Water rising into bath from the drain

[Anari]

This morning when I was washing my face in the bathroom sink, I noticed that water came into the bath from the drain. It was dirty water and gathered to about 2cm depth before draining out very slowly. The bath had not been used but the washing machine had been on at the time. This has never happened before.

I would appreciate any tips on what the problem could be?

 

[Bahco]

Sounds like you have a shared waste pipe for both the bath and washer whichis not good practice. If there is no blockage further along, the water cannot drain away quick enough and so will back up into the bath.

Either separate the wastes or increase the bore of existing waste pipe.

 

[Anari]

Thanks for the advice. But my point is that it hasn't happened before so the waste pipes must be adequately wide. How can I fix this problem. Should I try pouring some drain unblocking liquid down the bath drain?

 

[Bahco]

Try the chemical route or you could dismantle the waste pipes and clean out

 

[ChrisR]

TRy a gallon of boiling water in the bath first - dissolves gunge quite well.

 

[Expertboy]

Pour loads of neat thick bleach down the plug hole before you go to bed and leave it. In the morning pour about 3 kettles of boiling hot water down, should do the trick.