I think you're most likely right kissifer. It seemed like a completely automatic system although it apparently never threw up any alarms or problems.Maybe my system did fill but the problem is elsewhere. They never mentioned UV dye so I guess they don't use it.

Can't believe I didn't buy one in time.

Anyone got a voucher they dont want and want to sell it? :p

Hi.

I can't use my voucher until I get my aircon repaired so you can have it if you want. I've pm'd you.
Cheers
Andy

Thanks, PM replied to.