Review on 🚿 Plumbing Code Compliant Shower Shutoff Valve: No Pressure Loss, Solid Metal Construction, Push-Button Trickle Control, Chrome Finish by Trey Crosland

My shower valve is old and doesn't mix well. This check valve lets some water through, which isn't a big problem. The main problem is that when you use the slider to get the flow back to full, the water is no longer warm. It's all cold water for a while. My guess is that since there is little flow through this check valve, the cold water is flowing at a slightly higher pressure as it doesn't have to flow through the water heater. Because cold water is at higher pressure, it is more likely to flow through the valves than hot water, which is at lower pressure. I've also tried a shut off valve that doesn't allow water to flow and the temperature is fine.