I recently installed a Honeywell TH5220D1003 thermostat (thanks to the help of this forum) and it is working fine except it shows the inside temperature as 2 degrees warmer than it actually is. In order to maintain 78 degrees actual temperature I have to set the thermostat for 80. I have checked the actual temperature with 3 other thermometers and they all show 78 degrees while the Th5220D1003 shows 80. I was wondering if there is a way to adjust or recalibrate the thermostat where it will reflect the actual temp instead of being 2 degrees off. Any advice?

Contact honeywell on there toll free number that came with the install instructions.

Many thermostats are not accurate for the temp reading but accurate for the control of the unit.

Just in case you lost your instructions

http://customer.honeywell.com/techlit/pdf/69-0000s/69-1783.pdf


Also this is a 2 stage thermostat so make sure the wiring is on the first stage and not the second.
This could cause the stat to be off 2 degrees.