All of Caleffi's storage tanks have multiple ports. Installing a temperature sensor thermowell in one of them is easy.
Our chrome-plated brass NA15029 thermowell has a 1-3/4" insertion length, 1/4" bore, and 3/4" MNPT threads. That thermowell is designed to hold the Caleffi 257206 temperature sensor (compatible with iSolar controllers) and to be installed in a 3/4" FNPT connection. Our 25 gallon ThermoCon tank has a 3/4" port on the side - in the upper half of the tank - and is perfect for a thermowell. Caleffi SolarCon tanks come with one (or two) pre-installed NA15029 thermowell, ready to go for solar applications.
The 50, 80 and 120 gallon ThermoCon tanks all have 2" connections on the sides; to mount a thermowell to one of these ports, use the NA10234 adapter bushing (2" MNPT x 3/4" FNPT). Actually any common thermowell with a 3/4" MNPT process connection can work with the ThermoCon tanks, just be sure the inside bore of the thermowell matches the sensor being used.
Also, best practice is to put some thermal conducting compound (such as Caleffi's R69413) in the bottom of the well to maximimze heat transfer from the water through the thermowell to the sensor.
Check our website for detailed technical information on the ThermoCon tanks. Contact us if you have any questions about this topic or anything else Caleffi! We'll do our best to help.