Question on t-stat temp readings

[buickgn]

Using a Honeywell Vision 8500 on a oil fired forced air furnace. Temp reading on the t-stat seems to take a long time to react to temp changes. Verified this with an accurate thermometer resting on top of the t-stat. At times the reading on the temporary thermometer will read almost 5 degrees higher than the t-stat temp. When the system is off for a while the temps of the t-stat and the temporary thermometer are exactly the same!

Does the temp reading have anything to do with the operation of the furnace or is it just a reading??

[cem-bsee]

gauge | indicator on t-stat has nothing to do with equip control -- on old mechanicals, anyway --

are you comfortable?

[bdawg]

Is that the RTH8500? If it is, then it's a touch-screen digital TS.

I have a VP8321, and found that it cheats by manipulating the Inside Temperature display. It works (governs the furnace) as expected, so it knows the actual temperature, but fools the hapless homeowner by these slowdowns and by abruptly reaching the set-point if the IT is within 1-2 F of it.

It's not unlike the analog face of the digital fuel gages in cars; It takes a lot longer to go from FULL to HALF-TANK than from there to EMPTY. The aim is to make the consumer believe that it has such a great fuel economy...