Thermostatic Shower Mixer Bar Controls

[morningcloud]

Hi Guys

Can someone please shed some light.
In my house all the taps have the hot water on the left, cold on the right.

The pipes which connect onto the shower mixer bar, the one on the left gets hot so it's the same as the taps.
On the mixer bar itself the left control has blue lines on it and the right control has the temperature settings on it including the 38 degree red safety button.

Question:
I always thought the temperature control knob ie. the one on the right regulated the hot water flow not the cold or does it make no difference as long as you get the desired temperature?

The reason I'm asking is because I need to fit a new bar because the existing one starts to run cold and back to hot, which is a real pain, I guess the thermostat is shot.

Thanks to anyone who can help

 

[exedon2]

No problem hot on left new shower will fit strait in.
Get something with a decent name on it job done.