TUBE problems

Hey guys,
I have a 3 year old Hot Rod Deluxe. the other day i was playing, and the volume dropped out and there were some severe popping and hissing sounds going on, i looked at one of the power tubes and it was bright red. i called the repair shop and they told me to try reseating the tubes, so after they cooled off i took them out and reseated them, made sure the contacts were clean. everything seems to be ok now, but i'm still concerned. the lettering on the tube that was glowing is now all faded, almost exactly what you'd think would happen if it was super super heated up. these are the stock 6l6b GT's that came with the amp, they should last longer than three years right? this amp never moves, sees MAYBE an hour or two per week of low volume playing, so i'm assuming the tubes should last a lot longer than this.
not sure if its coincidental or if it matters, but at the time my wife was using the vaccum cleaner in the next room, could have been on the same circuit i'm not sure. could that have anything to do with it? i have often heard hissing and stuff, but it comes and goes, i guess i attributed it to the likely dirty power in my old ass house. anything you guys could recoment for a budget power conditioner? is that necessary? its all on a surge protector right now.
thanks

3 years is actually a long time for power tubes to last. They can last longer, but usually ~2 years is the average, for a non gigging amp. The vaccum cleaner being ran could definitely played a roll in how the amp was acting. I've heard all sorts of pops, clicks, and hisses and such when certain appliances come on/off, etc... I would say that it's about time for a tube change. Dieing power tubes can cause all sorts of funky stuff to go on with an amp. They can blow fuses, cause a loss of volume, cause unwanted noises, etc...

My 1977 Ampeg VT-40 is still running the original Magnavox (re-labeled Sylvania) 7027A power tubes. That's nearly 30 years.

That glowing-hot scene is called red-plating. It happens when too much current flows through a tube, causing the plate to heat up so much that it glows. That will seriously shorten the useful lifespan of a tube. It was probably caused by a failure in the bias circuit that allowed the tube to run flat-out. Poor contact with the socket may cause this. But another likely suspect is a cracked resistor or a bad solder joint in the bias circuit. This condition could re-occur, and take out your tube(s).

You now have a power section with one fried tube in it, so you should replace all of them. Get a tech to thoroughly check out your amp, replace the power tubes, and set the bias.