Sewage Smell / Flushing = Gurgling Shower Trap

[rossyl]

Hi All,

1st floor Bathroom newly refitted 2 years ago. Never had an issue.

Now have a sewage smell.
More recently shower trap now gurgles when toilet is flushed.

Waste runs a short distance to a 3 storey stack, that goes up beyond the ridge line. I can't see the top but (I presume) has a vent at its top.

Toilet is a wall hung pan. Fully tiled wall.

There are two bathrooms on the floor above. They use the same waste. They have AAVs fitted just behind them, and are a much longer run to the waste.
They have no issues.

Grateful for thoughts on what the cause might be and beat way to go about sorting.

Many thanks

[BlindedByTheLights]

Chuck a load of drain cleaning gel down it in the first instance and see if that clears it first

[Slagathore]

Sounds like siphoning:

https://theplumbingteam.co.uk/u-bend-plumbing-expl...

But seems strange if the system has all the usual AAVs etc.

Is the shower waste accessible? I'm sure I've seen anti-siphon wastes somewhere?

[rossyl]

Nothing is accessible, unfortunately.

I don't think the shower drain is blocked.

[essayer]

Lift inspection covers and check for blocks, ours does this when the drains are backed up

[Baldchap]

My money is on a blockage between the toilet and the sewer, after the point where the shower drain joins it in the bathroom or at the soil stack.

If you have Homeserve or something they'll come and run a camera to see where the blockage is.

[Ham_and_Jam]

rossyl said:

Nothing is accessible, unfortunately.

I don't think the shower drain is blocked.

Does the shower drain into a separate hopper / drain? If it does you won’t see the problem.

We had the same gurgling issues, it was a problem in the main sewer which was causing a blockage. This only manifested itself with the bath / toilet which emptied into the main soil pipe.

Try all the easy stuff you can do yourself first. If that fails get the drain people in to see if they can unblock it, or put a camera down to inspect.