That will make a huge difference in Summer Mike ,with the bypass valve make sure you have a 1.5 - 2 deg difference between inlet and outlet pipe on heater , if you didn't know that already ,will make heater run more efficiently 👍
Bite the bullet crank it up to 18 now and worry bout the bills later, ask Oaki he knows. 😂😎 Glad it’s up and running mate, here’s to an exciting growing year. 😎👍🏻