We have a spa bath and have had it for 3 years however we have not used it since last year, its almost new, we noticed last week a smell in the bathroom not a damp smell like acidy/chemical but really unpleasant, we filled the bath and run jet but still the smell is present, we have now run it several times and even put bleach in the smell seems to waft and we are now at loss to know what to do, we have been told that as it's a bath and not a hot tub we do not have to use chemicals as the water is emptied each time, can you please help. We are now at our wits end, we have run it again today and still an odour, and we have friends coming this weekend HELP!!

Thank you for any help you can give us

I assume you have used all the other fixtures in the room (toilet, sink, shower)? If not, run water at all fixtures... could be that one of the sewer traps dried up at one of the fixtures and is allowing sewer gas into the room.

If you have freezing conditions outside, it could also be a FROZEN VENT. Is it freezing outside?

Otherwise, if your weather is reasonable and you are sure the tub is the problem, then I would suggest filling the tub past the jets and buying chemicals that treat the air jet system ( could probably use bleach). Here, although not a hot tub, you still have pipes that have sat unused for a long time. It can't hurt anything to clean the system!

Back to you

Mark

Had same problem. Some of the pipes that circulate the water and air and soft PVC and over time can sag a bit, trapping water. Bacteria get a lovely bath. Get some algae control and circulate bleach in a full tub. Should help a lot.

Cause of the smell can be dry trap or trapped water inside interior tub plumbing, including the pump itself. Make it a habit to turn water ON once a week for few seconds to re-fill traps. If trap is low on water, it will allow sewer gas to enter your bathroom. Same with floor drain, shower and sinks. Otherwise, do as ma0641 suggests.

Milo