Tankless WH

[kmcmahon]

I am upgrading my water service piping in my home to PEX and had a local plumber over today for an esitimate and I mentioned to him that I would be also upgrading to an on demand tankless water heater...he just looked at me and grinned. "I've put in 17 of them things and taken out 15" he says.
He said the problem stems from sediments. With a tank you get sediments at the bottom of the tank...no big deal, but without a tank the sediments deposit and clog the coil.

I have not as of yet gotten to inspect on of these tankless heaters, but I am looking at ways of reducing my home energy bills and have seriously considered them, but now I am rethinking that.

Anyone got any insight into these tankless systems pro or con?

Thanks.

[Michael Larson]

Ask him how many of the 15 had soft water.

Soft water does not produce hard sediments.

[Larry D. Kage]

I've not heard of that problem. People I know have had them for 5 years or more and love them.

If your area has excessive minerals, etc., I wonder if a filter of sorts would be cost effective?

[John J. Passailaigue, Jr.]

I have one in the new house that I live in now and have had no problems My gas bill is a lot lower than at my other house. Cut it in half! So far I love it!

[Michael D. Thomas]

I have 5 - one at home and four at rental properties.

No problems so far (4 years).

They are usually not energy savers though:

http://www.nyletherm.com/whitepaper2.pdf

I use them in rental rehabs as in my urban market every sq/ft of habitable rental space is gold.

[Michael D. Thomas]

For those not familiar with tankless units I finally got around to pulling together all of my various posts WRT my experience with these water heaters:

http://paragoninspects.com/home-insp...blems-faq.html

[Doug Edwards, CMI]

I have inspected a number of them and no one has ever mentioned a sediment issue and in fact they all loved the tankless units. There are probably half a dozen easy solutions to sediment, depending on it's source. If for instance it is coming in from the street service, filter it to remove sediments. Google will most likely have a zillion hits to look for solutions.

http://www.pse.com/solutions/homePDFs/TanklessWH.pdf

[bzimbelman]

Originally Posted by kmcmahon

I am upgrading my water service piping in my home to PEX and had a local plumber over today for an esitimate and I mentioned to him that I would be also upgrading to an on demand tankless water heater...he just looked at me and grinned. "I've put in 17 of them things and taken out 15" he says.
He said the problem stems from sediments. With a tank you get sediments at the bottom of the tank...no big deal, but without a tank the sediments deposit and clog the coil.

I have not as of yet gotten to inspect on of these tankless heaters, but I am looking at ways of reducing my home energy bills and have seriously considered them, but now I am rethinking that.

Anyone got any insight into these tankless systems pro or con?

Thanks.

I personally know of six that are in use. All in friends homes who live in my neighborhood. All have well water, none have a water softener, most have a gross filter on the incoming water, none have any further filtering and none have had any problems with the tankless units(with the exception below). I think the youngest is two years old, and most are over four years old.

One friend's unit has to be reset frequently, it has always been that way. I'm almost certain they didn't configure it correctly, and have suggested that it could be fixed to not have that problem, but they seem to think it's not a problem, and who am I to think things should work as designed???

As for costs of operations, all of them have told me that they have reduced their gas bills, but only two of them replaced a tank water heater with the tankless in the same home (others were installed when they built a home or added on or...), and since most of them heat the house partially or fully with gas, not sure how they could back up that claim.

I do know of one who is off grid, heats by passive solar and wood stove, gas on demand w/h and stove which are run off propane. He has a 150 gallon tank, and he fills it once a year. I think he told me he only needed 80 gallons last year. So it can't be too bad efficiency wise.

I will say that a couple of my neighbors had issues with sizing the units properly. Everyone out here has a well, and many of them are poor producers, so most of us have cisterns (500-1500 gallons), usually a black poly tank sitting outside somewhere. In the summer the water can get fairly warm, in the winter it can approach 35-40. So, if you wanted your hot water to be delivered at 105 say, then you would need over 60+ degree rise in temp at whatever rate you need for your family. However, the other eight months or so, you may only need 40 degree rise in temp.

This is only a problem for us country folk, city water dwellers, generally do not have a concern about this as their pipes are (or better be) buried deep enough for them to have very minimal variances in temperature delivery from winter to summer.

There are a number of solutions to this problem that my neighbors have come up with. They range from moving the pressure tank into a heated space to building a solar hot water heating panel, and of course one simply bought the larger unit, and traded a little in efficiency for the guarantee of HOT water!

Hope that helps.

-- bz

[rwand1]

It would be inexpensive to place a sediment filter to the incoming water line. Even municipal water will contain some sediments.

[Doug Edwards, CMI]

This is one I did last month. Thought the data tag may be of some help with parameters. Of particular interest is the rate of recovery (193 gals/hr).

[Thomas H. Dietrich]

I was going tankless. I told my plumber money wasn't an issue, since I had it upfront, and the tax break was a plus. He said, wait and research it. I am not interested in tankless anymore.

1. Many residential gas systems aren't sized to the water heater for a high demand source. So I need to upgrade my gas lines.

2. Living in the north, unless I go to a 3+ appliance rating heater, I would have problems operating just 2 in the winter.

3. The concept of opening the hot water handle in a tub, actually decreases the temp, was too confusing.

4. Even with the tax break, the increased cost of installation, increased cost of equipment, it wouldn't break even for a LONG TIME. It seemed beyond my life expectancy.

I re-evaluated my needs, and I really just need a larger, efficient tank heater. Biggest motivation was my 38 gallon tank didn't stand up to my wife taking an "hour shower." For a 4 bed, 2.5 bath house, it's undersized.

imho,

tom

[Douglas Cossar]

I have a tankless unit in my home.

Installed in May 2005-- never had a problem, oh yea.... July and August gas bill was $12.00 tax and everything else aded in.

Never got below $50.00 before

Cheers

[relliott]

If I ever installed one my bill would go up just because I would spend all day enjoying the endless supply.
For myself the issue is not saving energy as much as not having to wait for the tank to reheat.

[rcooke]

Originally Posted by dcossar

I have a tankless unit in my home.

Installed in May 2005-- never had a problem, oh yea.... July and August gas bill was $12.00 tax and everything else aded in.

Never got below $50.00 before

Cheers

Shower together save even more.
Try it, works for us .

.... Cookie

[Brian A. MacNeish]

Originally Posted by dcossar

I have a tankless unit in my home.

Installed in May 2005-- never had a problem, oh yea.... July and August gas bill was $12.00 tax and everything else aded in.

Never got below $50.00 before

Cheers

How many people in family and........how much time did you spend at the cottage or away on vacation........virtually impossible for a family to have $72 DHW bill per year these days with normal use.