I did manage to find a way to control the temperature remotely. There are thermostats available that use remote temperature sensors instead of having the sensor in the unit. While browsing Ebay I found one from the X10 home automation system that uses a remote sensor. I'm not sure what other companies make thermostats that use remote sensors.

All I had to do was drill a hole in one of the pipes between the pump and heater and push the sensor in and clamp it with a hose clamp. That wire connected to the thermostat inside and with the heater in bypass mode the thermostat temperature can be set and sends an on signal to the heater which turns it on. When the set temperature is reached the signal is stopped and the heater turns off.

This is so much more convenient than running around and through gates just to check the temp. Hopefully this will help others.