TANKLESS VS TANKED WATER HEATER AGAIN

nysono · May 23, 2012, 07:49:41 AM

Im looking for real life experience from those that have either tank or tankless. Im trying to go with one that requires NO electricity and can be direct vented horizontally ( I dont want to go throught the roof). Water requirements are low (shower/sink, 2-3 people) and water from well is 40-45 degrees. Pressure will not be a problem for a tankless. Winter temps are COLD but will be in a basement which I dont think will freeze (didnt last year) Obviously cost does play a role but is not the final determining factor. Thanks in advance for all the help

Squirl · May 23, 2012, 08:36:31 AM

Experience with tanked.

They always seem to leak out of a place you don't expect and when they fail, if you are not there, they can do a lot of damage. The last one I had sprung a leak around a pipe and shot the water up on the bottom side of the floor and exposed electrical wires in the basement. One at a relative's house failed when they weren't there and had to replace the entire floor. They all will eventually rust out. Many people push it until they fail. I usually advocate replacing them shortly after the warranty is up. The amount of water damage they can cause is usually greater than the cost of replacement.

The direct vent tank version costs around the same as the tankless at the big box stores. Tanked version 6 year warranty, tankless 20 year warranty as long as you don't have hard water.

I am sorry but I do not have personal experience with tankless yet. Most complaints seem to be when people undersize them for the flow rate and you can get a shock of cold water.

I looked at many categories in my comparisons. When building from scratch, tankless won in every category. Cost, installation, longevity, energy efficiency, and risk. The only test I have not been able to test for was comfort.

May 23, 2012, 09:25:32 AM

thanks for the info,,,I am leaning towards the tankless but was looking for some real life experiences from both sides, so again thanks for the comments..

alex trent · May 23, 2012, 10:25:42 AM

I know you wanted non electric, but for some background...

I have two electric tankless in my house. All three years old. Working just fine. Mid size 220 volt. Mfg. is Titan..made in USA, diet. is in Miami. Had three others in a bar I owned and only have a bit over a year with them as sold the bar.

They also make a 120, which needs to be used with no cold in the tap mix and give reasonably worm water.

Under sink in kitchen and in bath and the one in the bath also does the shower.

Hot is instant..about as long as it takes to get from heater to tap. Mine are adjustable heat control. Have set just a bit over midpoint and will burn you with no cold water.

After using these, cannot understand why we need any tanks.

People here with gas water heaters are not happy...sample of only 3 though.

AdironDoc · May 23, 2012, 10:47:42 AM

Nice to hear from you again, buddy! Hope you're enjoying life up in Tug Hill. Anyway, to the point, I'll give my experiences thus far. I bought two EccoTemp tankless propane heaters for the camps. Keep in mind, they are an economy brand, and perhaps I got what I paid for. As the temperature and flow regulator were on the unit, I found I had to run around back and forth turning the dial until the water temp was acceptable. The failings of my unit became most apparent in the late fall as the days got cold. Initially, the water would be freezing, followed by too hot. Adjust again. Cold again, then warm. Ok, but by the time I finally showered, I had wasted plenty of the water contained in my 50 gallon barrel, graced my neighbors with running back and forth in a towel, and gotten dirty feet!

.

I added a direct line from the pressure pump to the cold water faucet to alleviate this and set the heater to max. Now, no need to adjust outside, right? Nope. Unfortunately, it resulted in wild swings in the heater's output temp. I reason that on opening the cold supply even slightly, the flow rate through the heater drops, causing a temperature change. Frustrated and with winter approaching, I drained both units as per instructions. Both froze nonetheless, destroying them both. At least it concluded that project.

To be fair, I've just bought a Rheem 64DVP for just under $700. It's a higher end unit with an automatic temperature regulator. It's twice the price of the others but is said to be freeze-proof and easy to operate. I'm a bit skeptical at this point, but haven't much choice. We'll have to see how it turns out in the end. I'll also be following this thread with interest.

Have a good Memorial Day weekend (official start of our cabin season?

). Cheers!

Doc

May 23, 2012, 11:00:31 AM

thanks for the info Alex and Doc. Electric is really out of the question, I dont want to run a generator whenever I want hot water, I did think about it though.

Doc, is your Rheem "electricity less" i.e pilot or 9v battery start?

Happy Memorial to you too. Ive been in camp quite a bit working on things.... I need to get some pics posted soon but home computer is fried and is not a priority to fix right now.

Steve

AdironDoc · May 23, 2012, 11:21:08 AM

Steve, the Eccotemps had battery ignition. The Rheem's need 120V for ignition and a small vent fan that runs while the unit is heating. Fortunately, the power inverter and batteries are only a few feet away in my basement.

Glenn

alex trent · May 23, 2012, 04:27:20 PM

I am not selling electric heaters.

But if you have power from batteries, there are heaters that will work without the generator...draw 15 amps. Short (but nice warm..even hot) showers would not be more than a decent setup could stand.

flyingvan · May 23, 2012, 06:10:35 PM

I have four properties---2 have Bosch Aquastars, my home has an electric tank, and the beach house has a natural gas tank.
The bosch aquastars are good performers. You can't tell any difference in use---even with the kitchen faucet on low flow and warm, it kicks out the hot water. There IS the issue with the 'cold water sandwich'----if you shut off your shower to soap up, then turn the water back on, you'll get the hot water that was sitting in the pipe, the little bit of cold water that flowed before the instant on heater came on, then the freshly heated water. It's a few seconds only. Also, the water in the copper jacket likes to freeze---my housing is insulated and I got the pilot light model thinking it would be enough to keep from freezing---no luck. If I know cold weather's coming I put a 15 watt bulb inside the housing and hope the power stays on. If I'm there, I just run the water every couple of hours.
Tankless are also prone to a significant annual efficiency loss due to scaling in the water jacket. If you install a 't' with shutoffs above and below, it's easy to do an annual run-through with some CLR then flush it out a bit. You can use the same 't' set up to isolate the unit for cold weather and just drain it, then you don't have to worry about freezing. Also there's a little air intake filter for the pilot that gets dirty evrey two years or so and needs to be cleaned or your pilot keeps going out. Bosch's pilotless model is powered by water flow so no external power is needed, but I have no experience with that model.
They consume 117,000 BTu's so you have to make sure your gas lines are the right diameter to meet the demand. I get 70 degrees heat rise out of my units----I have to adjust the temp summer vs. winter since my water temp going into the houses varies greatly by season.
So, if you hate fussing with things, get a tank system and just drain it every few years to keep sediment out.

May 24, 2012, 10:27:20 AM

Quote from: alextrent on May 23, 2012, 04:27:20 PM
I am not selling electric heaters.

But if you have power from batteries, there are heaters that will work without the generator...draw 15 amps. Short (but nice warm..even hot) showers would not be more than a decent setup could stand.

The only time you run 15 amp loads offgrid is when the sun is shining. It can be done if you tripple the cost of the system which is pretty wasteful. Anything can be done with a generator and in my opinion that is wasteful except in the new construction phase. I am basing this on a residence and not a cabin or part time.

A gas fired tank with an open loop solar collector is a good way to start. Drain it when the weather gets below 35F and use the gas. Good Luck!

alex trent · May 24, 2012, 10:46:52 AM

You can draw more than the panels produce with energy stored in batteries. That is the point of batteries, is it not? I am assuming he has batteries and not just sun in sun out.

With even a modest system, you can get 15 amps for the two minutes the worm shower takes.

Aside from not having to fool with gas and tanks and gas heaters, which her their on issues, this is a very environmentally friendly way to do it.

You do raise a good point in the solar hot water system. Could give hot water for several months without anything else.

100 feet of place 3/4 inch hose in the right place will give you all the hot water you need most days in the summer, and more than a few in the spring and fall.

Dave Sparks · May 24, 2012, 11:17:18 AM

In practice the batteries get discharged from large loads and then they get damaged. Large loads are run on large battery systems. Modest batteries with large amounts of solar are how most people run large loads during daylight.

If it was just 2 minutes a day then I suppose it would work. It never works out this way in practice. I am on my 51st offgrid home consult now and I just stay away from advising large loading of batteries because I want them to last over 10 years.

In the end offgrid, you are either energy supplementing with propane or deeply cycling batteries. Both methods can be expensive and have their environmental costs. It is all a matter of balance and there are always exceptions. A location in the southwest US or similar climate can really open opertunities for running 100% off the sun.

alex trent · May 24, 2012, 12:04:03 PM

1. Batteries also get discharged fro small loads over a longer time and the same damage results. So, in this one needs to make the assumption that the system is designed used correctly. If you do not make this assumption, the entire discussion doesn't make sense anyway.

2. Larger loads can be run on modest battery systems for s short time with no adverse effect...as long as you keep #1 above in mind. Calculate how much 15 amps for two minutes is. With a modest 300 AH battery system and a reasonable number of panels, that is easily doable. Of course, if you are trying to recharge just with solar and using a 150 watt panel, you have some issues. Goes back to having to make decisions at the outset. Without hot water or a fridge, you might get by, but add more and you need more. Pretty simple concept. As with everything there are variable...if the summer monsoon blows in and it is cloudy for 4 days, you are out of luck, but that is the exception not the rule if the system is planned correctly. In this case, you plan for the usual, not the unusual..just have to put up with the unusual, or build a lot bigger. Better to put up with anomalies.

3. You can take a very nice shower in two minutes of water. Wet down (30 secs), water off; soap up (sing if you wish...no power required); Water on to rinse for 90 seconds...that is plenty. I am not sure how you can say "it never works out this way in practice". But, nevertheless, if people abuse the system, that is another issue...revert back to #1 for that.

You design for 10 year battery life. Great. But if I can have my hot shower in a simple, environmentally sound way, for eight years of battery life it is likely worth it to most. At a shower a day, the cost is less that a dime more, not counting the4 saving on gas...heck I think it is actually a savings when that is figured in.

Dave Sparks · May 24, 2012, 12:54:51 PM

Let us just agree to disagree on how nice a 2 minute shower is! I know my clients would not be happy with that!

May 24, 2012, 01:07:50 PM

Quote from: Dave Sparks on May 24, 2012, 12:54:51 PM
Let us just agree to disagree on how nice a 2 minute shower is! I know my clients would not be happy with that!

Any quicker it would be called dry cleaning

alex trent · May 24, 2012, 01:08:36 PM

You are right. I forgot that you have to understand what people want when you design...unlike when you just do it for yourself. I have another reason for 2 minutes, I collect my own water and have a 5 month dry season.

Of course if you take your girlfriend in the shower with you, time flies.

That said..try it sometime, you can get clean.

waggin · May 24, 2012, 01:33:29 PM

I have an older (10+ years) propane Aquastar with flow triggered battery ignition, and I'll rate it as ok. It uses two D-cell batteries, and they seem to last quite a while. Some of the fittings are non-standard and are of a sketchy design in terms of sealing positively. On the supply lines, there is a copper tube with a rubber washer that presses against the sharp end of another fitting that has threaded flats on the sides.

While showering, the temperature will change if the pump kicks on, as it will be getting water straight from the well vs. from the pressure tank. Fortunately, this isn't horrifically different in my case. Mine is turned almost all the way up, and I shower with almost all hot water with very little cold.

That said, my plumbing system is a bit of a mess, and I intend to redo it sometime this year. Location is in the utility room (inside) and venting is through the roof. Last year I replaced the electronic control module for about $100 in parts after a helpful tech call where the tech guided me through the troubleshooting process with a multimeter. In this day and age, it's impressive when a company will have a tech person stay on the phone with you and guide you through the troubleshooting process.

It was here when I bought the place, and once I replaced some odds & ends while saying all sorts of not so nice things about its ancestry, it does the job well enough. Overall, I'm satisfied. I haven't looked closely at the newer ones.

MountainDon · May 24, 2012, 04:01:19 PM

Never saw any mention of temperature rise in discussing a tankless heater. That can be a factor with some cheaper units.

On the subject of drawing 15 amps for some electric use and being off grid... My off grid experience has been that frequently system use grows to unplanned levels with many folks off grid systems. My use grew but there was a big cushion provided in planning. I think that part needs plenty of thought before buying any equipment.

While I can and do take short low water use showers, my wife, who unlike myself has a full head of lovely hair, can not.

There is much to be said for using as much solar as possible for heating water. But then being in the SW like we are it could be easier than in some locations.

As for a tank being a potential leak problem that can be headed off to a high degree by paying attention to periodic draining off of sediment and a replacement schedule. We own some condo rental properties. The association owns the water heaters, furnaces, etc. They replace the equipment on a maintenance schedule and in the twenty years I've known the maintenance supervisor I know they have never had tank leakage. We do the same thing here at our home. Replace before there is a problem. Some may think that wasteful and prefer to eak out every last minute of use. Penny wise, pound foolish, in my book. We like the idea of a well insulated tank type solar assisted water heater.

nysono · May 25, 2012, 05:43:20 AM

Thanks for all of the input from everyone. I am leaning heavily towards a tankless system. Solar power is not an option at this time for me due to location/trees and cost. I will update this thread when I get a final install set.

flyingvan · May 25, 2012, 07:59:58 AM

You can always get a used tanked water heater later, strip it down to just the tank, and paint it flat black. You can mount it outside in direct sun and have it feed your tankless pre-solar heated water. You just install it with bypass valves so you can leave it empty in winter

Dave Sparks · May 25, 2012, 09:42:03 AM

Quote from: alextrent on May 24, 2012, 01:08:36 PM
You are right. I forgot that you have to understand what people want when you design...unlike when you just do it for yourself. I have another reason for 2 minutes, I collect my own water and have a 5 month dry season.

Of course if you take your girlfriend in the shower with you, time flies.

That said..try it sometime, you can get clean.

I lived on a sailboat all over your part of the world for 3 years. Beautiful tropical lifestyle! Ditto on the rain water for 20 years now. I do miss the Flora de canya rum..... Take care!