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View Full Version : Anyone using propane tankless hot water heater??



LogHomeFeverDan
12-12-2012, 06:36 PM
And have some feed back? I've been looking at them.

Waiting for March and the class but looking at all options for the log home. We'd like to cut down on all the heavy users of electricity. We'd really like to have an off grid system but it just doesn't make economic sense yet with batteries unless I can find some telecom batteries like Rod has mentioned. We'd like to go propane for as many appliances as possible. Always wanted to have a commercial griddle with a couple of burners and deep fryer on an island in the kitchen. Researching rocket mass heater and or geothermal. Still have to figure out the clothes dryer and with my lovely wife and two daughters, well even the female dog and cat, we MUST have hair dryers. (snicker) Think I can rig up a solar powered hair drying station???? <full body head tilt>

Anywho, I digress. Seems the most common "con" to tankless is the delay in arrival of hot water. I don't know I've always had to wait for hot water. I've heard some folks put in a very small propane hot water heater to avoid the delay, like a four gallon heater.

While I'm on the subject anyone plumbed with pex? Seems it would be easier as less connections. Not sure how the manifold would work but it seems easier.

Ready for feedback.

Mosseyme
12-12-2012, 08:46 PM
check out the Eccotemp tankless water heater, haven't bought one yet so can't give feedback, but intend to get one of the small ones [prob. the L10 ] soon for our little shack so we can decide if we want that for the cabin.

http://www.eccotemp.com/

sdart
12-13-2012, 01:08 AM
The delay for any kind of water heater is the same if the pipe distance from the water heater to the faucet is the same. Either way, you have to get from the device that is heating the water to the outlet where you want the hot water to exit. We have used tankless propane water heaters for years and have found that the hot water is available much more quickly than in any house we have ever lived in with a big hot water tank. But that is probably because the tankless heaters we are using now are located in the bathrooms and the big tank was always in the basement, further away from where the water was needed.

WNYcabinplannin
12-13-2012, 08:26 AM
Ditto on distance n pipe size for water delay. Pex rules. I've never done copper plumbing and I did my whole cabin with pex easily. I did a Navien combo unit bc we did radiant in the basement. Awesome, but you could get a much less $$ unit just for domestic hot water.
Random note- I had my plumber run a half inch line outside so ill have hookup for the grill- no more tank changes ;)


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LogHomeFeverDan
12-13-2012, 09:39 AM
Thanks for the input all. Seems the delay for hot water isn't that big a deal. WNYcabinplannin, I assume you are speaking a gas line for the grill? Did you need the plumber to do that? Or was it a code thing?

StressMan79
12-13-2012, 10:13 AM
I just saw an episode of ask this old house, and code requires a "certified gas fitter" to run lines.

WNYcabinplannin
12-13-2012, 10:28 AM
Installer of the Navien was licensed and insured. Had 3 things to supply. TWH, LP gas range and my exterior grill. 1",3/4"&1/2" respectively. Grill needed custom hose to quick disconnect that doesn't have regulator as the cabin has big one at connect point (set at 12.5" of water count) I had no idea how LP/ water count worked before I started.
If one is doing an LP TWH, plan ahead for any future addons. He only charged me $20 for the extra hardware to do grill. ~1$/gallon from LP company vs 4$ and hassle of replacing BBQ tanks. :)


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StressMan79
12-13-2012, 10:29 AM
oh, and if you need hairdryers, they will run on DC (DC fan motors and a resistive load), also CFL bulbs first rectify the input, so DC is fine for them too... (of course LED lights will work on DC. You just need more of them in series)

The kicker: you need ~120 VDC to do this, and that high of DC voltage has big problems with arcing (anything > 50 VDC, according to UL), so you need more batteries, and there is only 1 charge controller for this system voltage (http://www.gogreensolar.com/products/midnite-solar-classic-250-250vdc-mppt-charge-controller?gdftrk=gdfV21109_a_7c323_a_7c2152_a_7c4 2947412), and you need non-standard DC breakers and switches throughout. where you have 120VDC outlets, you need a separate type of outlet, that you can't put a standard plug into...

Lots of work, but hey, I almost did it!

lilbluehonda
12-13-2012, 12:34 PM
One nice thing is square D has a line of breakers that work on AC and DC and you can use there breaker boxes that are far cheaper than the ones you get from the solar supply places and you can get them at Home Depot

rreidnauer
12-13-2012, 02:04 PM
I just saw an episode of ask this old house, and code requires a "certified gas fitter" to run lines.

Unless things have changed since the 90's, thats a load of bull. We use to install black iron gas pipe ourselves when I was an electrican/HVAC installer. Cripe, it's far from rocket science.

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LogHomeFeverDan
12-13-2012, 02:37 PM
I really like the quick disconnect idea for the outdoor grill. I'll probably end up calling in the professionals for gas line install. It'll be enough to get my confidence high to do the electrical and plumbing. PEX sure looks easier though.

Stressman thanks for your insight. I've not really considered going dc yet. Have always looked at inverters for ac. No matter how you slice it, unless I'm missing something it's still not economical to do a completely off grid system. Of course the biggest barrier to that for us is our land already has underground utilities. Former developer went under after they installed underground utilities on all the lots in this 155 acre parcel. Funny, actually, we have super nice paved road to get to each lot, but need to take a gravel road to access the property. We've not been up there when it rains hard but the turn off from the main road is gravel through a small valley with a creek, thus the potential to be flooded out. Oh well when we get set up to be self sufficient getting flooded at the access road won't matter. (-;

Still tons and tons to research. Sometimes you folks rattle stuff off that goes so far over my head it might as well be a foreign language. I've seen Rod talk about subjects that I have to google about every fourth word . I mean I fell off a turnip truck but it wasn't last night, and I did go to kollig, I evan are a gradumate. I sometimes have challenges with electrical topics however.

Always appreciate the input from everyone, it provides impetus to learn.

StressMan79
12-13-2012, 05:09 PM
there are two, and only two reasons to go off grid:

1) you want to, either b/c you think the dollar will crash, or you just want the experience.
2) you have to, I live a mile from power, the cost would be prohibitive.

Even if panels were free, it will cost you more/kwhr to go off grid. I have heard something like 30cents/kwhr. when you can buy it premade for you for 10cents, you do the math...and living off grid is more difficult. No power company there to make your stuff work. you need panels and a genny...Propane stuff is more spendy than the same electric stuff...

Kick Forward
12-13-2012, 08:57 PM
I remodeled a lot of our last home before selling and ran all pex for water lines. It was so easy it was borderline fun.

sdart
12-14-2012, 11:34 AM
We have been using a small, propane tankless water heater that does not need a pilot light and so saves quite a bit on propane. This is appropriate for places like ours that are off the grid, because the ignition is generated by a mini hydro system that uses the water flow to spark the ignition, so no house electricity needed to start it up. Very cool and it works beautifully. In addition, it doesn't need much water pressure to run, which is great for us because we are getting our water by gravity-feed from a spring just high enough on the hill to work… but the pressure we have is not enormous. The heater we use is, unfortunately for most on this forum, made by a company that doesn't seem to do business in the States: E.L.M. Leblanc.

This is the little guy, for those of you who read French. You can download the brochure in a pdf file that gives you the specs interspersed with photos of people taking showers and baths (hey, it's French after all, what did you expect?!):
http://www.elmleblanc.fr/private_consumer_elm/produits/detail_produit/page_produit_2432

I have seen references to a similar one by Bosch that is sold in the U.S. but it seems to get mixed, if not downright bad reviews. But surely this useful technology will be put to good use by some other company? I hope so, by the time we get to that stage of our log home build.

ncgator
12-14-2012, 05:20 PM
Here is an interesting site that reviews different units.

http://www.hvac-for-beginners.com/tankless-water-heater-ratings.html

LogHomeFeverDan
12-16-2012, 07:03 AM
I remodeled a lot of our last home before selling and ran all pex for water lines. It was so easy it was borderline fun.

That comment is borderline scary my friend! ;) I've not ran water lines, ever. I do tend to enjoy learning and doing new tasks. I'd have to believe if I were to choose the term "fun" with running power lines it'd be more apt to apply to a new build than a remodel. My warped sense of humor aside, thanks for the encouragement!

Stressman, yeah we've mostly ruled out off grid. The reason we will incorporate propane is I've always wanted a commercial type griddle on an island in the kitchen. I also want gas burners for the wok. I can't stand using the wok on electric. We are still exploring grid tied systems just to lower utility costs. The one aspect of our "master plan" I still am considering going off grid is the aquaponics operation. We'd like to know even if power goes out or gets spotty we could still grow produce and keep the fish alive. I was up at our property yesterday doing another walk. Unless we decide to move a lot of dirt, the greenhouse will be a distance from our home. Of course the power requirements, even more my final arrangement with aquaponics is much less than a house.

LogHomeFeverDan
12-16-2012, 07:04 AM
Ugh......that should read running "water" lines not power lines. I still can't find the durn edit button.

loghousenut
09-11-2014, 02:15 AM
It's a dead thread so I thought I'd resurrect it in a different direction. It has been 21 years since the Boss and I have moved back "on grid". Before that was a buncha years out in the back country, most of it living kinda in the rough. I went from garden hose showers and bathing in the river, to RV showers in the bus, to the lap of luxury... an outside shower with hot water supplied by one of two different tankless propane water heaters. There's nothing like a good outside shower and nothing like a good tankless water heater.

Well, after all those years of hauling propane and loving every minute of it, when we moved close to civilization, 21 years ago, I just naturally yanked out the electric water heater in the ugly trailer and plumbed in our tankless propane heater. Seemed like a no-brainer. Just because we now had cheap electricity, instead of the free stuff, didn't mean we had to have an electric water heater!

Now, here it is 21 years after going to work full time at the Muffin Store, and 21 years after moving 1 hour closer to work, and 21 years after Jake turned 1 year old, and our second tankless water heater pooped its guts all over the back yard. The company that made it was in France but out of business. I had "fixed" the burner assembly several times but now the main mixing valve was all gunnybagged, so it was time for the scrap heap.

The log home will NOT have a tankless propane unit simply because the water heater will sit right next to the center RPSL and I wanted to make the plumbing easy so I know it will be electric. Why buy a $1,000 tankless heater when I may accidentally finish the log home some day and then go out and buy a cheap electric model.

So I bought a cheap electric water heater. I mean really cheap. It is a 40 gallon "mobile home model" so it is as cheap as they come. Wire it up and bend a few water lines and I am ready to go just like all the other trailer trash in the valley.


So my main question for the rest of you is this... Why did I wait so long? This water heater is amazing! I didn't need a water pressure regulator on this heater so when I turn on a hot water valve I get full, non-metric, 100% American, waste it or lose it, honest to goodness full strength hot water! That means that doing dishes involves fairly quick hot water and a lot of it. That means that a shower feels like a back massage! I love this water heater!

I know this is a radical departure from where this thread was headed, but I just wanted to say that, for those of you that have 220v of city power, you could do a lot worse than an old fashioned electric water heater. Save the extra money to invest in hand forged door hinges or underwear. I want photos!

rreidnauer
09-11-2014, 08:14 AM
Hand forged, hinged underwear?

I want photos too!

loghousenut
09-11-2014, 08:48 AM
Darned Photobucket child lock has my hands tied on this one. Your imagination will have to suffice.

kahle
10-18-2014, 01:32 AM
We installed a small Bosch tankless heater mostly because we walk away from the cabin in the winter and let it freeze. It's a lot easier to drain a tankless heater than a tank. This is a propane model with a pilot light. I only have about 30psi in my water system and it is the drop in pressure across the unit that turns on the burner. As a result we've had some interesting adventures with the "cold water sandwich".

As you throttle down the water flow across the heater (like when you are adjusting the temperature of a shower, for example), if you happen to drop below a minimum pressure drop, the heater turns off. And when it turns off the warm goes cold, not luke warm, but cold. And if you turn it back up, you have to wait again for the hot water to push that cold water out of the line.

But it sounds worse than it is. Once you know about it, this rarely happens. And there's an advantage to have an unlimited supply of hot water any time you want it.

rreidnauer
10-18-2014, 10:35 AM
Yea, IIRC, user manuals say to fully open the hot valve, and temperature control with throttling the cold valve. I suppose if you have a shower head with a flow rate above the capacity of the heater, you can control temperature by throttling the hot valve alone, by fully opening the valve and then closing it a bit to increase temperature.

With that risk of cold water slug in the water line, it's a good arguement to locate the heater as close to the shower as possible.

Mosseyme
10-18-2014, 10:46 PM
Yes the cold water can happen, we have a 6' hose from outside through the wall to the shower and that is long enough. We have a double valve with a shower head on one and just the open pipe on the other, if the water is to cold from the pipe you can switch to the shower head and it slows the water down enough to make it hotter without decreasing the pressure enough to drop the heater.