Replaced a 20+ year old natural gas 75 gallon water heater recently with an equivalent model. The plumber said an expansion tank was required per code. Two things I’m noticing now with the new set up:
1) Low hot water pressure: I used to turn hot and cold on full to fill a bathtub. Now, if I turn them both on full only cold water comes out. I have to turn the cold to half and hot to full to get a decent flow.
2) Two people took baths at the same time (one a whirlpool) and we ran out of hot water for the first time ever.
Is this because newer equipment (same specs on paper) isn’t as good as old equipment? Does the expansion tank explain any of this?