Whether the electrical can be on the same circuit depends on
1. load.
2. voltage requirements for the heater vs the gas furnace.

Perhaps an additional circuit could be needed. It all depends on the specifications of the water heater.

Try getting alternative quotes.

that 1,200 is for the unit, what about servicing valves what about the venting what about the whole in the wall.
2,700 is not for installation, that might be for things like gas piping copping piping venting, maybe a descaling filter.................. the eleectric is minimal amps some units have a 110 power cord that you hoook right into a socket.

The electrical demands for the heater are truly minimal. It is 110 volts, minimal wattage and plugs in to an outlet.

As far as the install cost: Look, I'm a fan of tankless but I think installers are being stupid about the cost of installation. Homeowners need to say "no". Installers know that you are getting a tax credit, and they are sucking it up.

The vent is through the wall, that's about $200 in materials and the service valves are $100. So let's say there's $500 in materials including pipe and misc. total. That still leaves $2200 for labor. That's stupid.

Jake what about the 4 and a 1/4 whole you may have to cut out of the wall, what about the sizing of gas line comming in. what about the two hours you spend with the customer explaining how a tankless works. iI start at 1,200 for labor and work up.

WiseHVAC: It's a water heater, not a room addition.

Look- it's very clear to me that installers are jacking up the price because of the novelty, the installer's lack of experience with tankless and the tax break. Once they become more common, the price should come down.

What really galls me is when the installer charges a premium and does a bad job of pre-sales consulting -- like the person who had two installed but didn't have the gas capacity to the home to support them.

The price quotes I got ranged from 2700 - 3900.
Asuming the typical tankless costs ~$1000,
Stainless gas line ~$500
Stainless venting & misc copper piping, shut offs ~ $300
@ $100/ hr, the labor costs for a 8hr day is $800.

Always good to get multiple quotes (itemized).

Assuming DIY, there's ~ $800 to be saved.

Then again, with a "professional" installer, there's always someone to blame.

thats correct so you remember that. so what happens when I try to sell the service valves a descaslling filter a house filter just for general sediment and proper venting. Then they they tell me to vent it in the chimney and don't want servicing valves and don't worry about the gas flow. ThenI say well do it yourself. and then they say no because it has to be installed by a cedrtified guy. well these are the procedures that have to be followed. That is why i get $65.00 an hour.

The biggest problem is that many installers do not account for gas flow/ electric requirements or the hot water needs of the client.

Consequently the client ends up with a barely functional tankless water heater or an inadequate system (eg - good for only 1 shower, but not for 2 showers/ baths + dish washer).

David whats a stainless gas line. Gas line should be done in black pipe. A good job may take 2 days to do depending on cutting the whole in outside wall, running the gas line and water pipes diectly. I don't see many homeowners with a 4 inch whole saw for the hilti gun. ( hammer drill) The electric is minimal but should have a on off SWITCH instead of just a plug, makes for a better job.

Corrugated stainless steel tubing (CSST) is a promising alternative to traditional threaded black-iron gas piping for residential, commercial and industrial applications. Its light weight, flexibility, and need for fewer connections and fittings can make it easier to install than traditional threaded black-iron piping. These benefits can add up to substantial labor savings for installers and cost savings for builders.

http://www.toolbase.org/Technology-Inventory/Plumbing/corrugated-stainless-steel-tubing

David who makes it, whas the company name? how much is it, is the price of the mateial going to be more then the labor to put black pipe in?
Seriously My uncled is a fireman and he hates the flex becuase when your cutting thrue a wall witgh an ax you go right thrue them. That is why I stay awsay from it. ON the other hand viega makes gas fittings in copper.

There are a number of suppliers and manufacturers, for example Omegaflex.

The pricing is less and it is much easier to work with than black pipe.

Most new installs use CSST these days instead of black pipe.

Cutting through a wall with any tool without knowing whether there are electrical, gas or water lines is always dangerous.

We paid $2700 and that included sizing consultation, new gas line and electrical out let plus removal of old tank. I hear they have increased their price now to $3200. We are very happy so far with ours. We can run two showers and the dishwasher at once.

$4000 for something that may not work? Washington D.C? Hmmm???

I'm not even going to go there!

I'm not a pro plumber but here's my two cents regarding quotes. Although there are "pros" out there who do sloppy jobs, I think homeowners need to be fair to the other skilled ones who try to make an honest living. A lot of my friends do the same thing: they nickel and dime the contractors down to what they'd imagine to be a fair DIY price, which is usually very far from reality. The first mistake they make is that they assume all the tools are free. Then they assume the know-how is free. If the DIY price is really that attractive, I think they should DIY. Wait till they go out there and research which pipe threading machine to buy for those few feet of galvanized pipes with turns and couplings and they might begin to see the tip of the iceberg. Again, if the DIY price and technical challenge are appealing, by all means, go DIY.

Now unfortunately, due to the existence of sloppy workers, homeowners have to do some homework to filter them out. I think the point is to converge towards a meaningful quote, but not necessarily a lowest-priced quote.

So, wisehvac, I hear you. :)