Simple mistakes are easily corrected by writing to the reporting company, pointing out the error, and providing proof of the mistake. You can also request to have your own comments added to explain problems. For example, if you made a payment late due to illness, explain that for the record. Lenders are usually understanding about legitimate problems.
When shopping for a dishwasher, look for features that will reduce water use, such as booster heaters and smart controls. Ask how many gallons of water the dishwasher uses during different cycles. Dishwashers that use the least amount of water will cost the least to operate.