Turn on cold faucet in main bathroom and hot water comes out

Could be a cross connection somewhere or a crossed line under the sink. What comes out of the hot water tap and does the water ever get cold on the cold tap?

If I let the cold faucet run long enough the water does go cold and hot water comes out of the hot faucet as normal

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Originally Posted by ma0641

Could be a cross connection somewhere or a crossed line under the sink. What comes out of the hot water tap and does the water ever get cold on the cold tap?

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If I let the cold faucet run long enough it does run cold. Regular hot water comes out of the hot faucet. To note: this is occurring in two sink vanities in the same bathroom.

Do you have a hot water recirculating line?

Yes and I just noticed it is in the powder room vanity sink as well. So, is it a sensor at the recirculating pump? If so can I fix it or do I need to call our plumber?

Probably the check valve. The one on the cold water input pipe to the water heater, that prevents the recirculated hot water from going back up the cold water line.

Is the pump running properly?

Do you have a stop valve on the recirculating line?

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Originally Posted by hkstroud

Probably the check valve. The one on the cold water input pipe to the water heater, that prevents the recirculated hot water from going back up the cold water line.

Is the pump running properly?

Do you have a stop valve on the recirculating line?

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Yes, the recirculating pump is working properly. I don't know what or where a "stop valve" looks like or where it would be. I am going to have a master shut off valve installed in the house, wouldn't that be the time to have the check valve changed? Especially, because it sounds like I would need to turn off the water to the whole house.

Yes, that would be the time to change out a failing check valve.

However if you have a stop valve on the recirculating line you can close it and that will stop hot water from entering the cold water line. It will also confirm that the check valve is defective.
It will also stop the recirculating line from functioning. The pump should be shut down if you close that valve.

Look at the pipe that the pump is connected to (recirculating line). Is there a valve on that pipe, either before the pump or after the pump but before the recirculating line connects to the cold water input line?

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I am going to have a master shut off valve installed in the house,

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Could you explain? Very unusual to not have a stop valve on the main line coming in to the house.

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Originally Posted by hkstroud

Could you explain? Very unusual to not have a stop valve on the main line coming in to the house.

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We have a stop valve in the crawl space. We were going to have a much more convient location installed. Back to the recirculating pump, there is a stop valve on the pipe going into the water heater, that is the only valve of any kind the a pipe coming out of the water heater then the pump. Now it could function the other way, pipe to pump to heater to pipe to valve then pipe into wall

Can't tell from description. Post a picture of pipes.

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Originally Posted by hkstroud

can't tell from description. Post a picture of pipes.

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OK.
Pump is on hot water out pipe. Don't see the recirculation (the line that returns the hot water to the tank). Is there a pipe that connects to the drain pipe at the bottom of the tank.

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Originally Posted by hkstroud

OK.
Pump is on hot water out pipe. Don't see the recirculation (the line that returns the hot water to the tank). Is there a pipe that connects to the drain pipe at the bottom of the tank.

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Floor shows return pipe with a T connector and the drain spout.
The other 2 show the brand of pump, I wonder if whatever valve has failed is in the pump itself behind the plate on the back. I'm afraid it's looking like a failed pump. Do you agree?