Sanitization? Do I just run the pump the last 15 min of the boil, and pump water from the valve back up through chiller?
[COLOR="Sienna"]I give it a good scrubbing prior to brewing - clean to the eye. Put the entire chiller system in your boil the last 15m. I recirculate as well to sterilize my brew hoses.[/COLOR
Can you pump boiling water through the pump?
As long as the pump is rated for high temps. If you are using the standard March Pump then - yes.
Should I install a valve to control the flow of the pump?
Yes. You will likely have it fully open for whirlpool, but you will need the control of your pump for other applications (like sparging)
I guess, what I'm asking for is, what's the best way to use this whirpool chiller? from start to finish.
I actually use two pumps for whirlpool. I live in Texas and brew 10g batches - so chilling is an issue. During chill, I recirculate wort through the whirlpool. I also pump ice water through the chiller. Many people use a submersible pond pump for to do this, if you don't want to invest in an additional March Pump. The important part is to keep your kettle covered during the chill process - especially if you brew outside. Once you get the wort down to temp, quickly pull the chiller shut every thing off, cover the pot and WALK AWAY. Let the wort settle for about 15mins. Most of the cold break and hops will fall into a big pile of trub and you will send clean wort to your fermenter. I just use my whirlpool pump and pump straight into the fermenter.