OP the core 4 while sounding cool is very very risky ..

But there is nothing like the eyes of someone that has installed a water heater, replaced a breaker box or laid a floor to really get to the bottom of the true issue on a home fast. 

Here in TX the soil is mostly clay, and it shrinks and expands with humidity level (thus the need to "water the foundations" as a measure to avoid foundation cracking), so foundation problems are a common occurrence.

What’s the water pressure?  

Curious if anyone has tried the smaller 20 gallon water heaters? 

and two of others (furnaces, water heaters, appliances, etc.?) 

Electric stove, dryers, water heaters, and high-efficiency Mitsubishi heat pumps.

That is a cool map!  

It has separate gas, electric, two hot water heaters, etc. 

It took some calming him down and producing the disclosures he signed and convincing him not to contact his lender, to cool the issue.