Powermax blending valve

[hughesy]

Hi,

The hot water coming out of my taps is scalding hot, apparently this is due to either a blocked or incorrectly adjusted blending valve. I've had a look at the valve, there is a black plastic cap with a + and - on. If this is removed there is a square drive "key" which way do |I turn this to decrease the temp of the water?
Should I be able to turn the temp down using the black plastic cap? Do I need a new blending valve of can they be serviced/adjusted?

Thanks in advance for any information

Hughesy

 

[Sider]

Just try turning it one way or another and see what happens.
It sounds as though it cant get any hotter.