Toilet slow to clear

[Lincsuk]

Hi

I lived in my house since it was built 6 years ago, for a little while now the cloakroom toilet has flushed, the water level rises to the rim and slowly goes down again (but often leaving the waste behind) If I "push" the water with the toilet brush, it goes without much hasstle. When emptying the bath (upstairs), the same toilet glugs, our en suite shower now doesn't readily clear unless the tube from the plug is removed. The third toilet, shower, kitchen sink are all OK and I suspect as these are at the rear of the house are on a separate soil vent pipe. I have checked the drains via the various access point and these look to be clear,

Is it possible that the internal vent on the vent pipe in the loft space isn't working properly and this is causing a vacuum?. If so, how can I test this.

Any help or suggestion would be appreciated as we having the in laws for Christmas now and the toilets are likely to get a hammering!.

 

[ChrisR]

Common or garden partial blockage.
There are chemicals, like Mr Muscle, which can help, but the strongest is Sulphuric acid, sold as Dam Buster, or similar. Nasty stuff - burns your skin without asking.
Cheap and worth trying is a LOT of VERY hot water. Boil up your biggest pans and lob it all down the loo. Use a plunger (several good types at plumbers merchant) or try first with the loo brush.
Don't bother with bleach - waste of time and reacts with chems to release Chlorine which can make you die a bit.

 

[Bahco]

Is it possible that the internal vent on the vent pipe in the loft space isn't working properly and this is causing a vacuum?. If so, how can I test this.

Take it off and see if this cures it.

New one needed if so.