Overall experience: Excellent!! I have an obsolete tankless water heater from lesser-known brand - Paloma - which suddenly stopped working. I called the manufacturers to see if they had any suggested repair technicians or plumbers, and they didn't have any, but they said the problem was likely one of two things - calcification in the water coils, or a worn out diaphragm (new part $45). Either way, relatively inexpensive, but the problem was finding someone with the know-how to fix it. They suggested trying my public gas - PSE&G. So I did, and he was as nice as he could be, but didn't know the system and could only make a temporary repair, which worked for a week, and then stopped again. So I called my regular plumber, and a dozen others, and none of them could work on tankless, or if they had, they didn't know the Paloma series and didn't feel comfortable tackling it. So I did research to see about replacing it with another - but the costs for a new one are around $1,000 at the low end or $8,500 at the high end - and that's without labour - and because this is an older model, I'd need to instal larger gas lines, possibly new exhaust flutes - in short: very expensive and lots of work. So I tried calling more plumbers from Angie's list and reached Carmine, who was immediately very helpful, upfront about his fees and gave a very accurate and honest assesment. He said it likely wasn't the coils, because my area has "soft" water with few minerals, so it probably wasn't the problem - it was likely the diaphragm. He had worked on many tankless heaters, and if it was a brand he didn't know, he often called the manufacturer and they would help guide him through any issues he might encounter, or as he said to make sure he wasn't "taking apart something that shouldn't be taken apart." So if I was interested, he'd be happy to come over and try working on it. He also said he didn't mean to brag, but after 33 years in the business, he knew that not many people knew how to work on tankless (he is right) and this would probably be one of my better options (he was right again -and had I called him first it would have saved me a LOT of time, research and calls to other people - and spared me taking a lot of cold showers!) So we agreed that I'd buy the diaphragm from the manufacture and have him come in and give it a try once it arrived, to save having him do two trips, and give him the manufacturer's number to call for trouble-shooting. He arrived very punctually with his son Ben and were both very pleasant, professional and down-to-business. They quickly looked at the boiler, and made a whole series of calls to Paloma and the parts people hunting down the right person who could help, and eventually found one guy who last worked on a Paloma 20 years ago. But with good humour and encouragment he coaxed the information he needed out of him step by step until he got what he needed, and then got to work. And they finished the work in under two hours! I finally have hot water again! I was so impressed by their work I had them look at a bunch of other plumbing issues for them to work on - and they approached them all in the same way - a clear, honest assesment, telling me what needs work and what doesn't and if they didn't have other emergencies that morning they would have done them all on the spot - they had all the necessary parts. So instead of paying a minimum of more than $1,000 for a new heater plus labour, my total costs were around $345, including parts - and they were super fast, professional and nice people. I will definitely use them again!