Hot water in the toilet
Help! I have a 17 floor high rise I maintain. Hot water in the toilets showed up on the 14th floor restroom first. Now it is hot on the 17th floor rest room and all cold water valves. The 14th and the 17th floors are not on the same water heater. One water heater per three floors. All shut offs are individual single handle and flush valves. I have seen single handle mixing handle let the water go the wrong way. but I dont have them. I've been doing this job for 23 years and this is the first time this has happen. Can anyone help me please.