from experience it doesn't take much time to blow a heater. Day one of my reefing journey, thought I was connecting the lighting just to see how things worked, smelt somethign funny and within 30 seconds... POP!!
Long story short I was prolly the first person to vacuum out the back of an aquapod and luckily the LFS was still open to grab another.
P.S. though not a veteran persay; I have been wounded in this hobby so that should count for something.