Rinnai installation help

I am purchasing a
RL75i (REU-VC2528FFUD-US) and need to know what all do I need to purchase to make sure the plumber has everything he needs to install correctly? My licensed plumber (friend) is taking care of the installation on the side for me as a favor to help me save money. BUT I have no idea of all the pieces I'm supposed to buying for him... ie venting material, or anything that isn't mentioned when I buy the system. Can anyone offer me some help in knowing what to purchase???

without looking not really. gonna need some adapters, some 90's a valve or 2

some screws, solider or glue? i dont know

ask your plumber, to give you a list

He's installing it. Ask him what he wants and get them for him.

You will need the vent kit. But i would save the money and go 50 gallon power vent. I have had nothing but trouble with tankless and no money savings unless you get the rebate up front. If you don't flush every year you will void the warranty, just the cost for flushing wipes out any savings.

Is the warranty specific to Rinnai?

(My Navien is 5 years old and has never been flushed, but is still under warranty)

It depends on the manufacturer's warranty policy, and on your water.

Example for a Noritz I installed a couple of months ago, no annual flushing required if the hardness of the water is 3 grains per gallon or less, 3-10 GPG requires annual flushing, above that requires treatment to remove the hardness.

I know the year i worked service for my buddies shop some of the installs he did had trouble with warranty issues because the customer did not flush on yearly basis. The year i was there he went through Navian, Noritz and Rinnai. I am not sure which one was the issue. My parents have one and the last issue was 10 days waiting for the warranty part to come in. If your not running a Jacuzzi tub i see no benefit.

We also had issues with not enough gas volume and had to do a meter upgrade at i believe 700.00 per. I have seen several starved of gas because the gas volume was not sufficient for the tank-less and existing gas appliances.

I had a Navies rep overview the install (nice that the factory is local) and in the 5 years it has been installed, I've saved boatloads of money on both my water and natural gas usage...

I am glad it worked for someone. My father is very frugal and said if there was any savings it has been minimal. I wonder how the gas savings work when your tankless is a much larger btu than 40 gallon burner. Tank less around 190,000 and 40 gallon around 40,000.

I have read several articles on the comparison and in most cases real world applications have seen a savings of around a hundred a year. Throw in the flushing out charge and its a wash.

The one at mom and dads house has left them without hot water a total of 26 times in 6 years. I will go power vent and the up front savings