Instant Hot Water-(again)

[PP]

We currently have a single 6 gal gas/elect water heater installed in a custom compartment next to the generator. It doesn't get enough ventilation to operate on gas and melted the circuit board. Since then we've been using it strictly on electric and I disconnected the gas line from it. Fortunately, it didn't catch the bus on fire!
We're thinking of installing a couple of 120V 29Amp instant water heaters made by Triton. ($210.bucks each) One in the bath plumbing, and one for the kitchen.
My question is-does anyone have any first hand experience with these or any 120V instant hot water heaters? They claim to be rated at 2GPM just like the lower amperage 220V units. I would go with the 220V units and run them off the dryer circuit, but experience has proven that 50amp poles are not always available and I'm not going to fire up the jenny every time we need hotwater LOL.
Let me know what you think and don't hold back. Thanks, Will

[Sean]

For that kind of money ($210x2) I would get an 11-gallon Seaward, available for less than $300.  Works great on 120v -- we have scalding hot water in 30-40 minutes on 120, but more importantly, if you plumb it into your heater loop, you'll get hot water for free every time you drive.  If you are concerned about 170-degree water, add a tempering valve, another $40 or so.

Our shower runs 3-4gpm, so I'm not sure how well an instant unit rated at 2gpm would keep up.  Also, 29 amps is a lot of juice; if you're already concerned about availability of 50-amp pedestals, realize that with just one of these puppies running, you won't be able to have a single other item on in your coach while it's working if you are on a 30-amp pedestal.

FWIW.

-Sean
http://OurOdyssey.BlogSpot.com

[Oonrahnjay]

(snip)  with just one of these puppies running, you won't be able to have a single other item on in your coach while it's working if you are on a 30-amp pedestal. 

Will a 30-amp pedestal* even support one of these 29-amp units without popping at an awkward time - even if you have everything else turned off?

(* at least, most of them, in the real world)

[wal1809]

I like what Sean has to say.  My shower runs greater than 2 gals per minute.  I don't have first hand knowledge of these heaters in a bus but I have one in my home that feeds all hot water outlets.  I turned on all the hot water faucets at the same time and used a stop watch and a bucket marked for gallons.  At the end I tallied my total hot water usage per minute and bought a heater according to that number.  It works very well and I never run out of hot water.

The other you need to look at for the temp is the water temp going into your unit.  I had to adjust because I have a 400 foot well at the house.  That water is so cold it will shrivel your pod.  So what I am trying to say is if you live in Texas and buy a heater adjusted to normal Texas water temps and you go to Colorado, your 2 gpm heater may not be able to produce anything more than warmed water.

[5B Steve]

  PP, check with Tom C, if I recall, he has two 10 gal heaters connected together and always has enough hot water

  for when ever he needs it. Tom if you read this and it's not correct I apologize.


   Steve 5B.....

[Sean]

Will a 30-amp pedestal* even support one of these 29-amp units without popping at an awkward time - even if you have everything else turned off?

If they really draw a full 29 amps, then you can expect it to work on a 30-amp circuit for a few minutes.  30-amp circuit breakers are supposed to trip at 24 amps over a period of hours, and at 30 amps over a period of a second.  In between those numbers is a curve that looks more logarithmic than linear.  At 29 amps, you can expect anywhere from one to ten minutes, depending on breaker.

That said, I've had breakers that would trip on 95% load in less than a minute, and ones that would support that amount of load almost indefinitely.

Remember, too, that breakers are rated at 77° -- any ambient temperature higher than that will reduce the amperage the breaker can carry before tripping thermally.  Since you still need hot water even when it's 100° outside, you need to account for this.  I would expect a device drawing 29 amps to trip a 30-amp pedestal breaker in less than a minute under those conditions.

-Sean
http://OurOdyssey.BlogSpot.com

[Lin]

We had a propane instant water heater in our last bus (Paloma).  It did work fine even though you had to get the flow right.  I would consider something like that again.  However, we now have a 10 residential electric water heater, and it is quite acceptable also.  It takes less than an hour to bring it up to temp, which we set high so it will go further.  Also, it keeps the water hot enough for many hours even after it is turned off.  On our last trip, we did mostly dry camping.  I ran the generator for an hour in the morning and again in the evening to top off the batteries and heat the water.  Usually there was still usable hot water in the morning, but of course, this is summer.  One could also time their showers, etc, to coincide with the generator run time to get the most out of it.  If you are plugged in at a campground, you can even turn the water heater off once it is up to heat (we have an interior switch) to free up energy capacity for something else.  I don't think the water heater is a necessary place to invest in exotics.

[Oonrahnjay]

(snip)  I don't think the water heater is a necessary place to invest in exotics.

True, but I like the idea of reliability and flexibility in a water heater.  (That's why I went for a 10 gal propane/electric/"coil" type.)

I would expect a device drawing 29 amps to trip a 30-amp pedestal breaker in less than a minute under those conditions.

Yeah, that was my guess but I didn't have the solid numbers.  Thanks for the info.

[Lin]

Definitely agree that having propane as an option is good.  For me, it would depend on cost and venting requirements.

[Oonrahnjay]

Definitely agree that having propane as an option is good.  For me, it would depend on cost and venting requirements. 

Yes, important requirements.  In my case, the venting is a part of unit (and the unit fits onto a suitable part of the bus) and I'm already running propane for cooking.  So there's little cost increase in piping for propane (and there's little cost increase in the difference between a unit without propane and with).  Works for me but others' way in good for them, too.

[PP]

I appreciate all the input. I would use a propane water heater in a heartbeat if I had a safe place to mount it. Fortunately, the one I'm still using on AC didn't burn my bus up. Looking at the melted circuit board I can only guess that it was a safety feature that shut off the gas to it before doing serious damage to the bus. My hesitation in using a 10gal AC unit is that I thought they were constructed with a glass interior, and although I do stay off the sidewalks most of the time, sometimes I can feel a jarring pothole pretty good and I would worry about the glass breaking and leaking. Maybe I'm wrong about the construction of them and if this is the case, please, someone correct me. Thanks, Will

[Scott & Heather]

just posted this in another thread, but we just installed a 30 gallon Sears/Kenmore electric (single element) 110V water heater (1650 watt) in our water bay. Works fantastic, haven't run out of hot water yet (even with two hot showers back-to-back 2.5 gpm) and we're currently on 30 amp service and haven't had a single issue yet. FWIW.

[Sean]

.. I thought they were constructed with a glass interior, and although I do stay off the sidewalks most of the time, sometimes I can feel a jarring pothole pretty good and I would worry about the glass breaking and leaking. Maybe I'm wrong about the construction of them and if this is the case, please, someone correct me. ...

I think you have the wrong mental image.  The glass lining of a water heater is not like a glass bottle; it is vitreous glass that has been "baked on" to the inside of the steel pressure vessel.  The water heater tank is still steel, but it has a "glass lining", much like a coat of epoxy.  Even the best glass lining process still leaves voids, and there is almost always exposed steel around the fittings, which is why even glass-lined tanks need sacrificial anodes to keep the steel from rusting away.

These water heaters are shipped all over the country by truck freight -- those linings are pretty durable.  The worst that might happen is there will be some chipping of the lining as it ages.  But nothing you can do by driving around in a bus will put nearly the strain on the glass lining that the simple and routine expansion and contraction of the steel tank will exert under normal use, so I would not worry about it.  And the vitreous glass itself is inert and therefore non-toxic.

HTH,

-Sean
http://OurOdyssey.BlogSpot.com

[TomC]

As Steve 5B said correctly, I have two 10gal electric water heaters-one plumbed into the next with the final one wired through the inverter for hot water while driving (I don't like all the extra coolant plumbing necessary for a heat exchanger).  They have worked flawlessly now since I started the bus conversion in 1994.  Can't beat that record and except for draining when I remember to, no maintenance either.  Not to many other water heating systems can say that.  And I can run the water heaters one at a time off a 20 amp plug if need be.  Good Luck, TomC

[ruthi]

We put one in expecting it to take care of the kitchen. Because of flow, it does not work. I would not recommend these units to anyone. We have one in our house. We thought with us being gone as much as we are, that it would save us money. I have hated it since day one. It took 3 of them and a lot of time wasted talking to the company before we got one to work. I still hate it. It fluctuates constantly. Take a shower, and you have to constantly turn it hotter, then cooler. When I get the chance, I want to re-install a regular water heater. Anyhow, that is our experience. Hope it helps.