Also, this tankless system has a sediment component that allows you to remove sediment from hard water before they build up.
Very few generating stations in the US are combined cycle. Most are conventional steam electric stations whether they use oil, coal or natural gas as the fuel.
Unless I’m missing something in your posts, there are still two unknowns: the principle of the loan and the interest rate. Need to know the interest rate to calculate the principle which would be the cost of the heater plus installation.
The OP said that the interest rate is 10%.
Sorry, I misunderstood your OP. At 10% interest for 10 years a $3,325 loan would cost $43.94 a month. Still a crazy high cost and you’ll never see a profit. It’s a rip off from day one.
Since the OP is looking for opinions, let’s move this to IMHO.
Colibri
General Questions Moderator
Around here, tanks have a long thin Sacrificial Anode. You should have that replaced about every 7 years, because it sacrificially corrodes away, protecting your tank.
Most people (around here) don’t replace the sacrificial anode, which means that after about 15 years the tank leaks, and needs replacement.
You ever try to get one of those out ? I read about that on the internet and tried on my water heater when it was about that old. An air impact wrench at 150 PSI didn’t move it, neither did a 2 ft long breaker bar on the socket wrench or a hammer. Finally just gave up and have the new bar sitting around somewhere. Edit to add, have since replaced the water heater, but it lasted another 5 years after that.
We had a clogged pipe a while back, and had to call a plumber out to fix it. I noticed on his website that he was a dealer for a particular brand of tankless water heater, and since we haven’t replaced our water heater since we bought the house 20 years ago I asked him about it. He told me:
a) due to the way our house was laid out, a tankless heater wouldn’t deliver hot water much faster than our traditional heater
b) given the amount of water we use, it would probably take at least a decade to recoup the extra expense
c) after examining our existing heater, despite it being 20+ years old, there was no reason to replace it at this time.
He gave me a ballpark estimate of $1200 for purchase and installation of a new water heater, including some modifications to the existing plumbing to meet new codes…when it becomes necessary.
A year ago, I moved from a house with a tank, to a house in the same area but with a Rinnai instant (tankless) heater. My combined power/gas bill dropped by about 30%. I love mine.
After all that:
Did you remove the anode from the new heater and wrap the threads with teflon tape? Apply anti-seize compound?
If you do this, wouldn’t you need to somehow ensure an electrical connection between the anode and the rest of the heater? You’re essentially trying to make a battery, and an open circuit would impede that.
(I just checked mine, and there is some white stuff near the threads, but it might just be corrosion of some kind.)
**Never, never, never, never, never, never, never, never do business with someone who comes to your door about water heaters or furnaces. **
Allow me to say it again:
**Never, never, never, never, never, never, never, never do business with someone who comes to your door about water heaters or furnaces. **
There are two kinds of people who sell water heaters door-to-door; scam artists and thieves. There are no other kinds. I don’t care what kind of deal he was offering (and this deal was an outrageous scam; you could buy three water heaters for that) or if he offered a pot of gold with it.
If a person comes to your door talking about water heaters or asking to see your utility bills, order them to leave your property immediately. NEVER give them the time of day.
Having once embarked on selling water softeners (which also needs to be added to RickJay’s list) door to door I can wholeheartedly endorse your opinions!
Out of curiosity:
What IS the “I just need to see your utility bill to save you TONS of money” scam about?
You need very little area for the electrical contact, but good catch.
Anti-seize compounds (generally used on engines, in my experience) are copper compounds, to avoid the problem entirely.
nm - they get the account number and switch your provider to some rip-off supplier.
Presumably, my signature would be required to “lock in” the low-low rate.
So were you a scam artist or a thief? 
A poor college student trying to pick up some extra money in a town blessed with incredibly hard water.
A fellow fraternity brother and I established an agreement with a local plumber (for a fixed fee) to install the softeners for a “complete package” system. We did go door to door but that was our best way of contacting people in the late 60’s. We made a pretty hefty markup but we really didn’t scam anyone.