Ask a Tradesman
The shower in my en suite is only getting luke warm though the hotwater taps on the sink are fine. when i switch on the clod water tap in the sink the shower then gets hot . the shower two has
the given symptoms sound like hot and cold preasures are uneaqual if this is the case there are two options either a preasure reducing valve fitted to the cold supply or a reducer fitted in the cold supply to reduce the flow(probably less affective) If the hot is tank fed with cold being mains fed idealy you should run a new cold feed from the tank to balance the preasures.
Answered 7th Apr 2012
Mixer showers are generally set by the manufacturer quite low so they are antiscald. There should be an adjustment inside that allows you to increase the amount of hot water that flows through the valve.
Answered 26th Mar 2012
I also agree with Kevin. If it was a thermostatic mixer then running the cold water tap in the sink shouldnt make the shower temperature change. The fact that it does shows the cold and sink are fed from mains pressure cold and hot is fed by loft tank pressure.
Answered 4th Apr 2014
I agree with Kevin, there does seem a simple pressure imbalance going on there. You need to find out how both hot and cold are fed and then rectify, bottom line they must be relatively equal
Answered 20th Feb 2014
It almost certainly is a case of the hot supply to the mixer being tank/cylinder fed and the cold being mains fed.
Ideally, removing the cold feed and replacing it with a feed from the same cold tank as where the hot cylinder is fed from (ensuring equal hot and cold pressures and flow rates being delivered to the shower) with a plus point of being able to install a twin impeller pump in line with the mixer to drastically increase the pressure to the mixer shower.
If you do go down the twin impeller pump route though, make sure you install either a Surrey or Essex flange to the hot water cylinder to ensure an air-free supply to the inlet of the pump - failing to do this will invalidate any pump warranty in most cases.
Best of luck
Dave - DrainMedic
Answered 1st Jan 2015