Hi - we live in an old Victorian house that is emitting a bad smell in basement when we show -and now is getting worse and the smell is strong enough to smell it on first floor (shower on second).
Can you tell me what that means?

Hi Badsmell...

Could be that you are having an issue with venting or even could be that the main drain is starting to get blocked up and is causing a back-pressure on the drain system... ;)

Have someone fill the tub upstairs and then drain the tub while you observe the floor drain. Tell us what you observe, OK?

Back to you...

Mark

If you have a floor drain in the basment that isn't used its possible for the trap on that drain to have dried up, or possibly be broken and unable to hold the water needed to block sewer gases from entering the house. And as massplumber stated it could be a venting problem causing gasses to bubble thought the water in the trap.

You know... sometimes I forget the most obvious stuff... ;)

Definitely want to check that the PTRAP of the floor drain has water in it as lilpoppa mentioned. If the trap dries out sewer gasses can eneter the home and cause the issues you describe.

If the trap is dried out pour some water now and again periodically to keep the trap wetted.

Otherwise, test as I mentioned in my first post and pop back to discuss, OK?

Mark