Cooling water temp

[GuerillaDistilla]

Quick question about cooling water. I have a milehi reflux with cooling jacket (i know, not the best for reflux) and use an adjustable submersible pump in a 10 gallon res. If I run my 1500w hotplate on full, i have to cool the cooling water frequently to keep it under 100F. On the second highest setting, vapor can't come out of the head until the cooling water is 140F. If I were to use the second highest setting, would the 140F cooling water be enough to maintain a good reflux, or will other vapors carry over? Or should I buy a larger res for the cooling water, in hopes it will take a whole run to heat up. I've tried both of the above ways (except for the larger res) and the distillate is comparable, but the thermometer reads ~0.4F higher this way. Any input would be great.