Our 2015 OC 45 has been 3 years in Kemah TX and is now in Stuart FL. The AC cooling circuit has been an issue since the first season. As well as keeping filter clean I regularly flush the system using the Sea Flush Filter kit and snorkel. It’s $100 at Amazon, seems expensive for a couple of plastic funnels and a couple of bungee cords but it fits all the suction strainers perfectly. I get a 5 gallon bucket with a 10-20% Muratic acid fresh water blend, stick snorkel in bucket, switch system on and pump the 5 gallons through the system. Refill with fresh water and a bicarbonate soda mix to neutralize acid. Full flow is restored. Do it every 6 months or as required.