There's a very stale smell in my kitchen and I just can't work out where it's coming from. I suspect it may be the range cooker which is 16 years old or maybe the extractor hood. Is this feasible? They're both clean but I wonder really how clean they can be given their age. Should I be getting a new cooker anyway given how old it is? Any other suggestions of what to consider - it's definitely not the drains, it's much more of an "old" smell iyswim.