After a lot of plumbing and drilling holes through my concrete basement my heat exchanger (plumbed to my gas water heater) is running perfectly. Pool reached 84F within a few hours and had to shut the heater off... manually.
My set up is unorthodox and I need a thermostat with a probe to control my 110v circulator feeding my heat exchanger. Ideally I'd find something with one with electronic controls and a web (iOS) interface, but Google isn't responding well to my queries.
Anyone else running something similar?