So I have had an issue that just started happening today. I noticed it first in my master bath but then realized it was happening with the showers and sinks in the both bathrooms and the kitchen sink. The water coming out of the cold taps is lukewarm. The hot seems to be fine. Apparently there is some kind of hot cold crossover occurring. I did some troubleshooting based off some topics I have read online. I went through and shut off the valves on my washing machine and turned on the taps to see if that was maybe causing the issue. Then I shut the valves off for each sink and ran the other faucets to see if one of those maybe the issue. It has been hot here lately, but I notice when I leave the water on the cold side and move it to hot, it will briefly become cold ( what I am normally use to ) before heating up. My hot water heater appears to be working ok. It is a natural gas hot water heater. My faucets in the kitchen and bathrooms are single handle delta faucets, Something I haven't done is turn the valves off on the bathtub faucets. They are both kohler faucets and both are the pull out type that turn both ways, I guess that will be my next step, but I pulled the plate off the wall in the master bath and it was pretty tight and I couldn't really figure out turn anything off. I may try to get a plumber to assist, but I wanted to run it by the experts on here to see if you may have any advice. I have been in the home for a year and there have been no modifications to the plumbing system and nothing is leaking as far as I can tell. The only odd thing is that in the guest bath the cold and hot in the tub are reversed ( Cold is left and hot is right ), but it was that way when I moved in and as I mentioned, there have never been any issues up to this point. Thank you in advance for any suggestions you may have.



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Is there a hose bib near where the main water line enters the house? Turn off the cold feed to the water heater and see if water still stays lukewarm?