Tankless water heater?

[overland]

We're in Chicago, and our old gas water heater is starting to leak. We need to replace it. We thought about perhaps going tankless, although I don't know if it makes sense this far north, especially considering the additional expense. Any thoughts or experience with these?

[JosephP]

We looked at doing that, but ruled it out because of the upgrade needed to the gas line.  Didn't even get to the point of trying to figure out venting (water heater on internal wall... current vent through roof so that probably needed upgraded too).  I was willing to spend a few hundred extra for the heater, but the install would have added thousands.  I like the idea and reviews.

[MT Woodworker]

We have a gas fired tankless
Would not go back to a regular tank.

[jteneyck]

Every time I've looked the economics just don't make sense for tankless.  As said, the need for an increased gas line and maybe meter, too, and figuring out how to vent it, on top of the price increase for the tankless unit over a conventional unit just never made sense over a reasonable lifespan.  The cost for hot water with my 40 gal tank is less than $25/month.  Even if a tankless cut my bill by 1/3, which is a big stretch, that's an $8 savings.  If the price difference between conventional and tankless were only $1000, and it's more, It would take 125 months to break even.  

John

[MT Woodworker]

We were fortunate, already had gas line and venting in place

[Scouter]

We went with one three years ago and would never go back again, the fuel savings has been tremendous. At this point, in the non-heating months, we are charged the gas company's minimum charge.

If you have a gas water heater now you're not going to need additional gas line or service, this uses less than a tank water heater. If you don't have a gas water heater there are electric versions as well.

The only maintenance has been flushing the heater every 2 years with either vinegar or CLR, plenty of videos on the web to show you how to do it, it's not difficult.

[Kudzu]

We were going to put one in our house we are about to build but my wife realized that if power is out, you have no hot water. A standard gas water heater with a pilot still works. 
We live in Tornado alley and have gone a week without power yet we had hot water and were able to cook (gas).  Neighbors gathered at our house because they were all electric. The small saving for just the two of us is not worth it.

[EightFingers]

Doesn’t take much of a generator to run a tankless (gas) water heater.

[DieselDennis]

It's not about making cents.

It's about LOML having however much hot water when she wants it (and me not having to hear about it !)

I can only think of the anguish I will avoid as my daughters become teenagers.

[jteneyck]

We went with one three years ago and would never go back again, the fuel savings has been tremendous. At this point, in the non-heating months, we are charged the gas company's minimum charge.

If you have a gas water heater now you're not going to need additional gas line or service, this uses less than a tank water heater. If you don't have a gas water heater there are electric versions as well.

The only maintenance has been flushing the heater every 2 years with either vinegar or CLR, plenty of videos on the web to show you how to do it, it's not difficult.

Can you define what you mean by "tremendous" savings?  What percentage are you saving?  

If I were to replace my current 40 gal piloted hot water heater with a tankless I would need to upsize the meter and figure out how to vent the thing, assuming we are talking about a whole house unit here.  My current hot water heater draws maybe 40K BTU/hour when it's on.  A tankless that provides only 3 gpm at 70F rise is going to take around 140K BTU/hr and it's running every minute the water is flowing.  To handle that increased need of 100K BTU/hr I would need a larger meter, at my expense.  Most tankless hot water heaters are direct vent these days, you can't vent them up a chimney, and that would mean more expense.  

Like you, I pay the minimum gas company charge in the summer months - with my piloted hot water heater.  

John