A Warren Woods homeowner near 13 Mile calls because the boiler has been adding water every day. The automatic feeder clicks on, fills, and a day later it is at it again. Quick observation first: no puddle under the boiler, the sight glass looks normal, and the gauge is fine. That water is leaving somewhere we cannot see yet.
We follow the wet return. In these late 1950s and 1960s colonials, the wet return runs low along the floor, stays full of water, and rusts from the inside out. We look for a damp line on the concrete, a crusty fitting, or a section buried behind a finished wall. We also check the Hartford Loop tee height at the boiler and look for steam escaping from a vent or valve upstairs.
Sometimes it is not a leak at all. We have found the feeder itself passing water past a worn valve, or a valve left half open after somebody's maintenance visit. Every fix starts with the cause. Replacing a feeder that is doing exactly what it should only hides the real leak until the boiler floods or runs dry.
Once we find it, we show the homeowner the failed pipe or fitting and price the repair in writing. A wet return or fitting leak is a pipe job, not a boiler job. We refill, skim if the fresh water stirred up the system, and recommend logging the water level weekly so the next change gets caught early.