Heater smells

[wreety]

I recently turned my heater on and it's stunk of urine or sweaty socks I've checked in engine bay an no dead animals lol, this only happened after I'd had air con compressor on but now it does all the time any ideas guys
Thanks in advance

 

[ajax1976]

Fresh pollen filter and a tin of this,
http://www.halfords.com/motoring-tr...ioning-recharge-supplies/comma-aircon-cleaner

 

[wreety]

Cheers