Thermostatic shower cause water in house to go cold

[monte]

hi everyone

I have a thermostatic shower on my middle floor, which when turned seems to make all the hw taps in the house run cold and to avoid this we don't use the temp valve on the shower.

the shower is now basically either running too hot or too cold. so seems like a new shower but cannot fathom why the shower makes all the hot taps run cold.

I have a condensing boiler and unventilated cylinder which is situated on opposite side of the bathroom

any ideas welcome

thanks

 

[rpm]

Might be best to reply in the other thread guys n girls.