Shower Mixer Problems

[GeordieJam]

Hi All - any assistance gratefully recieved!

Just moved into a new house built in the 1930's which has a shower mixer attached to the bath. The system is a combi (I believe)

The problem is, even though the water pressure seems OK (at least to me!) the toggle/ plunger for the mixer will not stay in the shower position and water still comes through the taps rather than the shower head. I believe the model is Twysords but unable to locate on web

Is this a problem with mixer?
Problem as property had not been used in several weeks?
Problem with water pressure?

What should I do to repair

Thanks

 

[ChrisR]

Maybe Twyfords?
usually, dismantle, not always easy, replace O ring, reassemble and you fnd it hasn't made much difference.

Look for a replacement gubbins at http://www.lunns.net/