If it is a product with a multi-way valve model, the backwash will directly reverse the multi-way valve to backwash there, open the sewage outlet and close the water purification outlet. If it is a model without multiple valves, you can directly switch the water inlet pipe and the water purification pipe to backwash. Backwash not all water purifiers have, ultrafiltration membrane filter element of the water purifier can basically backwash. Backwashing is simply to wash out the accumulated things in the filter element, as long as the water outlet is closed and the sewage outlet is opened. Water purifier more backwash can extend the service life, you can also see how dirty their own water! Backwashing is also a standard to judge the advantages and disadvantages of water purifiers, you think about it, the things that are filtered down are piled up in the water purifier for years, not to say that the service life is short, think about it. So the water purifier still has to backwash.