Water Heaters - Water heater configuration for adding second bathroom

The start of my project to add a second bathroom is 1-2 months off now, but since I have a 10% off coupon up to $2000 at Home Depot that is good this weekend only (and excludes lumber and building supplies) I might be buying some of the stuff now, that could include the water heater.

Right now, I have a 40 gallon gas water heater. It's about 6 years old, I have no complaints or problems with capacity right now. Usage is for a dishwasher, washer and a bath/shower, right now it's just my wife and myself with a kid on the way.

What we're adding is a second bath with a shower stall plus a whirlpool tub, the tub comes with it's own "EZ heater" apparently.

I'm of the opinion that initial cost aside, my best option would be a tankless water heater. Is that probably true, and if I were going that way would it also be best to just hook in the existing hot water plumbing to it as well?

Due to over-runs and unexpected additional expenses beyond the margin for error I had planned for, I might have to use a regular tank water heater, and unless there's a good reason to go electric, I would plan on that being gas.

That being the most likely direction, which way should I go?
1) Get a larger water heater to replace the existing one
2) Get a second water heater to supplement the existing one
3) Get a second water heater to support the new plumbing on a seperate hot water circut

Even more basic... Considering that even though I'm adding a bathroom, I'm not increasing hot water usage except possibly from the whirlpool tub... But since it has an "EZ heater", do I even need more water heater capacity?

One thing that makes a difference is how close the new bathrm. will be to

the original bath and how much farther away from the water heater.

A 40 gal. heater is usually adequate for 2 bathrms. Most people will go to

a 50 gal. for a wirlpool tub. I don't have any experience with the built-in

heater you mentioned. If you have untreated well water (you didn't say)

then the tankless is not a good option. If the new distance is too great

between water heater and bath, you can install a circulation pump from

the water heater drain valve (available at HD also) but once again, not a

good option with untreated well water. Another thing to consider is the

possible life expectancy of the existing water heater. Estimating that is

mostly guess work, but if you happen to have a mechanic's mirror on a

flexible extension and a good flashlight, you can look at the tank bottom

from the same access that you would use to relight the pilot. Some

corrosion should be expected, but heavy scale and signs of leakage would

be a good sign you need to go waterheater shopping.

Here's a link for the whirlpool heater:

http://www.homedepot.com/prel80/HDUS/EN_US/diy_main/pg_diy.jsp?CNTTYPE=PROD_META&CNTKEY=Products_2%2FKitchen+%26+Bath%2FShower+%26+Tub+Access.&MID=9876&ProductOID=529527&cm_ven=1hd.com2yahoo&cm_cat=shopping&cm_pla=prod&cm_ite=prod

It looks like it is intended to maintain temperature, my best guess is it wouldn't make up for running out of hot water.. I'm pretty sure my current water heater is in decent shape, I wouldn't otherwise need to replace it.

I was kinda thinking that the whirlpool, more than anything else, would be the driving factor in needing more water heating capacity. What I'm getting has a minimum operating volume of 71 gallons and a volume of 86 gallons to the overflow.

I have city water, and the distance will be about 20-25 feet from the water heater to the new bathroom... The current one is right on top of the water heater, if the toilet fell through the floor it would land on the water heater.

I think I'm leaning towards just staying with what I have right now. If I got something now, it would probably be an incremental upgrade, and what I'd really like is to just upgrade to a tankless water heater.. I think the best route is going to be to just skip the incremental upgrade altogether and get the tankless water heater if either the capacity isn't quite enough, or when the current water heater needs replacement.

I would go with #3. Tankless is a BAD choice if tubs ( as opposed to showers) are involved. The initial cost to get enough flow to fill a tub is very high, and most poeple are going to be surprised by early failure of their tankless due to lack of semiannual de-scaling maintenance.

Putting in a second tank, close to the whirlpool, solves both the capacity and time-dalay (water-waste) issues.

Id go for #3 also if you can get a flue pipe out there for it.All you need is a B gas vent pipe.

ED ;)

Hmm.. I think for my situation, after looking it over a bit more, time-delay isn't really a consideration. I'd have a run of 20-25 feet from my existing water heater to my new bathroom and whirlpool. Given that I would have to put any water heater in the basement, and given the available space, I don't think I could reduce that by much more than 6 feet.

Aside from that, the distance is comparable to what I have currently for distance to the kitchen sink, and if that's an indication of the time delay I'd be facing, then I would consider it a non-issue.

But in terms of operating cost, I'm not sure if water cost is more of a factor in other parts of the country, but I don't think if water as a major cost, but gas is another story... And having 2 water heaters sounds like something that would drive gas costs up.

With a baby on the way, maybe there are other considerations as well... I think there is no doubt in my mind that I can finish the project and have a system that will be adequate for my wife and I. However, it will probably require keeping the water heater at max temperature so I can fill the whirlpool with, say 50/50 hot and cold water or something... But for the safety of the baby, I know that it's better to not have the hot water heater cranked all the way up.. It would be better to have a hot water source that could be at a lower temperature hooked up to where the baby's baths are going to be...

And in the longer term, it's going to be 3 or more people taking daily showers and/or baths.. That which is adequate capacity for now might eventually not be adequate.

Thanks everyone for the input.. I've certainly had questions answered, but I've also got more questions. I'm still going to go with the approach that I'm going to stick with what I have, I'm going to use my coupon on other things, and I'll make a decision on upgrading my water heater capacity once I have the bathroom in and can see what I might or might not need based on what really happens.