This doesn't have to be a big deal. You can go with a gas tankless and do just fine.

A couple of things to consider are:
-Concurrent water usage in GPM(how many hot water faucets and what type do you want to be able to use at one time?)

-Water inlet temperature. In Tampa, I don't think this is a big issue.

-How easy (inexpensive) it is to vent.

For your family, I would suggest looking at this heater or one similar to it made by another manufacturer. It is near 200k BTU input and is a good value. There are others similarly priced at that size. You should get about 6-7 GPM out of it given your water temperature. That's two showers and a faucet running at the same time.

This one mounts in the wall outside, eliminating venting completely. They also offer interior wall mount units.

The Bosch unit is the only unit that I know of that has gotten bad reviews -- unless they change their design, I would avoid that unit.

There is a $300 tax credit and you should expect to get a 25-30% savings over your regular water heater. Usually propane costs more than natural gas, the dollar amount of saving would be more than a Natural Gas user.

Here is a link that might be useful: Outdoor tankless

Thanks! I've put in a call to my propane company. Having an outside mount sounds great, but if the hot water supply line (and the water softener) are in the garage I guess that would involve the running of lines? Or would we choose to put it inside and just deal with the necessity of a new vent? I'd really like a new vent in the kitchen (which isn't far away) because I want a big bad propane cooktop - any chance they'd be combined and then we'd only have one (extra) hole in the roof?

Jake,

I was reading your post here, and was wondering if you could give me advice on my situation. I currently have a gas powered hot water heater. It is located in the basement of our 2-story home. It heats the water for the front loading washer (in the basement), dishwasher, kitchen sink (both on the first floor), shower and bathroom sink (on the second floor). While the hot water heater seems to work OK (it does leak from the pressure valve for some reason) I have the same problem many others have - it takes a long time, and a lot of wasted water, before it comes out warm/hot.

I have heard about the tankless water systems, but don't know anything about them. Is one enough for the whole house? Do you get one for each faucet? There are only two of un in the house, so our overall water usage is small compared to a larger family. I can imagine we would want to have hot water in the shower and maybe a sink. We usually don't run more than one appliance at a time.

I would like to get hot water to where I want it faster than I currently do, and I would like to save water and energy. Is there a system that can be recommended for my household? Does a regular hot water heater make sense? If there is an alternative, what would that be?

Thanks for all of your help.

Tim

kksmama,

The answer to your vent question is an unqualified "No". Venting of a tankless gas heater is fairly strict. You can go through the wall to the outside and avoid going through the roof, however.

The venting material is Stainless Steel and expensive, you want it to be as short as possible and you can't combine it with other appliances.

It's often easier to locate the heater outside where the weather is mild, and run PEX water lines than it is to do a vent through the roof. Get a plumber involved who knows tankless heaters.

hittlets,

Gas Tankless systems are most economical for whole house situations. The total installed price is much more than a tank heater and wouldn't make sense for individual water outlets.

A whole house system will also increase the time before you get hot water at an outlet by a few seconds.

The first thing you need to do is see if you can insulate the hot water pipes. You might look a recirculating pump. I like the idea of a recirculating system on a motion detector.

A point-of-use heater can also be a help on distant water faucets. For the distant master bath, an electric tankless can be the right answer in some situations.

You really need to evaluate the entire setup, including access to insulate the hot water pipes.

There are many posts on recirculating hot water systems. Do a search and see the entire debate.

Thanks for the info! We get hot water fast now in the kitchen/laundry because they are close to the garage. I'm not sure I'm willing to give that up to go tankless, but I will get a knowledgeable plumber to come and see my setup and make a recommendation. I've learned a lot these last few days and know what I'd do on new construction, but retro-fitting a house on a slab foundation is a different endeavor.

Frankly after our wood floor disaster, I'm not sure it is a great idea to have indoor plumbing at all, lol! Or maybe it is the wood floors that are a problem.....

I don't think we're going to spend the money on a whole house tankless unit, the gas guy came today and said we'd need a lot of vent to get through the attic and a new condensate line. I'll call a local plumber about doing an outside mount one for the master bath, but I am worried about the mess and destruction of install - I'm weary of seeing my house torn apart.

I think I'd like to get a 75 gallon unit but am not finding many choices in propane. The propane company quoted $900, which is hard to pay when Sears sells natural gas units for less than $500. Any suggestions?

FYI- Just installed a Tankless Water Heater along with my AC and Furnances. Gas bill seemed to reduce about $10 a month, but it seems to use a little more water because of the heat-up process. It cost me about $1,800 to purchase and install by the vendor who did my AC and Furnances. Mounted on the garage wall and vented straight out, about 10' from where the water tank was. Vendor just ran the copper lines to the wall which did not take long. 2,300 sq ft house with 2.5 baths, installed a 8.5 gal per minute which was recommended, especially for colder periods in Marietta, GA. Still waiting on the $300 rebate which seems to take forever. No running out of hot water problems with 5 in the house. Did cost more, but I was informed it could last up to 20 years, will wait and see.