There is a pump that circulates water from the tub through the coils of the exchanger. 

People will be made poorer (inflation is a worldwide problem), houses will rise in prices (along with metals and commodities.

I wanted a metal roof, doormers, solid stone cabinets, new porch, but none of that was needed.

Yourcomparing metal buildings to metal buildings, right?

This can be precious metals, specifically gold, you could hold on to more cash now if you think the market will move and there will be buying opportunities available.  

One chomp death.Rats are mean and fierce fighters (and DO NOT belong in your home).They carry diseases:https://www.orkin.com/pests/rodents/rats/diseases-that-are-spread-or-carried-by-ratsLet the rodent experts do their job and follow their directions.For instance if they say use covered metal cans do so, and etc...If the rats are stuck outdoors due to being sealed out, they will just be out there in the wild like squirrels.Just my 2 cents.

We also discovered that the amount of items moved into common areas on the property (garage, backyard, basement and entry ways) had grown to the point where access to the electrical panel was obstructed, flammable items (i.e. open coil heater and mattress) were in the vicinity of the furnace and water heater and a garage that was barely standing was packed.

I also say that if the air handler coil starts getting dirty I will know they have been negligent and that they may be paying for a coil cleaning.  

We do like them, they are responsive and met all the screening requirements.

We also had one where the evap coil was literally coated in nicotine so was not performing effectively.