re: Another HVAC Question

quote:

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Change the filter, if that does not help look for a crushed duct/ducts on either discharge or return or possibly some connection came apart on return side.

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I ran it without filter to check that and it did the same thing before I changed the filter.

Also, from return to heater is not flexible duct work, it is a box like a plenum. All of the duct work from the plenum to the vents is all okay, none crushed/bent.