Plumbing - no cold water from cold water tap

Hi blondi_1452,

I'm Harvey the Master Plumber.

Your question is: Why would the cold line water be luke warm?

In 30 years I've seen this maybe 10 times. It is relatively rare. But each time it was a cross connection between the hot and cold water lines. It could be this fixture is close to the hot water heater or the cross cnnection is in a faucet or it is in the way the water lines are piped. Anyway I would have to closely inspect the system while running the water in the fixtures in different combinations. Once the cross is located the easiest fix at this point is installing a check valve at the right point. You might consider utilizing thr Repair Directory to find a repairman. Make sure he has solved this type of problem before.

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Thank you,
Harvey your Master Plumber

Does the cold water pressure appear less than the hot water pressure?

If so, it is possible that the hot water is bleeding into the cold water particularly if the hot water pressure is higher than the cold.

Could the outside mains water tap have been turned down reducing the cold water pressure?
Is the hot water temperature high enough to cause higher pressure?

Could there be rusting in the main or cold water pipe causing restriction?

More than likely its to do with the pipes being in direct sunlight causing pipes to warm water,or they may be inside a wall wich faces the sunlight doind the same.your nieghbours pipes may be longer than yours allowing it to cool by the time he recieves from tap. some sort of shading on pipes or wall may help with your prob. good luck