Amana Gas Dryer not heat enough

[SIZE=3]1. Start the dryer[/SIZE]
[SIZE=3]2. Igniter turns into red and then brighter[/SIZE]
[SIZE=3]3. Blue fire starts, for about 3 minutes, it shuts[/SIZE]
[SIZE=3]4. Even though the igniter lights again, it doesn’t start blue gas fire.[/SIZE]
[SIZE=3]5. Stop machine and start again, steps 2 and 3 repeat again[/SIZE]
[SIZE=3] [/SIZE][SIZE=3]When the machine cools, it starts gas fire again. But the cloth is not hot enough to dry. It eventually dry by air flow.[/SIZE]
We clean the vent and machine dust. If the coil valve is the problem, part number AP3094251 is the correct part?

Thanks

We replaced coil valve and it works.