I have a new construction and I moved in March 202...

I have a new construction and I moved in March 2020. I have an elaborate water system with radiant floor heat, Lochinvar water storage tank and a Lochinvar WHB155N. The WHB155N, although not even a year old, has been giving me a ton of problems. It has just been turning off. The initial installer came over 3x and couldn't get it fixed. Frustrated I called the regional Lochinvar representative. They in turn had a local guy come to my house with the installer. They were there for a while, replaced a part, then left. At that time they ordered another part as a backup. Again, it stopped working. The local installer came over for the 5th time, replaced the part that they ordered, and it stopped working again. The local installer is now coming back again Monday to modify a factory setting that contractors are told not to touch. That doesn't sound reassuring at all. I told the installer, the local Lochinvar rep, and the regional one, if it breaks down again after Monday it is being completely replaced or my money is being 100% refunded.