On-Demand Water Heater? Worth it?

[RobG]

My original water heater is going bad and my extended warranty is going to replace it. The shop doing the work says they can put in an on-demand (RV) unit for the same cost, so I'm considering it. What do you think? Anybody have experience with these? Figured I should ask in case they don't work as well as the residential units. My stock heater is 12 gallons, but it takes an hour and a half to heat up (used to take 40) plus the tank is rusting out too. But it'd be nice to have unlimited hot water (relative to the amount of freshwater I have, plus gray tank space -- assuming not being in a park). I live in the thing fulltime so it'd be really nice.

Thoughts?

Rob

[westend]

In residential use, the tankless heater's best attribute is that it's energy efficient. Since they are flow regulated, it's a poor application in an RV where delivery should be smaller and water use diminished.

[j-d]

I think if you get one that uses LP Gas with Direct Spark Ignition (DSI) AND an Electric Element, you will have the best compromise in RV water heaters.

Our first RV was delivered with a DSI unit but it failed and had it replaced on short notice with an Attwood "standing pilot" heater and it was a pain. Fortunately the replacement also had an electric element and we were able to use electricity most of the time.

Current RV has a Suburban DSI/Electric heater. It heats quickly and recovers well.

Awhile ago, Doug posted the "input" specs on Attwood and Suburban heaters and as I recall Suburban demanded more LPG BTU's (and I believe electric also) so they probably heat and recover a little faster.

It's possible to replace one of the major brands with the other, but I think it's best to stick with whatever brand you need to replace. The mounting scheme and dimensions are different.

[Charlie_D_]

What Doug said. Google "tankless water heater problems"

[RobG]

Thanks everybody. Sounds like I'm gonna stick with my regular heater. When I got the trailer it took 40 minutes to warm up and be ready for use... that's gotten longer and longer over time.

Rob

[pianotuna]

Hi,

None of the portable on demand units will run on electricity. I'd not want one.

There have been a couple of threads on them. The most recent thread is a plea for help on trouble shooting. That says it all, to me.

RobG wrote:
The shop doing the work says they can put in an on-demand (RV) unit for the same cost, so I'm considering it. What do you think?

Thoughts?

Rob

[dougrainer]

1. On demand RV are LP only
2. I am a RV service tech and I would NEVER/EVER have one in an RV. They have way too many problems and Tiffin motorhomes have dropped them as an option because of the complaints. They have continuous too hot, not hot enough or rapid pulsating from hot and cold. They have to have a specific water pressure all the time and INPUT water temp is a big factor in correct operation.
3. They are a continuous source of service headaches. Precision Temp and Girrard both have the same problems, regardless of any product updates they claim to have done or provide. Doug

[SaltiDawg]

RobG,

I'm not an RVer but I learn a lot here about generators.

In the residential world, tankless of on-demand requires NG or LP as a heat source - electric elements can't provide the required heat. Generally, it is my understanding that they also require electricity for control and operation... no to actually heat the water.

I see a couple of RV tankless heaters that say they have batteries to allow for pilot light operation.

Hoping to learn here. Are you/we talking about units that can operate on electric ONLY?

TIA

[DutchmenSport]

The on-demand heater may be a nice option. But one thing you really do have to find out.... does it run on both GAS and ELECTRIC? If you ever find yourself without electricity, you'll be kicking yourself for having this if it cannot be flipped over to gas. Even with full hook-up sites, there may be occasions when you want your gas water heater running instead of electric. For example, if the campground looses power? Which actually happened to us a couple times this year?

[rexlion]

Your fulltime application sounds about perfect for a tankless. But I have heard that the small channels can plug up after a while. Google the subject and you'll find info about house tankless units, which get more use and therefore problems show up faster.

[BuckBarker]

It should be fine unless you deal with hard water anywhere you are. The minerals will plug that darn thing up in no time. A softener is absolutely required for a tankless heater in hard water areas.

[WoodGlue]

My new Atwood 6 gallon regular water heater has an 18 gallon an hour recovery feature. It doesn't take that long to get the water steaming hot either, probably 15 minutes or less. It's almost like an "instant-hot" once the tank is initially hot.

WoodGlue