Called them to fix 3 year old boiler that did not work. They charged me $ 360 for first visit, and said they need to order the part. Ordered it, installed - unit did not work anyway. Only after this they measured CO, said its too high, put a reg tag on unit, charged me another $160 and left without any written report re reasons of unit failure. They said they need to investigate further - but refused to provide quote for extra cost they will charge. But they offered to quote a new boiler - if I want to replace a 3 year old one. So after $520 expense my unit does not work and I have a part I do not need. In general, I was under impression thy had no clue about how to deal with this boiler, but it was a manufacturer who recommended them. Do not use them - they will overcharge you, and do not use Slant Fin in Canada - they are not supportive and rude.