Low water pressure usually goes unnoticed One of the most common reasons for low water pressure occurs temporarily during busy periods, for example between 7.00am- 9.00am.  Peak periods of water usage will have an impact on the water pressure, in most instances, the fluctuation will go unnoticed unless the water pressure drops below the minimum pressure required to operate a boiler or shower. An example on this would be if you were run a tap and then flush the toilet in your bathroom, while t...