbahlin]

Forgot to mention the concern over pressure and flow. The issue is that the units turn on when they detect FLOW of about 0.5 GPM. If you like to trickle your hot water they probably aren't for you. I found that this was never an issue but that's just me. I think if you do a test you'll find that .5 GPM is pretty low for most folks.

As far as I know they aren't sensitive to pressure in anyway. However, if you're pumping with one, say with a domestic heating circulator pump you have to make sure it can make sufficient 'head' pressure since they have small tubing inside. Normal water pressure of 40 pounds or so is not going to have any issues with these things.

In an RV where you are using it for hot water only, you'll have 40 pounds of differntial pressure across it no matter how many faucets are open. If it's sized correctly you'll be able to scald yourself at each for a very long time.

BTW I bought mine about 6 years ago for $600 on the internet. It's about the size of a small suitcase.

[chieflawdawg]

I have the Rennai Tankless heater on my stick built and love it. We have 3 1/2 baths. This is a continuous hot water system that once it gets to the temperature, it stays there until you turn it off. It does take about 30-45 seconds to get hot water one end of the house though. But once it gets there, it stays there as long as you want it. Would love to hear how it works in the 5er.

[Exnavydiver]

We have a Bosch 2500 tankless in our stick house. we are on well water and the temp coming out of the ground is 46 degrees. When we retro fitted the new system I removed the heating elements from our old electric 55 gallon tank style water heater and used it as a tempering tank. The average temp in our basement is around 65 degrees so we are getting about a 20 degree shift in the supply water from ground and tankless unit. Even before I started using the old water heater as a tempering tank the Bosch unit kept the shower and dishwasher in plenty of hot water. I have taken showers while Betsy was doing laundry and had no drop in temp. I have no complaints about our tankless. The flow is rated at 6.5 gallons per minute and our well is doing well at 4.5. Other than the delay in getting hot water from the heater I have no problems with it and would install one in the rig in a heart beat if you could get one RV certified... Dave

[exav8tr]

Are these systems gas operated or can you get them in all electric? If so, are they as cost efficient as an electric HWH?? Inquiring minds want to know. How about it Dave, what is yours? BTW, While living in Spain in the 70's, they were called "Flash Water Heaters" as they were usually located near the kitchen sink and would flash when the hot water was turned on. Kind of scary at first.....We used butano gas to power them.......So they have been around quite a long time....

[Exnavydiver]

Our unit is propane and the savings is substantial. Out electric bill was cut in half just by removing the elect water heater from the equation. It is not that hungry when it is in use either. I cannot give you a usage amount because I am working off a 500 gallon tank
but this last summer we went from 41% to 39% from may to Sept 5th. The only things using the propane were the drier and the water heater. We did a fair amount of laundry and being as hot as it was in northern Wisconsin last summer we both took at least one shower apiece a day, some times two or three...

[scductman]

I can tell you this thread getting very interesting. we got our elect bill for last month friday and I am still having trouble getting my breath. HWH with one element 37.5amps dryer, stove, heat pump it never ends. OOOOOHHh yes it does SELL Stick house move in montana. YEAH.
bobby

[MAMalody]

I just forgot the name of the mfg, however, it is a propane only system. Water output is at 125 degrees. I don't really have a concern about water flow, however, in the worst case scenario, I can always fill the fresh water tank and use the water pump for a feed. I don't think I will have to. I have never been anywhere the water flow is less than 1 1/2 gal/min so I don't think there will be a problem. My wife loves long hot baths, so I am willing to pay more if necessary, but I don't think the cost will be any more. The install looks pretty simply, water in, water out, gas in. All those lines are already there. There is one more interesting feature in this unit. It also will have a unit on it that if the water falls below 40 degrees it will come on to warm the water in the system so it doesn't freeze. The water flowing through for this purpose will flow into the fresh water tank or it can drain onto the ground. I am having mine hooked into the fresh water tank.

[D and M On The Road]

MAMalody... please say hello to Kaye for me.

If people are concerned about the efficiency of hot water heaters, (tank or tankless) they can always check out the ones by A. O. Smith Company, http://www.hotwater.com/
They are endorsed by Ed Begley, Jr. on his “Living with ED” Series on HGTV.
Website for the show is: www.livingwithed.net

In fact, his show is very entertaining even if you aren't interested in learning how to "live green". I like to watch Ed spar with Bill Nye (the Science Guy) and Jay Leno as they try to outdo each other with "living green".

You can also read about the previous 3 season's episodes by going to:
http://www.livingwithed.net/eguide.asp and click on the tab, “The Episodes” to see a synopsis of each episode. There is lots of great information on solar and wind power.

Did you know there are wind turbines for RVs?

[Art-n-Marge]

This is sounding better and better all the time! For what some of you have done paid for your RV system, it's comparable to the price of a traditional tank system for an RV. I wish this was the case for the stickhouse where these systems are so overpriced.

[garyka]

I put one in my stick house about 8 years ago and would not be without one.I no longer keep 40 gals of hot water 24/7.

[nowinter]

Exav8tr: You asked about electric powered instantaneous water heaters. For a stick house, they can be powered by electric, propane and natural gas. For electric, they require significant instantaneous electric demand and I would recommend a minimum 200 amp primary service. I am not sure if electric is offered for an RV. You can also purchase small units that can be installed precisely at the point of use, and these typically are electric. They are handy if your point of use is a long distance from the primary water heater, such as a small sink. Like I previously stated in a post, I have had a natural gas, tankless system for a couple of years in my house and am very happy with it. If you are replacing an electric hot water heater, the energy savings would be significant. But we replaced a powered exhaust, natural gas water heater and the energy savings was not that great. We did it more for convenience and space savings.

[exav8tr]

nowinter, Thank you for the valuable information. Always nice to get first hand knowledge as you and others have posted.....

[Wild Horse]

Ya know, this thread exemplifies the value of the MOC forums. The level of knowledge, experience and all around know-how here is only exceeded by the downright comaraderie of it's members.
Been here a year, luvin' every minute of it and learning more each day.
Thanks to EVERYONE.
Bill

[SlickWillie]

We were looking at SOB today in San Antonio....it only comes with tankless water heater. I actually sat down and talked with a factory rep in town for the RV show this weekend. He pointed out that you're not hauling around that extra 6-12 gallons of water, and that his company had ran tests and found the tankless water heater (propane) to be highly efficient. Sure has me interested.

[nowinter]

I did a little research on tankless water heaters for RV's. I could be wrong, but I do not think you can operate a RV tankless water heater from both propane and/or electric power. I think it must be only one or the other. The electric models appear to require a minimum of 30 amp or 50 amp with 110 volt service. Some also come with 220 volt service, but would be a bit more complicated to wire. Unlike the tank type heaters that have the availability to operate in either propane or electric (like most of us have now). Please let me know if there are heaters that can operate in both electric and/or propane.

[D and M On The Road]

Rats! I forgot to more closely check-out the tankless hot water heater that CampingWorld had on their shelf when I was there on Tuesday. Does anyone know about that model?

[SlickWillie]

quote:Originally posted by nowinter

I did a little research on tankless water heaters for RV's. I could be wrong, but I do not think you can operate a RV tankless water heater from both propane and/or electric power. I think it must be only one or the other. The electric models appear to require a minimum of 30 amp or 50 amp with 110 volt service. Some also come with 220 volt service, but would be a bit more complicated to wire. Unlike the tank type heaters that have the availability to operate in either propane or electric (like most of us have now). Please let me know if there are heaters that can operate in both electric and/or propane.

I've never run across a dual fuel model. Electric in the RV is just not feasible to me.

[scductman]

Alot of the older 5ers only came with propane IIRC. I don't think it would be a deal breaker for me with gas only. this is begining to be a very interesting thread. I need to find out about Price and how to install. Hey another mod!!!.
bobby

[CORattler]

Just saw this at Tweetys
http://tweetys.com/girard-tankless-r...-suburban.aspx

[MAMalody]

quote:Originally posted by CORattler

Just saw this at Tweetys
http://tweetys.com/girard-tankless-r...-suburban.aspx

Hey! That's my unit. A little more than I am paying but the same unit. I should find out in the next couple of days about the installation. The door is due in tomorrow.

D & M - Kaye says Hi! She was just thinking about you the other day.