Did a job yesterday with radiant floor heat, water. The supply was from its own well and it used a propane water heater for its heat source. Among leaks, there was no temperature control valve to control water temp through the heating tubes, I was told by the installer the water heater was set at 120 degrees and that was fine. Is that an accepted way to control the systems temperature ? I still feel a temperature control valve should be installed, I asked for permits to be obtained.