Today, I returned the Westinghouse Tankless Water Heater that we purchased from Home Depot in October 2017. On 07/12/18, I hired a professional plumber from Mr Rooter Plumbing to come to our home and asses the requirements to get our Westinghouse unit up and running. As requested, he brought a brand new combustion analyzer and also a manometer and then called the Westinghouse Water Heating technical support number as directed for technical issues relating to our unit. He has informed me that the technical support staff that he spoke to were very rude and disrespectful. He followed their instructions very carefully and several times, but he received the same result, that there was something keeping the unit from firing properly at the right parameters. He was told that the unit would not be replaced and that he must be doing something wrong. He was able to get the unit to fire upon water demand but only at a very high mixture of 23+ percent. When he adjusted the unit down to 10.3, it would run, but not restart on its own upon water demand. The technical support staff told him to leave the unit on at 23+ and close it up. My plumber knew that this was not appropriate for the unit to function properly, or a way to leave a customer's appliance. I am furious by the outrageous direction of the technical support staff. I will never purchase another Westinghouse product and I will council everyone I can to do the same. From several reviews that I have read online, others have had similar issues.