In a hot water pressure washer the design inlet temperature should not be exceeded as it may affect the seals in the internal machinery. The size of the motor that drives the pump to produce the water pressure. The motor size is normally expressed in Kw for an electric washer and HP for an engine driven version. The motor must be correctly sized to match the pump to ensure optimum performance. On cheaper machines the pump may be smaller than the ideal size meaning it has to work harder to create the required flow and pressure and as a consequence will not last as long.
Pressure alone is not an indication of effective cleaning as water volume plays an important part. For instance high pressure used with a low water volume will produce a powerful but narrow water jet which may be ideal for cleaning small areas of ingrained dirt but not so effective for cleaning larger areas with a lot of debris to be removed. In this situation a pressure washer with a larger water volume cleans more efficiently.
Pressure washers (jet washers) are an invaluable cleaning tool and like many things once you have used one you will wonder how you managed without it but what is a pressure washer? It basically comprises a pump a high pressure hose and a cleaning lance with a trigger switch. Water is passed through the machine and put under pressure by the pump and expelled via the hose and out from the nozzle at the end of the lance. On the face of it quite a simple machine but selecting the right pressure washer is a different matter.