Instant hot water everywhere BUT the kitchen

How do I diagnose this? We stopped getting instant hw only to the kitchen - everywhere else in the house is fine. The water does get hot eventually. The recirculating pump is installed next to the hw heater. The entire plumbing system is less than 5 years old (total remodel). What is happening here?

Peter
(rank amateur but . . . willing to learn)

hw

Unless the kitchen is part of the circulation loop, then it will still have to evacuate the cooled water from the pipe before you will get hot water. If the kitchen is part of the loop, but is the last item and the check valve has failed, cold water can back feed to the kitchen and give cold water until the hot water supply can overcome it. What you describe cannot happen if the kitchen is part of the loop and everything is working properly.

Thanks for the help. Until recently, the kitchen got hot water seconds after the faucet was turned on therefore, it must be part of the loop and the problem is a failed check valve. Am I correct?

If so, what is the life expectancy of a check valve. This system is less than 5 years old . . .

water

It COULD be a failed check valve but you have to test it to see for sure. Check valves can fail in a year or so, depending on the quality of water and the valve.