Fast, punctual and reasonably priced. We have gone through quite a few plumbers and hot water heating specialists over the years and there were always nagging issues like the valve stem on the hot water heating inlet control was leaking, laundry tub supply leaks, etc. The contractors came and did the main job but when asked about the odd bits, they would ignore it or do a temporary patch.
Mermaid on the other hand came out to service a leaky hot water tank and address any and every issue that they saw. Mermaid did more than we asked, did it faster than any plumbers we dealt with in the pass, address not only the problem but the cause of the problem and handles both plumbing and hydronics.