I use an offline chlorinator when I'm away. I recently installes a pentait rainbow #300 off line chlorinator. The fine print suggest installing an "optional" 1/4 inch inflow check valve #R172323. I already have another 1 1/2 inch check valve after at the heater outlet. When I spoke with teh Pentair tech support they basically explained that it is really a "must have" to protect pump and other equipment. Just wanted to let folks know.
I suggested to the rep that if this is the case they should include it.
Anyone have any thoughts?