in that case your water heats up faster than the small amount of extremely cold water from the chiller....thats why work so hard...
use too strong a pump...and the water flows pass the chiller without getting chilled enough.....
so either way abit problem.....i think they recommend about 380 to 400gallon/hr flow through this chiller...meaning about 1400l/hr...
i am using a sicce extrema to move water through it....although it is rated at 2500l/hr...but after overcoming height head loss and hose pressure loss, should be around the chiller's recommended flow rate..