Cold tap runs burning hot for 10 minutes
We finished a complete kitchen reno several months ago. The two kitchen sinks both run very hot water from the cold tap for approximately 10 minutes, before the water finally becomes cold. Then, if I wait twenty minutes or so, the cold tap again becomes hot and I have to run it another 10 minutes to get cold. This happens only in the kitchen. The bathrooms are fine--and they are approximately the same distance from the water heater as the kitchen.
We had a recirculator at our hot water heater, which I turned off and unplugged, thinking that was the problem. No change. We also adjusted the hot/cold balance under the sink. But the problem continues. Our gas bill is quite high and I'm sure all this wasted hot water is one reason. I'm worried that our sinks might not have been plumbed correctly during the renovation.
Any ideas what could be causing the problem?