Jstumbaugh
WKR
Navien has a negative pressure gas valve and doesn’t require a gas line upsizing for most applications depending on piping length. If you can tie in a recirc line I highly recommend it and a unit designed for that. That eliminated the “cold sandwich” and any lag time at the faucet. Definitely use the valving kit to make descaling easy. This should also be done with tank heaters but no one tells you that. White vinegar is a good cleaning agent. Most house natural gas meters and regulators can handle 400k btu. Most lp regulator systems are above that. $.12kwh electric is not normal around her. I’m in upstate ny and we run about $.19kwh