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Heating, Air Conditioning, Fridge, HVAC/Thermostat Resetting, power loss?


Hello,I recently replaced my thermostat with a 'smart' unit that has the feature that it will not call for heat unless 5 minutes has passed. This has uncovered an issue I am having with my furnace. What is happening is that the thermostat is operating properly and calling for heat, then I observe on the t-stat what I describe as a 'reset' or a 'power blip' whereby the thermostat seems to 'reboot' at which point it goes into its 5 minute wait before calling for heat again. The result on a cold day is that the t-stat can't keep up with the heating because the more it resets, the more it waits before calling for heat again. I have replaced the t-stat and the replacement is acting the same way. I replaced it with a 'dumb' t-stat and I can tell that the power blip is still happening but because the t-stat doesn't have the 5 minute override, the furnace starts up within a second or two. I do not know how to troubleshoot this as it is an intermittent (yet recurring) issue. I verified that there is 28VAC between the R and C terminals, and when the t-stat is calling for heat I observed 28VAC between the R and W terminals (this test was requested by Trane product support, the t-stat maker). Thank you for your help.


Trane does not actually make t-stats they just put their name on it along with other manufacture. In regards to the smart stat does'nt the manufacture have a phone number to call or e-mail address to talk to a Tech. Rep. typically the stats I have installed usually have a phone number many are toll free.You should always have 24 Volt ac between R and C terminal at the stat as those terminals are the actual low voltage side of the transformer. You should only have 28 volts ac between R and W only when your not calling for heat, once the heat switch closes from R to W to start your heat you should read zero volts,not 28 volts as you state." when the t-stat is calling for heat I observed 28VAC between the R and W terminals (this test was requested by Trane product support" The three big t-stat manufactures are White Rodgers, Robertshaw, and Honeywell. Suggest you find who actually makes your "dumb " stat and call that manufacture. I am not familiar with the smart stat, there are literally hundreds of models of stats,out there I am not familiar with anywhere near all of them.You can try another expert, there is one who specializes in t-stats and control

Heating, Air Conditioning, Fridge, HVAC

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40+ years diversified experience.An HVAC/Refrigeration Self Employed Contractor since 1986. NATE Certifield. Answer questions pertaining to Residential and Commercial Air Conditioning , Warm Air Heating, Heat Pump systems.Mechanical and Electrical troubleshooting of these systems.Be as detailed as possible when describing problem.Packaged unit or split systems.No appliance questions.


Installation and Troubleshooting, Mechanical and Electrical, in following areas, Refrigeration ( Walk In and Reach In Coolers and Freezers ) Commercial Roof Top and Packaged Heating/Cooling ( Natural Gas,Propane, Electric, and Heat Pumps ) Computer Room Air Conditoning Systems,Commercial Residential Packaged and Split Systems Air Conditoning and Heat Pumps.Warm Air Oil , Natural and Propane Gas Heating systems.

Graduated from Private Technical School in 1975. An HVAC/Refrigeration Contractor . Have Unlimited Heating/Piping and Cooling Contractor License.Limited Sheetmetal Contractors License.NATE Certifield. York Certifield Master Heat Pump Technician 1986. Served 33 years combination Active Duty Air Force , Air Force Reserves and Air National Guard in the HVAC/Refrigeration Shop/Mechanical Shop. Troubleshooting/Installing HVAC/Refrigeration Equiptment Worldwide. Retiring in 2003 as a Senior NCO ,and a Mechanical Superintendent.

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