I can offer a little bit of help, but not much. My first guess would be the mixing valve in the kitchen faucet is bad. As the water gets hotter and expands in the hot water tank the hot water side pressure is going to be greater than the cold water side. It might be possible the water is pushing into the cold side via the kitchen faucet. This would make sense why it returns to normal once you run it for a little while. It also explains why your filtered water is hot since it is connected to the same cold water supply pipe under the sink.
We changed all of our sink faucets a couple of years ago so I no longer have the originals and cannot share much more than theory. Hope this helps.
With best regards,
Sailing Vessel - Cream Puff - SM2K - #275
Currently cruising - Vista Mar, Panama
main@AmelYachtOwners.groups.io [mailto:main@AmelYachtOwners.groups.io] On
Behalf Of JOSE PRIETO
I have a problem that maybe some of you have already had, and can help me.
When using the kitchen faucet, my wife complained that the water was too hot, even in the position that she always used the mixer handle.
I went to check and realized that the water was really very
hot regardless the tap handle position. I also verify that the hot water was
returning through the cold water pipe.
Only after some time with the tap handle in the cold position did the water return to normal (cold), but it was enough to return to the intermediate position that the water overheated and the cold water pipe became hot again.
Thank you in advance.