Hi Wendy,It might be wise to ask for a written list of items.If they pull the hot water heater, or the thermostat, or the furnace, or the outside A/C Coils, or the exterior door locks you might want to (re-negotiate) with them about those items--or maybe not depending on the age re service life left in them.That will also let you build a punch list of buy items (re supply delivery shortages due to Covid) and maybe pre-buy them.Just my 2 cents.

In Dec the tankless coil failed on the boiler, so I had an indirect hot water heater installed immediately.

The technician came out yesterday and determined that there was a bad 4-ton evaporator coil and a few other parts.I received a notice from AHS saying that only some parts would be covered.

Hot water is also provided by the boiler (via a tankless coil inside boiler). 

@Peter Morgan Residential HVAC systems have two components (hence "split"): an indoor unit (evaporator coil) and an outdoor unit (condenser coil).

I had a service call last year for AC not working and it turned out it was a plugged HVAC filter that lead to the coil freezing.

Like was already asked, is there a scuttle large enough to get a furnace and evaporator coil through?

I have been told that my air conditioner "The system unit needs to have Freon up to 8lbs to 9lbs and replace Coil Condenser.

for Air Conditioning parts like an evaporator coil, or a condenser? 

We actually remove the a-coil and water tank as well in certain areas of Memphis.