my gfci breaker kept tripping found out it was a bad 30 amp breaker so i replaced that. it worked for 2 days and now it keeps tripping again and i cant figure out why...any info on what to try would be awsome. when i replaced the 30 amp i was getting the proper voltage out of the heater so i cant think of what the problem could be

What's the serial number?

The 30 amp breaker either powers the heater, or the rest of the equipment, but not both. If it's isolated to the heater, either a bad electrical run, the heater is bad, or you replaced a bad breaker with...another bad breaker.