In article ,
John Andrews wrote:
Thanks for your ideas. I guess with (1) I can have a go at
disassembling to check it out. There is a vent, so that takes (2) out
of the picture, right?

These can block. Check there is water there by partially dismantling.

--
*Sometimes I wake up grumpy; Other times I let him sleep.

Dave Plowman London SW
To e-mail, change noise into sound.