Anyone have an electric whole home tank-less water heater?

I have a weekend home and traditional water heater rusted out. No worries I have American Home Shield protection that covers the heater. AHS will cover the heater replacement but the issue is there is $750 out of pocket charge for New Attic Decking because the new heater is taller and will not go in the same spot in attic. Removal and installation of the new heater is requiring an installation of a hand crank winch system and installation of stairs for attic access blah blah blah.

I am thinking a tank-less heater gets me away from the $750 in other charges as I will just leave the old heater in the attic. Waiting on a call back from AHS but preliminarily they believe they will allow me to pay the difference from traditional heater to tank-less-so a few questions:

Is the electric tank-less heater an energy hog?

I assume most run on 220? We do not have gas at this house. 100% electric.

How much more expensive on avg is a tank-less than a traditional?

Any energy savings realized since we are not there much? The demand for water is mostly in the summer for showers at night coming off the lake. We spend a few nights there in the spring and fall but not too much. Mostly a summer place. I understand the heaters work on temperature rise and gpm, so inlet temperature has influence over how efficient they can be.

Any real world experience or comments are helpful.

Sounds like bs to me.
What gallon size is it?
I've changed more than one attic heater out that didn't have a staircase. It's a two person job getting it out and new in but never seen a winch required.
Can you get the dimensions of the existing heater?
All the electric tankless I have seen are not very good. Most require quite a bit more amperage to operate than a standard 30 amp electric water heater.

^^^^^
THIS

Why is decking $750? At $30 a sheet, how many do you need?

The $750 represents

Decking
New up to code water shut off valve
Installation of winch
Framing of opening and stair install.

I am sure that is a hose job.

I believe with those BS costs - it could open up possibilty of tankless?

Sorry.. I missed that. It is not out of line.

Ask for them to pay you the repair cost and arrange your own contractor.

I have three tankless electric water heaters. No way I'd ever go back to tank. The power supply is what you need to check out. Mine are not whole house. They serve three independent bathrooms and one also has the kitchen on it. One also has the laundry room on it. They are all 12-14kw heaters. The require two double pole 40A circuits on 8ga wire. My home was destined for this setup and they so go out. So it's nice to have backups. It's also nice to have a head cold and stand in the shower for 60 minutes without running out of hot water. Units like mine are around 500 give or take 100 depending on brand and size.

Wattage and electrical requirements vary. One of mine has a single 50A circuit so read the manuals before buying and make sure you can accommodate the one you want. I would stay away from bosch.

I'm happy to answer any questions if I missed the mark.

I'll disagree with dropping the home owners warranty, but only if you are will to fight with them. Over the 6 years I have had my homeowners warrant my I have gotten approximately 6k out it while putting only 3.6k into it. We have gotten:

New Hot Water Heater - Same issue on added non covered items, that didn't make sense - Cashed Out $550

Replaced outside A/C unit - material cost alone according to my research was $1,200

Replaced refrigerator - 2k - cash out because I didn't like the replacement

New parts on attic hvac - $800

Plus a bunch of ticky tacky things I didn't want to fix myself

But you have to escalate to a "supervisor" almost every major issue and ***** at them when they send subpar contractors. It's a lot of hold time on the phone, but I drive between Houston, Austin and Dallas a lot so I use the car time to wait in hold.

I have a Takagi tankless heater (gas, with electric ignition) in my house, and I put it in when I built in 2007, so it is in its 10th flawless year of operation with zero issues.

My Takagi is serves the entire house, which is a 4/3.5 plus garage apt, and we have 7 in our family.

I bought the smallest commercial size instead of the resi models, and I'm glad I did. I did the math at the time and it was about a 6 year payback period versus the tank, but not including the fact that I no longer needed to worry about tanks leaking, and of course that included tons of assumptions about usage, etc. The prices have come down since then, too.

So I have a 10 year, zero-problem track record with excellent results. I'll never go back to tanks.

I have a tankless electric whole house water heater on a weekend cabin. The water heater serves two sinks and the shower. I had to have three separate 8 gauge wires pulled to add the water heater and have 3 separate 40 amp breakers to make the water heater work. I have had it for 4+ years and have had no issues and for a weekend cabin I like the fact of not heating water all during the month when it is not being used except a couple of times during the month. I think my unit was around $450 or so. The issue with electric is the wiring.

Thanks for all the replys. Yes the wiring seems to be the major cost for tankless.

I have opted for cash out $627. Hiring a different plumber and coming out of pocket $250ish.