Terry and Jo, We're not fulltimers, but we do spend a month in our 5'er each year and usually are out in it for a week at a time every month or so. We have a washer & dryer and my wife is a gourmet cook, so besides showers, we do laundry and lots of dishes. We've never run out of hot water. My dad goes with us, so there's three using the hot water. That being said we do not do all of the above at the sametime, so the hot water heater has time to heat up more water. I don't remember how big the hot water tank is, I think it's 6 gallons. You only have to wait about 10 minutes for the water to be hot when we first turn it on. You won't have to worry the heater will keep up with you.

In both RVs we have owned we had 10 gallon hot water heaters that ran on both electricity and propane.  We don't run out of hot water since the heater reheats fast.  We don't take long showers either.   Our old RV had an Atwood hot water heater and our present RV has a Suburban hot water heater.  With the Atwood the propane heating element was set higher than the electric, while Suburban sets the electric higher. 
With a Suburban you need to replace the anode rod about every year or two, which is also when you use pressurized water (from a hose) to clean the sediment out.  Atwood hot water heaters do not have anode rods but every year or two you should wash out the sediment.

We also have a 10 gallon heater with both electric and propane. Never had a problem with enough hot water, but we sometimes will put it on both if we are taking showers back to back. Supposedly it heats up faster on the dual setting. In 3 years we've changed the anode once. I don't believe it's an issue to be concerned about.

Same here...10 gal tank. Washer/Dryer, showers, dishes, and just using electric. When hooked to shore power the hot water tank is always on. 2 showers will deplete the hot water so we leave 10 minutes between showers so the 2nd person doesn't run out. You could run both electric and propane for faster recovery time.

Mine must be a 10 gallon as well...it's a Suburban, electric/gas.

We just bought a new 2009 Montana last week. With talking to the employee who reviewed the workings of the unit with us, he said it is not true that having the water heater on both electric and propane will heat the water any faster. It would be no different than setting your thermostat at a higher temp to heat the room faster. It heats one degree at a time regardless.

I would have to disagree, a bonfire will heat a gallon of water faster than a  match.The more heat applied the faster it gets hot.

Of course it does, you have 2 sources of heat, the 1800 watt electric heater and the propane burner. The water heats one degree at a time, but much faster. Suburban covers this in the owners manual.

I totally agree with Racerguy. Just my thoughts,but it sure looks to me like two matches would heat the water faster than one match.

A hydro hot water heater sounds good.  Why don't they put them in fifth wheels?

I can tell you from first hand experience that having the electric and propane on at the same time makes a huge difference. We were also told when we first bought our Big Sky Montana that only one on at a time was needed. After a year and a half of full timing and always monitoring the hot water when showering, another RV friend advised us to turn both on. Wow, what a difference. No more fighting over who got the hot water first;) It does state in the Montana manual that both can be on at the same time, however, it doesn't address the advantages. We do not, however, leave them both on all of the time....only when I'm using a lot of hot water for showers or washing dishes or laundry. Judy

Mel, the custom, or semi-custom 5er manuf. will put in a hydro hot or equivalent hot water system if you want to "pay the freight" (the bill). Horizons will, as well as Spacecraft.

I have thought about converting to one from time-to-time, but the expense, along with dealing with the issues that people seem to have with them has convinced me that I'd rather just have a good sized conventional hot water heater. We only turn ours on about 10 minutes or so before we know we will need it and it warms up plenty fast on gas. Or gas and electric if you so choose. The new 14 gallon tanks are plenty of water for any shower I would ever take. Even our 10 gallon is plenty.


-- Edited by Jack Mayer on Saturday 21st of March 2009 10:14:46 AM

I guess the skies the limit on things for a new rv.  I think we will just stick to the basic ol' hot water heater and spend the money on something else.

You might also check on the insta-hot water heaters. I don't know anybody who has one in an RV but I do know a couple S&B who use them. They only "run" when you turn on the hot water, and they heat the water on demand. So you don't have a water tank constantly using energy to heat water. Here's a link to one that came up on a google search: http://www.rvshowermagic.com/

One of the considerations when looking at tankless water heaters is throughput.  On the more expensive brands, like Rinnai, they have high throughput.  This means that someone can be taking a shower, someone else can be running hot water in the kitchen and both will have continuous hot water.  On the cheaper, lower throughput brands, if someone is taking a shower, you won't be able to run hot water in the kitchen.   There just won't be enough throughput to accommodate both uses at the same time.

We have a 12 gal HWH and have never run out of hot water. Our shower is a residential grade shower and we have never had any problems with it. The HWH has to be flushed at least once a year and I change out the element once a year. Other than that we have had no problems in the last three years of living in a RV. Joe and Sherri

I went back to the site I posted and that unit runs on electricity...requires 50A service. The site also says it can easily be taken out of the loop to allow you to use your HWH again. Would be handy for drycamping.

dixie - There are two primary makers of hydronic heating systems. AquaHot (formerly known as HydroHot) is made by Vehicle Systems in Colorado and Oasis is made by International Thermal Research in Canada. These systems, especially Oasis, have their  roots in the marine world - a good place to be rooted as the standards (and quality) there are far higher than our land yachts. Basically, you can think of them somewhat like your oil-fired hot water fan forced baseboard heat in a stix-n-brix.

I also think PrecisionTemp is playing in this elite field with a lower cost propane model I believe and it might also be a direct replacement (in size that is) for a propane water heater.

You typically only find these hydronic systems (AquaHot/Oasis) in the higher and highest end RV's as these systems are very very very well upwards of $12,000 for the unit alone. AquaHot I think was offering a MoHo retro conversion as a winter special.

But once you've had a hydronic system you won't go back. Practically silent, extremely efficient (especially the newer models just off the drawing boards), endless hot water, high heat output, blah, blah, blah. Total full-tilt running electrical loads are a skimpy 10 amps DC (no amps AC) for 50,000++ BTUs when on fuel (either diesel and some newer models are propane) so they boonbdock beautifully. They also have secondary heating by electric resistance coils (like an electric hot water heater) when plugged in.

My AquaHot unit keeps ME and my MoHo (and the basement) toasty warm in the minus 20, yes minus 20 degree Colorado mountains all winter without a hitch - with or without being plugged in! And it doesn't even work up a sweat...

-- Edited by RVDude on Tuesday 24th of March 2009 10:31:07 PM