There are many debates and confusion about shower pumps, ranging from the best make to the best type and model.
In this blog we will hopefully identify the difference between a positive head system and a negative system and offer the perfect solution.
A positive head system exists when sufficient pressure is available to provide a flow at the outlet (usually a shower) under the pressure of gravity only.
A negative head system is where there is inadequate pressure under gravity to provide sufficient flow to the outlet.
In a typical domestic house the cold water is stored in the loft in a large plastic tank, this then will feed a copper cylinder, usually insulated in green or blue foam.
This cylinder is usually situated on the floor below next to the bathroom.
The key to identifying negative or positive head is the measurement from the bottom of the cold tank to the top of the outlet (usually the shower head at its highest point).
If this measurement is more than 600mm this is classed as positive head if less or actually above the bottom of the cold water storage tank it is classed as negative.
A possible solution to this issue is to use the salamander Eve Pump.
Its clever design means it can be used on both systems and can be set to three different pressure for maximum flow.