I had the thermostat on my hot water heater replaced yesterday because it was acting up-water was either super hot or just luke warm. Invoice reads " replace gas valve/thermostat, replace cold side waterflex developed crack, drain and flush water heater" . My hot water heater is gas heated with a recirculator and 3 years old. I am now not able to get hot water to my kitchen sink for literally 3-4 minutes, I have timed it several times. Also, it does not seem to get as hot as other spickets in the house now. It is a single handled faucet. All other spickets in house get hot water within 3-6 second, I have timed this as well. I did not have this problem prior to the service/repair yesterday. I called back the HVAC guy that replaced the thermostat this morning and he can find no reason for this new development. This did NOT happen prior however. I know this for a fact--My dad was even upset with me because he said the hot water was immediately hot at the kitchen sink and was afraid I would burn a kid. Dad thought I had a small on-demand unit under my sink, in fact (which I do not obviously). Any idea? I have a plumber coming now to check it out. I am baffled as to why this didn't happen until yesterday. Any idea? Please help if you can! I cannot stand to run GALLONS of water down the drain waiting for hot water!!

It sounds like when he flushed and drained the water heater that he disturbed some minerals built up on the pipe walls and now the crud's clogging your recirculating line.
Have your plumber check the pump, line and flow rate. Let me know, Tom

What does bump mean?

what does bump mean?
It means I read your PM's and went back and bumped up your original post so it could be answered. Regards, Tom

That sounds totally reasonable because the kitchen sink is on it's own recirculating line according to the HVAC guy. I spoke with the plumber and he is coming out tomorrow but he thinks I am a crazy person and says that there's no possible way that this problem just started. And, I know this just started... I spend a tremendous amount of time in the kitchen and I KNOW this is a NEW situation. I am really angry about this because of his response to my problem. He laughed at me and said there's no way this just started. I think I may need to call another plumber. Thank you for your help. I will certainly let you know.