Heating, Air Conditioning, Fridge, HVAC/York Natural Gas Furnace


Joseph, I have a York natural gas furnace (P4USD12N08001A) in my home.  I think it is about 20 years old.  This is what it is doing.
1. Burners ignite.
2. 45 - 50 seconds later blower comes on.
3. Burners and blower operate about 1.5 minutes.
4. Burners go out.
5. Blower operates about 30 seconds longer.
6. Blower shuts down.
7. Aprox 1 minute later blower cycles on then off for about 10 seconds.

The final step (step #7) does not seem normal to me.  I do not remember this being part of the heating cycle during previous seasons.  Can you comment on this please?


A lot would depend on what type of fan control you have, if it senses heat exchanger temperature ,then possible the calibration is off due to age.If you have a time delay type fan relay ( comes on even if burners fail to light ) not sure what would cause that.I'm guessing you have the first type, that would not be an unusual situation , as there is still heat in the heat exchanger and the bimetal control type senses the residual heat.I would not be overly concerned either way as long as your heat works OK.  

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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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