When was the last time you changed the bulbs? We re-lamp our washes every 13 months. You?d be surprise at how much the bulbs degrade in just 13 months. In your case I?d bet you?ve got a bad ballast. If you?ve got the yellowed plastic lens, I?d replace them with glass.
If you do need a ballast, I'd recommend 1000bulbs.com and order the Sola brand. So far they've been every bit as good as the Advance brand from Grainger and are a lot cheaper even with the shipping. They can special order the individual components of the ballast too - chances are you just need the capacitor, which is where the thermal protection is.
FYI, when you put 240V in to a 24V transfer output, you get 2400V out briefly, then smoke.
I just went through this with one of my Hubbels I bought from KR. I've never been able to get them to warranty anything. However, after arguing with them and getting nowhere, I contacted Hubbel directly. Hubbel gives a one year warranty. The ballast has a 2 year warranty, but not by Hubbel. I would suggest you open the fixture, get the number off the ballast and call the mfg directly. Skip Hubbel.
I finally got the ballast maker to send me a new ballast and capacitor, and to my surprise they paid the freight both ways. Now that is great service. I just hate to buy them from Kleenrite as I've had such poor customer service from them, and I have bought a lot of stuff from them.