Oh yeah; put fresh batteries into the thermostat if they need these.It's a whooole lot easier to do these things when the units are empty than when you get a call in the middle of the night.Gail

First 30 Days - Updated the Lower Unit - Cleaning / Paint / Countertops / Windows / Smart Thermostat (Rehab was around $5K.

Have you looked into adding a zone damper system so two thermostats can control one hvac system?

There is currently one thermostat for the whole building located on the ground floor in apartment 1.I know there's no good way to split the gas utility in such an old house, so I was exploring the idea of installing electric baseboard heaters and simply splitting the electric utility for the tenants to pay for themselves.

HVAC contractor will:- supply and install 80k BTU 92% gas furnace on first floor- supply and install 3 ton coil- supply and install 3 ton condenser- supply and install 5 zone fujitsu mini split system on the 2nd floor with copper lines and slim duct (2-7k indoor, 2-9k indoor, 1-12k indoor units)- supply and install new duct grilles and registers- supply and install new refrigeration piping, exhaust piping, thermostat- supply and install new natural gas piping to accommodate gas load Estimate is $17,700 and I have no idea if this is fair or in the ball park.Any help or direction is much appreciated.

As an added quirk, the downstairs unit contains the thermostat for both units. 

The PM contacted the local HVAC service guy in our area, and after their $75 service fee it was determined that the only issue was that the low battery indicator was showing on the thermostat, so it was changed.

When we were there the thermostat was set to 55.

The house was unoccupied and thermostat set on 75.

They can be daisy chained to run off of one thermostat or can have individual unit-mounted thermostats.