Other tankless waterheater options - not RV500

[Knoxvegas]

Has anyone used/installed other types of tankless water heaters aside from the RV-500? From what I have found those go for ~$1000, which seems high and they require external venting.

I see several of these "point-of-use" type water heaters like the Eemax and Steible for <$200. I guess that the disadvantage to these is that they are electric only, but they do not need to vent externally?

Anybody have experinece with these type units or any comments?
I have a 64 safari 22'.

[InsideOut]

We used the ShowerMate M-500...it can vent through the floor instead of a wall panel. It's propane, made for boats and it works great...but it too is over $1000 ~

One of the problems with the +/-$200 residential insta-hot water heaters is they are not intended for moving down the road. I would think that is only asking for trouble...

Shari

[Jammer]

There are better and worse electric units but they require an enormous amount of electricity while in operation especially in areas where the incoming water is fairly cold. A 50A 240V service would be barely sufficient.

[Knoxvegas]

So you all are saying quit being so cheap and pony up the funds eh..

[richinny]

one of the issues noted by our member Lewster, is that you should have a unit rated/approved for RV use.

[NJtoNC]

i bought and installed an RV on-demand water heater - it is propane and needs to be vented, but it was less than $200. the only downfall is that you wont get the water over 90 degrees if its less than 40 degrees in your trailer - ie, it only heats the water about 80 degrees. but i dont plan on winter camping, so its not really a problem for me. its a Marey brand.

Marey Heater Corp

[lewster]

As a public safety message, let me re-iterate that the Precision-Temp RV 500 is currently the ONLY RV tankless water heater that is approved for RV use by the RVIA, which is the industry organization that writes the specifications for all RV manufacturers.

There are a couple of units that combine hot water production AND hydronic heating, like the Precision Temp Twin-Temp and Twin-Temp Jr, and the new Aqua-Hot 350 LP unit. Again, these are the ONLY UNITS THAT ARE RVIA CERTIFIED FOR RV USE!

There is also a good selection of diesel fired tankless systems that incorporate hydronic heating from OEMs like Aqua-Hot, Oasis Thermal Systems, Webasto Thermal Systems, and a few others.

Again, go cheap and your safety is at risk! ANY DOMESTIC UNIT IS NOT RV RATED and will develop problems because it is not designed for the rigors of road vibration.

THIS PUBLIC SERVICE ANNOUNCEMENT IS NOW OVER.

[BrianD.]

I'm wondering if people who use these tankless systems end up with a lot more fresh water, AND then grey water being used up.

This would seem to be a problem if you were off shore with the fresh water supply, as well as rv parks AND off shore with having to dump the grey water sooner as well.

[VanSyncro]

I have a brand new in the box RV500 with the cold weather package and the silver door for sale. If interested please pmail me.

Van

[2xS]

Kudos to Jammer... nailed it.

I have been using the 120V 4kW Hoter Excel alongside my propane water heater for about 6 months now:
Shimron Energy Ltd. COMPANY, Tech Support
It retailed for about $80 on their eBay store, and it had the best performance specs I found of any 120V model: 40 degree temp rise @ 0.5/gal a minute (which is nothing). However, I live in San Diego, and this unit is wonderful for even the best case scenario with one of these things: a hot shower. But it has been through many northern states lately, and the performance there wasn't sufficient to shower.

At MAX, through a standard 50A service, you could run a 240V, 12kW unit; anything greater than that will blow your breaker: 12kW / 240V = 50A. Eemax makes a model that falls within the specs for under $300 (if you look carefully); it boasts heating 1.5 GPM by 52°F:
Eemax - EX012240T

Couple more things:
1) If your trailer is wired for 50A already, then electric tankless is not for you; you will need that 50A connection exclusively for any respectable instant hot water heater.

2) Be prepared to spend about $100 more on the cable you will need to run exclusively to the device.

3) Be sure to have a water regulator connected; this will restrict the amount of water that flows through the unit, and thus, make it warmer.

A lot more good info here:
Energy Savers: Sizing a Demand (Tankless or Instantaneous) Water Heater

[Riverrat6270]

Sorry, but you would have to beat me with a stick to use Eemax heaters. Been spec'd on commercial applications for a couple of years. After last installation, 1 of 4 units leaked on installation. Previous application 6 heaters installed and to my recollection all failed within the first year. One almost burned the bank down.
Seems like a good idea but haven't found a brand that didn't have either failure or lack of power to supply enough hot water.
Being a plumber that has to make an architects idea work I think qualifies me to make these statements.

[2xS]

I was just trying to give an idea of MAX spec models; I've never personally used that unit... It's good to know the a knowledgeable community member doesn't approve of the Eemax product. I just want to emphasize that the unit needs to be <12kW no matter what manufacturer it is.

I love my Hoter, but by no means would I rely on it solely for hot water if I didn't happen to live where the incoming water temp is warm all year. Here it works well enough to shower and do dishes (but not at the same time). I imagine their 240V, 7kW model would work real well for colder climates with conservative water consumption...

[stevedahl]

Hello Van;

You can email me directly kstevedahl@juno.com
How much are you asking for your Precision Temp RV 500

Thanks

Steve

Originally Posted by VanSyncro

I have a brand new in the box RV500 with the cold weather package and the silver door for sale. If interested please pmail me.

Van

[hshovic]

As far as tankless goes, I was interested last year, and looked into it with Lewster and the installation user manuals (RV500).
Though it looks good in general, it is not practical in cold weather. Freezeup is a major potential, with major damage. It has a heater and a frost pack, but the cautions and precautions against freezing
convinced me it is a bigger hassle than it is worth, if you go or stay where it freezes.
If you go only where temps are higher than 40 F than it sounds good.

[dizzyizzy111]

Hi my name is Rob over in Seattle WA. Do you still have the RV500? If so how much? You can e-mail me or call my cell. Thank you very much.. andrewsre2001@yahoo.com Ph# (253)205-9817.

[rmkrum]

Originally Posted by hshovic

As far as tankless goes, I was interested last year, and looked into it with Lewster and the installation user manuals (RV500).
Though it looks good in general, it is not practical in cold weather. Freezeup is a major potential, with major damage. It has a heater and a frost pack, but the cautions and precautions against freezing
convinced me it is a bigger hassle than it is worth, if you go or stay where it freezes.
If you go only where temps are higher than 40 F than it sounds good.

Politely disagree...we use ours regularly in temperatures below freezing, and as long as it has power and propane its fine. it will light off and heat up automagically to protect all the innards including the electronics from freezing. Just have to leave it turned on...

Setting its temperature control knob to "winter" gets plenty of hot water in temperatures that result in the city water hose freezing up right after dark. (Yeah, I disconnected even earlier the next night--just dumb lucky the hose and external filter did not burst. )

My wife would probably not appreciate it if we did not have a tankless to support her long hot shower habit

[hshovic]

But, if the water heater is off, and you are travelling down the road in sub-zero temps, freezing is a potential. And if you run out of propane, or if you turn it off to replenish propane canisters, or lose power it may freeze, or if you (as many do), keep all propane appliances off when traveling, or if the electronics has a fault, or if you leave it outside for a night when you arrive home, turn everything off and the temp goes low, it may freeze. These are all low prob events, but there are a lot of them, and I (or my wife) have made all the mistakes above at least once, (but without serious consequences). As long as it is on, no problem.

[rmkrum]

IMHO, with reasonable care the benefits greatly outweigh the risks of anything going wrong. I've never had to shut off all propane to change out a tank--that's why the AS has an auto-switch regulator, and I carry two spare tanks in cold weather. I had more issues with the cheap 6 gallon standard hot water heater due to noise, drain and winterizing issues, and low capacity for the way we camp. The biggest issue was running out of hot water during the third shower in a row--usually mine...


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