Radiator smells, why?

[twiddlingthumbs69]

Bit of a random one I know but the radiator in one of our bedroom smells.

its a sort of musty stagnant smell.

Ive washed it down, twice. There are definitely no leaks, it only smells when it’s on. I’ve bled it, the water is clear and doesn’t have an odour. The wall behind isn’t damp. I’ve cleaned the carpet and still it persists!

we had a power flush 10 years ago so I suppose it could be sedament but they’re water/air tight aren’t they?

im completely baffled. I keep going in and staring at it, waiting for a lightbulb moment.

any ideas?

Are you sure it's the actual radiator and not the pipework under the floorboards?

Eeek I suppose it could be but I’ve lifted the carpet and it’s dry. Also checked the ceiling downstairs, below the radiator, and no sign of a leak