thank you all for the good advice.I took the whole unit out the other day removed the black covers and blasted the inside with a hair dryer,had to use a low heat setting so i didnt damage anything.Worked really well until the hair dryer blew up!!!!!! think your idea with the silicia stuff jrv666 will finish it off. Also discovered one of the clips on the black cap is burst so a new one off those and problem sorted...... Thanks again.
