Water back flow

[Mdbordelon318]

When someone is in one of my self serve bays. And is using the high pressure wand and stops spraying. Sometimes the water backs up into my water holding tank and starts going out the overfill / overflow line. In 6 ss bays it looks to happen more when they using bay 2. Any ideas from any of y’all to the cause ? Check valve ? Soltoid

 

[Greg Pack]

if your system has a hot water tank and a pressurized cold water feed, you may have a bad check valve. The valve would be located between the water tank and the pump inlet. On Coleman pump stands it is a well type check valve and is located under the tank. When these valves go bad pressurized water from the cold rinse makes it way back to the tank,overflowing it. You can test it by turning on the rinse in bay two and then reach down in the hot water tank. If you feel cold water running out the bay two port then it's a bad check valve