Timer Knob Will Not Advance
Open Dryer Console
This complaint only applies to older designs with classic timers with rotating knobs. It does not apply to computer controlled dryers. This complaint is easy to diagnose by asking one question. "Does the timer advance fine on timed dry, but not on automatic?"
There are two possible answers:
1. "It will not advance on either timed dry or automatic dry." Careful here. Some customers will not carefully think through the question and give a quick answer. If they never use the timed dry option, how do they know? If the timer fails to move on the timed cycle (kind of unusual) the timer itself is obviously bad. It will not move on any cycle. The timer motor has failed; order one and replace it.
2. "It works fine on timed dry, but not on automatic." Ah Ha. This is by far the more common answer and it means that the vent is clogged.
See dryer theory thermostat logic in my Dryer Manual for an understanding of this convoluted logic. Get the customer to call a vent cleaning service or pull down the entire duct system and clean or replace it. Customer always say, "I always clean my lint trap." They are seldom aware of the 5-40' run the 4" duct makes before getting to the outside flapper. This is a chronic problem in new houses with upstairs laundry rooms that must feed the vent all across the house to exit. To prove this to a doubting customer, get them to run a load with the vent disconnected and see what happens.
Vent Temporarily Disconnected
I personally find all but the shortest duct line a real pain to fool with and gave up years ago. It requires ladders, a vacuum cleaner, a lot of time, plus you will get filthy. A duct that disappears into a wall or ceiling is beyond your capabilities anyhow. It's up to you, but you can make easier money elsewhere. Get them to call the Dryer Wizard.
