You might be wondering if it is really worthwhile buying online as there is the freight to consider. But don't forget that your bricks and mortar stores also have to pay freight on the parts they get - and they then pass that cost on to you, as well as their other overheads. By buying parts online you can often get steep discounts as online stores do not have to pay staff or rent for a shop front. And often they will give you free freight if the cost of your purchase is over a certain amount.
Periodically clean the interiors of the machine with water, baking soda (half cup) and white vinegar (3 cups). Run the machine without load after filling water with the above substances. All residues and deposits formed inside will be removed. If necessary consult the company representative about the preventive maintenance. In the case of new machines make use of the free maintenance service offered by the manufacturers. Remember the adage "prevention is better than cure".