We had a very cold night, set a record for southern az, 5 degrees. For awhile the kithcen sink had no flow, the master bath had no flow. It's been in the seventies for over a week now and everything flows normally except the bathroom sink, no hot or cold at all. Zero. The pipes run through the insulated ceiling and we'ver searched everywhere for a leak. No leaks detected. Makes no sense at all. I am baffled.

Hi Wassamatau...

First thing to check in these cases is the AERATOR at the end of the spout... could be totally plugged from sediment that got released when the pipes thawed out.

Unscrew the aerator, clean the aerator and before putting it back in place run the hot and cold water to purge any other sediment that could reclog the cleaned aerator and see if water flows. If water flows then reinstall the aerator and you are all set!

If water doesn't flow then the next step would be to disconnect the supplies under the sink and see if water is flowing past the shutoffs below, OK?

Back to you...

Mark

I am with Mark on this, especially if the toilet and the tub/shower are working in this room