Freeing stubborn tap head gear

Send a photo - or website link to a similar tap then someone will recognise the problem. There are many different types.

Come across that a few times. I happen to have one of those 'locking' adjustable wrenches

Percussive maintenance often helps. Get an adjustable on there as tight as possible & tap it around. Lots of short sharp taps work better than big whacks. Failing that, stiltson wrench. The harder you turn the more they grip, but they will make a mess of the brasswork - will it be seen afterwards?

They look useful.

They won't be seen but I am concerned about wrecking the nut completely. My adjustable spanner will not lock and will just fall off the nut.

I guess it's the mole wrench next!

My money would be on being able to separate the silver coloured extension piece from the brass that is screwed into the tap.

If you cannot pull it off then get something to go under the extension (small jawed spanner or adjustable etc) and give it a sharp upwards whack (with a heavier spanner or adjustable etc). I reckon the extension will come off with a clout or two so be ready to catch it.

You would now be able to get a ring spanner or socket on the valve.

You should then find that the brass bit is a normal tap valve. If you should need to replace that part (if it is not rewaserable) than take that and the extension piece together to the plumbers merchants so that the splines on the valve can be matched to the extension.

Do the two taps turn on in the same or opposite directions? They are opposite if, for example, the top of the tap moves away from you for on, on both taps. The off direction of rotation (should) tighten the tap body.

They do turn in opposite directions but this side should have the right hand thread.

Operative word that "should" have you tried for LH thread?

Thanks for all the replies. I have realized now that I don't need to shift the tap gear to fix the problem.