"Sewer" odour in little-used bedroom

[944Nick]

We've used our spare bedroom this weekend and it's clear there's a rather whiffy, slightly sewery smell in there. The bedroom has an ensuite with a toilet, handbasin and shower.

All of the drains in the room appear to be flowing well, and they all have water in the u-bend pieces. This water doesn't move if the toilet is flushed (I initially thought it might be a pipe venting issue.)

I've cleaned out the drains in that room and the adjacent ensuite with drain cleaner (one designed for "slow" drains. This doesn't seem to have made any difference.

I'm now a bit stuck for ideas. Does anyone with experience of this sort of thing have any suggestions?

regards
Nick

[RV8]

There could still be trapped hair / gunk in the u bends, it's a grotty job that I've done before. Did you run the taps for about 10 minutes, the water in the U-bends can go stagnent if the water isn't replced for some time. Have you tried having a sniff and seeing of the smell can located to somewhere specific. My guess would be the back of the toilet where the soil pipe links to it, sometimes during the hot summer months they start smelling more and if there is a breeze going down the soil vent outside it can push smells around and there only has to be a slightest air gap, which may not leak moisture (ie. at the top of a join) so can't be spotted.

[Deva Link]

RV8 said:

My guess would be the back of the toilet where the soil pipe links to it,

That was certainly the cause of the same thing in our downstairs toilet - the joint looked fine, but replaced the coupling and the smell went away.

[944Nick]

Hmmm - looks like that may be the way to go.

I'll do some further investigation and report back.

Thanks both for your help so far.

Nick

[Laurel Green]

Have you checked the overflow in the shower tray (assuming you have an overflow)? If it has, pour some water down it as it's possible that the water has evaporated.

[944Nick]

There isn't an overflow in the shower. My current thoughts tend towards the suggestion given earlier about the joint between the base of the toilet and the soil pipe. The bulk of the pipework is hidden in a boxed section covered in tiles, so I think I'll try sealing the visible joint first and see if that changes anything.

Nick

[944Nick]

I'm hoping I may have cracked it with a visit to the loft. The vent pipe from the soil pipe had become disconnecred from the roof vent.

Reconnected it now with a couple of cable ties to hold it in position. Hopefully that's it resolved. I'll let you know.

Nick