Dryer doesn't heat properly

Dryer Repair
,
1

My dryer produces heat but not nearly enough. Like, 4hr for a load of towels.

I have replaced the heating element assy, the thermal limit fuse and safety thermostat. Also, the heater thermostat (in the btm pan under the blower) and its control. I have studied your xlnt repair forum and checked voltage, continuity and resistance everywhere as advised. I can’t find anything wrong electrically.
The next step was to verify proper air flow. My exhaust duct travels vertically up an in-wall shaft, through the attic and out a louvered roof vent. Total length is not more than 10ft. I have checked outflow at the vent and it seems okay though I’m uncertain of what the correct cfm would be.

Please advise. I’m out several hundred $$ so far and don’t relish the thought of having to buy a new unit after all.
Thank you.

2

There is a simple test to determine if the problem is within the dryer or with the exhaust (venting). Take off the vent from the back of the dryer and run it with normal load. Improvement in drying time indicates venting problem.You also would need to clean the blower and lint filter compartments. To clean the house vent use a professional duct cleaning company.