Have you ever had water so hot that it hurt come out of your shower? It shouldn’t be a common occurrence, especially if you don’t have your water heater turned up too high, but there are some situations in which a malfunction leads to hot water coming out of your cold water pipe, and it could lead to scalding if not fixed.
So what could the reason be? It could be something simple, such as a shut-off valve for your cold water being turned off, leaving nothing but hot water coming to the shower. If the problem is not just limited to your shower, however, you might want to take a look at the main shut-off valve for your cold water.
Another thing to check is the pressure balancing valve for your shower. It controls the balance between hot and cold water and if it is set improperly, you could get way more hot water than cold.