Suddenly only hot water from both cold and hot valves

[1bobbylane]

This afternoon, my wife alerted me that in the kids bathroom, which has two sinks, that hot water was coming out when the cold water was on. I had sort of noticed this happening in the kitchen the other day, but didn't pay much attention. I checked it out, and sure enough, when you turn it to cold in both sinks, hot water comes out. Same temp as the hot water side. I felt under the sink while it was running, and the cold side supply line is hot. Any idea what could cause this. The other side of the house where the master bath and 1/2 bath are seem fine. Thanks for any advice before I call someone out.

 

[johnjh2o]

If your tub or shower faucet is single lever you may have a failed cartridge. What make faucets do you have? One other cause could be a bad check valve on a hot water recirculating system.

 

[1bobbylane]

Thanks John! The house has two recirculating pumps. I turned them both off and cold water has returned to the cold faucets. Thanks for the suggestion. I'll figure root cause out later, but at least wife can rest assured the kids can stop burning their hands.

 

[johnjh2o]

If your recirculating system is using a dedicated recirculating line then the check valve on that line needs replacing. If your system is the type that uses the cold water line then the crossover fitting has failed.