I've been using the same 30-plate chiller since early 2009. I've come up with a simple maintenance and cleaning routine that has been working well for me.
1. First off, I
bag all hops and all other solids that go into the boil kettle (fruit, orange peel, spices, Irish Moss, etc.).
For double security, I also have a medium tight (tube-shaped) doubled-up screen inside the kettle (think of a
Bazooka tube), connected to the exit port. Only very fine dust that has made it through the fine-mesh bags goes through the chilling loop. No more flakes or pulp! A stainless hop basket could offer similar protection.
I have Camlocks (1/2" Type A, male) on all 4 ports, for easy (dis)connecting and cleaning purposes.
2. After a brew session (I often brew two 5-gallon batches back to back) I clean the plate chiller, but it may remain attached till the next day.
This only pertains to the
wort side of course.
First drain the chiller, then backflush, forth and back a few times (4-6x) with tap water, either from the kitchen faucet or a spigot/hose outside, until it's clean. Takes about 1-2 minutes, tops.
Note: I have a barb connected to the (kitchen) faucet or outside hose, which I stick into one of the (wort side) ports, and push it down as tightly as I can, with a silicone Camlock washer in between making a face-spray free connection.
Drain the chiller, by holding it vertically, one end up. Then shake the remaining water out, now by keeping the chiller
upside down, with one end pointing downward. Turn it around and shake out the other side. I let it either air dry or stick on the bottom rack in the oven. If you have an air compressor handy, sure use it!
3. Once every few (5-10) brew sessions, or when I feel the urge or need to clean it more thoroughly, I first recirculate warm (and later, near boiling) Oxiclean or (homemade) PBW through the wort side of the chiller, using the kettle, pump, hoses and all, for an hour or so. About 1-2 gallons worth (4-8 liters). I often add a dash of NaOH (drain cleaner) to it for extra oomph. My hop bags and other brewing things that need to be cleaned swim in the kettle while recirculating. The return line (on the whirlpool connection) goes into one of the hop bags, to catch any solids, hop flakes and such, but I never see any unless there was some sort of a mishap, previously.
All that gets rinsed out thoroughly, of course. You can run sanitizer through it too, but don't store the chiller with acid sanitizer inside (e.g., Starsan), it may attack the brazing which is 99% copper.
4. I've been baking the chiller in the oven at 400-450°F (200-230°C) for a few hours (with a few loaves of bread usually) once in awhile, say once or twice a year.
