Heating, Air Conditioning, Fridge, HVAC/Thermostat Variance


    I recently switched my 2 story home in the mountains of S. California to a 2 zone system - 1 thermostat upstairs and 1 thermostat downstairs. Both thermostats have a 1 degree variance, so the natural gas furnace/ac come on more frequently to maintain the set temp to the actual selected temperature. My previous thermostats had a 2 degree variance. For a set temp of 70, it would kick on at 69 and turn off at 71, which resulted in less off/on for the furnace/ac.
    Given the 1 degree variance for my new thermostats, coupled with 2 different zones starting up and turning off, it seems as if my furnace/ac are coming on/off quite a bit. It keeps both zones very comfortable. My question is this - Will the added startups/turnoffs indicated in my system wear out my furnace (and ac in summer) much quicker, or are furnaces designed for this kind of off/on activity. If the answer is yes, what part of the gas furnace would need to be replaced more frequently and what is the approximate cost of such a repair ? If it's a relatively inexpensive repair that I would be incurring for the added temperature comfort of my home, I could live with that.
     Thank you,
         William -

I don't have any scientific data on how long it takes to wear out a furnace under different conditions if there is any such thing?
I don't know what type thermostats your using but most all have a set able cycle gismo for longer or shorter cycles accessible by removing the front cover.

Heating, Air Conditioning, Fridge, HVAC

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Jim Barnhart


Fifty + years conditioning the air.


Answer questions about , residential and commercial. Answer questions about sheet metal fabrication. Fifty years plus experience. No answers for oil equipment, No answers for kitchen appliances, No answers for laundry appliances, I don't specialize in one particular area of the HVAC area, I'm more of a General Practitioner, Limited in refrigeration/

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