Does a tankless water heater need a check valve?
Control valve for water heater without tank. It is probably a co-regulation of the water supply to stop any possibility of return to the network causing contamination. If you have a filling tube tank, it is usually above the water level only for return of flow, so you do not need a valve in this case.
FREE Virtual Home Repair
We'll diagnose your issue over call or video and virtually walk you through the repair — all for free if you're a new customer! .