Low water pressure from hose pipe
Outside tap water pressure can vary greatly and can be reduced by anything that impedes the follow of water through your pipework and tap. Low water pressure from hose pipe can be diagnosed by checking through the following:
Measure Water Pressure
To check for low garden tap water pressure you can purchase an inexpensive water pressure gauge to check the water pressure at the tap outlet.
Check your hose
If you have eliminated the potential causes listed below, or better still, used a pressure gauge to check you have a normal water pressure, have you checked your hosepipe? This is the biggest cause of low water pressure from hose pipe. Budget hosepipe is often subject to kinking or twisting when in use and, over a length of hose, each restriction reduces the pressure and flow through the hose. If you own a hose like this, you will recognize the story - constantly walking up and down untwisting and de-kinking the hose to get a reasonable output. The solution is simple: buy a good quality hose, such as one from the superb Gardena range of hoses and hose trolleys.
Limescale in the household pipework
A common causes of low water pressure in the garden is old pipework that is full of limescale. A run of semi-blocked household pipework can reduce output at the garden tap to a trickle; not enough to successfully feed a lawn sprinkler system. The solution here is replacement of the affected pipework.
Garden water pressure can also vary according to usage of water in your own home. You may notice that showers, washing machines, or toilet flushing for instance, can reduce pressure at your garden tap, or is even affected by consumption of water by neighbours along the street. Warm summer evenings may be particularly bad for water pressure when keen gardeners try to give their lawns and plants a drink as the sun goes down.
Mains water pressure can also depend on where your home lies in relation to the water main. Gravity plays a part here and at the top of a hill water pressure will be lower than for a property at the bottom of a valley. Remove any restrictions in your own pipework and make sure you have the best hose pipe you can afford - every small improvement helps increase the flow at the nozzle.
If your garden is has an incline then you should expect to have lower water pressure at the hose running up the slope, and an increase in water pressure at the bottom of the garden.
If you're sure that the pressure from your garden tap is good, then your hose is the most likely cause of low pressure from the nozzle or sprinkler. Treat yourself to a quality hose pipe - you won't regret it.