Okay we went tank-less with our water heater. The story to come, pictures to and a long list of what not to do.
And here is the story.
I researched, researched, and researched some more. Takagi, Japanese, Titanium heat ex-changer, Takagi won this purchase. I am not a high demand household for hot water, 1 shower at a time typically. I opted for the base natural gas indoor model – Takagi T-KJr2-IN-NG 6.6 gallon per minute GPM. I first installed the black pipe gas line using 1/2 inch. The unit worked but kept getting combustion error 99.
(Okay so let me explain- when a tankless water is not running right 99% of the time it is something outside the unit; water supply, gas line, plumbing, venting.. you get the idea. So when it isn’t running right you get what people who have one call a ‘cold water sandwich’. a CWS is when the heater turns off and while you are mid shower you get a pocket of COLD water. 30 seconds maybe while the unit then restarts and continues. You might say I have had that happen before and yup likely in a hotel. Many hotels in AC use tankless water heaters.)
I reran the black pipe for the gas line at 3/4 inch to the unit. I am still getting cold water sandwiches CWS. I verified venting Cat III stainless. Double checked plumbing. I am still getting cold water sandwiches. Granted not as often and the other day i had one cold water sandwich then a 15 minuted uninterrupted same temperature hot water and the was FANTASTIC!
I am still working out kinks, I thing we have weak water pressure when everyone uses it at once and our neighborhood uses ground water. My point I think I need a booster pump? Another 1000 bucks :/ for a good one maybe $750.00. it would provide consistent water pressure no matter how many faucets are open. That sounds like it would fix these cold water sandwiches. I am testing the pressure tomorrow with new gauge.