I had a gas dryer in storage a few years. I guess setting around didn't sit well with it. First I converted it to propane from natural gas. This was relatively simple with a kit from appliancepros.com
After a few weeks of use my wife mentioned the dryer didn't seem to be working as it should. After a bit of investigation we noticed that the timer wasn't always advancing, and the heat cycles weren't consistent. I ordered a new timer and installed it as the applianceparts video directed. The video made the replacement very easy and and best of all, the problem was solved and I saved myself a service fee. Win ... win for me.