Heating - Thermostat Not Functioning Properly in Madison, NJ

Customer states new thermostat installed is reading higher than the other thermostat.

Upon diagnosis I asked customer if these thermostat location had always been this way, she stated that there was no AC Thermostat before until Pipeworks installed the system in attic space for cooling then mounted new thermostat directly on that location where it’s at. The old dial radiant thermostat was always there, then 8-10 years ago the AC thermostat was installed. 

Upon diagnosis found that Lennox thermostat is giving off heat causing increased temp on the dial Honeywell digital thermostat thus creating the temp difference.