My dryer does not heat up when it is hot outside?

Whirlpool dryer. No heat. There is a buzzing sound at time when gas should ignite but no flame. Element glows?

• Dryer is 3 years old. Not used for the past 2. Barrel spins, all controls work, there is a 'buzzing' sound which I think is coming from the gas 'regulator', which comes on/ starts at the point in time when the gas should ignite. I t seems that the gas is not getting through to the igniter. I opened the front cover and looked inside. all seems clean. Vent duct is clear.

• Answer:

  The sequence of operation is: Igniter glows when dryer is calling for heat. After ignitor glows "red hot", the flame sensor opens from the heat the ignitor producers. After the flame sensor opens, the ignitor goes out, & the secondary coil on the gas valve opens, letting gas pass through & light. If the ignitor comes on, but doesn't go out, the sensor is bad. If the ignitor goes out, but gas doesn't come on, the gas valve coils are bad.