When I turn on the hot water I start to hear cracking or sort of expansion sounds in a couple of parts of the house. When The hot water is turned off
I still hear some noise. Is it the pipes or could it be the tankless water heater needing to be cleaned?
Probably just the pipes expanding and where they pass through joists or clamps they are tight so the pipes reposition themselves in small increments.
Then the pipes cool down and the process reverses.
The average homeowner who lost his house in the Oklahoma tornadoes should move for good and not rebuild. Too much complexity watchdogging the contractor. Too much a chance to be defrauded.