Persistent smell

[blizzardkaren]

There’s a persistent smell in my living room that I can't find. It's a musty smell suggesting mould/mildew. If I spend too long in the living room with the doors closed to keep it warm, the air gets too heavy to breath within a couple of hours.
I've checked and cleaned everything including chairs, carpet, rug and curtains. House is generally not dirty. I vacuum fortnightly and there's nothing in other rooms that would transfer a smell into the living room. I've taken everything off shelves, checked and smelled it. I've moved all furniture, smelled and cleaned under and around, even moving a huge wall unit to get behind and under it.

I've been on my hands and knees and smelled every square foot of the house to find the source. I've even smelled the floor and been up at the ceiling as I'm the middle of three flats, one above and one below. I've found absolutely nothing. No evidence of mould or mildew or strong obvious source of smell at all. I've aired the whole house for full weekends and within a couple of days the smell is back.
This is causing me serious embarrassment because the smell gets on my clothes, wet or dry. I've changed washing liquid and fabric conditioner and cleaned the washing machine and run it on 90 degree cycles with white vinegar to disinfect. It also isn't coming from any drains or the bin.
I have a dehumidifier which I've been running all day and overnight since December. It hasn't solved the problem. It isn’t the plant I have here, moved it to another room to test, smell was still in the living room.
Please can someone help with suggestions? The smell is causing misery, potential health problems and a lot of embarrassment.

vacuum fortnightly i vacume everyday...

We've been having that and got dynorod out, and it turned out to be a cracked sewage pipe (Victorian house).

Could the smell be your drains /sewage? Even if it's not near the kitchen or bathroom the fumes could still make their way to your living room.

The problem is made worse by conserving water!

I know you’ve checked floor and ceiling but maybe check the flats above and below?

@whilethechiefputsshineonleith Thanks for the mild shaming but I don't have time to vacuum every day and it isn't a vacuuming problem. The smell returns fairly quickly post-cleaning.

@SureIusedtobetaller No, I haven't, neither couples are the sort to be amenable to me knocking on the door asking if their flats smell, sadly.

@crosspelican This place was only built in the mid-80s but that is 30+ years ago now so could be an outside option. Bearing in mind I have crawled around and methodically smelled all of the floor with no telling result. None of the pipes from bathroom or kitchen go near the front room and it doesn't really smell like sewage. I'm sure the guilty room would smell when I have all the doors closed. I'll get the pipes done anyway just in case.

We had a room in our house with a persistent smell. We'd only just moved in and didn't really have much furniture or anything that could be the cause. Eventually we re-painted the room and that sorted it. No idea how the actual walls could smell though!

Also (just a thought)... Have you got any one else to check if they can smell it and where its coming from? DH is convinced the back of our fridge smells. He's always going on about it. But I can't smell anything at all. I think it's just become a 'thing' in his mind now.

@Wavingwhiledrowning Been able to smell it since August and g/f said she could not smell it when she last visited (October) but she is sometimes overly polite. Ironically, I don't think it smelled when she was here either, so I'm trying to work out what was different. I didn't clean any more than usual or move anything into a cupboard or anything like that. Can't repaint as it's a rental (landlord says he can't smell anything but that's landlords...), have already wiped down the walls with a mix of vinegar, water and washing up liquid. Could give that another bash?

Sorry if it seems like I'm naysaying every suggestion, please do keep them coming, I appreciate them. That's the reason for posting, it really is a mystery to me.

I have a simular issue. We fitted our new home and replaced every thing yet at the top of the first flight of stairs that leads to the kitchen it stinks. Smells fousty. Like a really dirty house. I have a cleaning OCD and a weekly cleaner. What could it be.

Is it fishy at all?
If it is it could be an electrical fault.
Have you checked all the switches and sockets?

Could it be mice?

My vote would be a decaying 'something' under the floorboards. (We had a couple of dead rats and the smell was vile, so maybe yours is a bit smaller, like a mouse.)

I was going to say what endof just said. If it's a fishy smell check things like light bulbs. Electrical faults can cause a horrendous smell.

blizzard
That sounds like you have a damp/ventilation problem if your clothes smell of it.
My bil/sil do and they reek of damp 😞
No obvious signs of it in their house.
Can you get someone in to check the walls?
Ps I have my windows open throughout to "air"

Damp is terrible for making your clothes smell.

You need to get someone to come over when the smell is apparent. If they can't smell it are you sure it's not a sinus infection? I know that sounds ridiculous but it can cause an awful smell in your nose and would explain why you can't find the source. It also would explain why you find the air heavy when the doors are closed

Thanks all. I think either the dead something under the floors or damp in the walls could be a good call. Dehumidifier is hardly picking anything up now, less than a cup for a full day, but that's possible.
When I finally get to the bottom of it, I'll report back!

Not able to have my windows open during the day to air as it's only me living here and I work full time.
As for sinus infection, definitely not. I did wonder, but it's only in here, I don't smell it anywhere else and it's been months.

Are you drying your clothing in the flat rather than outside or in a drier?

Old underlay can smell, even if the carpet is clean. In fact if the carpets have been cleaned and made too wet, that can cause mould in the underlay.

My neighbour has a musty smell, dampish, in her house, she rarely opens the windows. Double glazing with no vent or air, a damp external wall, badly fitted windows that let in water... or damp under the floor/flat below or above.

Dead critters don't tend to smell like damp, more like rotting flesh or cabbage depending on the stage of decomposition and it tends to be gone in about 6 weeks. Damp fluctuates in smell with the temperature and weather.

What kind of windows do you have? If they are casement ones you may be able to get handles for them which lock while keeping them open just a fraction, which may help.
If the dehumidifier was picking up a lot of liquid to start with, but now less, it does sound like it could be a ventilation issue- possibly now having made the carpet underlay musty. Although you'd have thought sniffing the floor would have shown that up?? Argh!

I would call a drains expert too, and if that doesn't work, move flat.