Greetings. I have an outdoor hot tub. Like the water to be very very hot, most commercial models won't go above 104 degrees. The vendor I bought my tub from spliced a 300 ohm resistor into the thermostat heat sensor line which allows my tub to get up to 107-108. We just had to replace the thermostat, going to splice in the resistor, asked the vendor about doing something different so the water can get a little hotter - either two of same type of resistor or one rater higher (not sure if I am using the correct terminology), vendor said can only use 1 of them max but could not explain why. Can anyone assist or perhaps suggest a way for me to get hotter water?

Please no admonitions about the dire safety hazard posed by hot water. We have no pregnant ladies or small children. I am a big fan of some of the hot springs out west, some of which get as hot as 116-117 degrees. I like hot water!

Thank you.

Here is the problem. From what your saying and also from what I have looked up. I determined that your hot tub was built to what they call " #UL 1563 (Electric Spas, Equipment Assemblies, and Associated Equipment)" specifications.

We can not give you advice to go beyond those specifications and I find it amazing that any professional would exceed those specifications for you.

What your asking for can not be given out by this site.

Please consider this when making any temprature changes.
Table 1 - Water Temperature Effects on Adult Skin

(Source: Report prepared by Dr. Moritz and Dr. Henriquez at Harvard Medical School in the 1949s)



Temp. F 1 Deg Burn 2 Deg Burn

111 270 Min's 300 Min's

113 120 Min's 180 Min's

116 20 Min's 45 Min's

118 15 Min's 20 Min's

120 8 Min's 10 Min's

124 2 Min's 4.2 Min's

131 17 Sec's 30 Sec's

140 3 Sec 5 Sec's

151 Instant 2 Sec's

158 Instant 1 Second

160 Instant Instant