Is FC 9? that's not low for CYA < 30. No CC is good.

We don't advise using Boost on a SWCG - The button should be labeled "Kill my salt cell!". I'd use bleach to raise the FC and to shock the pool - 1 gallon of 8.25% bleach will raise your pools FC by 9ppm.

I doubt you'll have much luck raising the pool temp adding hot water from the house. A 50 gallon water heater half full of 130 degree water won't make a dent in 9,400 gallons. I suppose if you spray it on the swimmers?