Have got air bubbles coming up in our downstairs toilet, and the toilet drains very slowly. The sink next to it is also draining slowly and can cause more bubbles in the toilet as it drains. They both drain out of the external wall separately, and then join into the same large waste pipe down into the ground outside. So they only join into the rest of the waste system under the ground.
No noises detected from the upstairs bathroom or kitchen, although I think flushing the upstairs toilet can trigger a few bubbles downstairs.
Google suggests it's either a medium blockage in the waste pipe, or blockage in the venting. If it is the venting - what is this, where is it, and is there anything I can check myself?
Any danger of the system flooding, or is it just an annoyance?
No noises detected from the upstairs bathroom or kitchen, although I think flushing the upstairs toilet can trigger a few bubbles downstairs.
Google suggests it's either a medium blockage in the waste pipe, or blockage in the venting. If it is the venting - what is this, where is it, and is there anything I can check myself?
Any danger of the system flooding, or is it just an annoyance?