I live in a suburb about 30 miles from Chicago. We get our water through a pipeline from Lake Michigan. In the dead of winter, my current conventional gas 40 gallon water heater can only give me about a 10 minute shower before starting to get cold.
I need to replace that heater and am considering tankless. How can I determine the capacity I need? I live alone and very rarely use any two hot water consumers (i.e. shower and dishwasher) at the same time. I don't have radiant floor heating, so that is not a concern.
Also, if I need a high capacity to overcome that cold incoming water in January, will I need a bigger gas pipe? I *think* I have 3/4", maybe 1", coming into the house, but after it gets split and reduced I'm pretty sure it's 1/2" at the water heater.
Finally, the current one sits right next to a brick chimney. Can a tankless be mounted on the chimney to minimize rerouting the plumbing all over the place? (This question is NOT asking about using the chimney for venting the new tankless.)
Thanks for any advice,