Active job

Slow draining kitchen drain, sometimes leaks, no cause we can identify

Our kitchen sink starts backing up when using hot water, and drains very slowly, it doesn’t ever block entirely, but backs up, bubbles and takes a long time to drain when used for more than 1 minute of water. We have taken out the U-bend and cleaned it out, but the issue still occurs. We would like someone to come and resolve this issue, and allow our sink to freely drain.