My hot tub runs on 220. When I turn on both pumps the red wire get hot and melts the cap. The gfi does not trip. Could it be a bad ground or is it miswired?

I see you are covering your bases by posting this on electric and Spas. You are already getting some great questions on electric, try to answer him. Your pool is more likely 240.

You didn't say what brand hot tub you have, but some things to check:
1. Check for any loos wiring or screws holding the wiring in place.
2. As the heater gets older it draws higher amps thus causing more heat. How old is the spa heater?
3. When all pumps and equipment are on you could be execeeding or approaching the AMP raring of the breaker and if any of your equipment is old (Pumps, heater, blower, etc.) they could be causing the system to work harder, thus causing a build up of heat.
4. Try first turning the heat down as low as it will go and then run both pumps to see is line heats up. One of your components could be causing the problem.

God Luck

You didn't say what brand hot tub you have, but some things to check:
1. Check for any loos wiring or screws holding the wiring in place.
2. As the heater gets older it draws higher amps thus causing more heat. How old is the spa heater?
3. When all pumps and equipment are on you could be execeeding or approaching the AMP raring of the breaker and if any of your equipment is old (Pumps, heater, blower, etc.) they could be causing the system to work harder, thus causing a build up of heat.
4. Try first turning the heat down as low as it will go and then run both pumps to see is line heats up. One of your components could be causing the problem.

God Luck

It's a cal spa and its about 15 years old. They only thing I have replaced is one of the pumps. Although it has tripped the breaker if I have both on for long periods. I just want to make sure there is no way someone could get electricuted while in the tub

All tubs should be wired with some type of GFCI or disconnect 5Ft. From the tub or the GFCI might be located in in the main panel box. The purpose of the GFCI is to protect against current leakage to the water, however if your wire are getting hot enough to melt that is evidence that something else is going on with one of the electrical appliance in the tub or one of your connections are loose.

If you have never replaced the heater take a look around the electrical connection points for the heater on the heater barrel and if you see evidence of rust this means you have some water leakage no matter how slight and this could cause the GFCI to trip or it could even cause the condition you described earlier.

With the age of the spa the equipment is laboring harder.