THHN Wire for Hot Tubs Dec 28, 2012 Many of our customers purchase 6 AWG THHN Wire for Hot Tubs. We would like to give a big shout out to Rob in Oklahoma for sending in these pictures of him at work installing his hot tub. THHN/THWN Share: Posted in Customer Projects NEXT →Welding Cable & Wind Turbines Related Posts What Size Wire For 50 Amp Service From Main Panel? What is the Difference Between THHN Vs. THWN Wire What Size Wire for 100 Amp Sub-Panel?