Notice the signs
Observe
Check representative fixtures without dismantling them and record cold flow, hot-side flow, wait time, temperature trend, recent demand, error display, utility interruption, recirculation behavior, and whether the heater is leaking.
Protect the room
Safety line
For gas odor, leave rapidly and call 911 from outside. Avoid opening panels, resetting repeatedly, relighting, bypassing controls, touching wet power, or increasing temperature to compensate for an unknown fault.
Material note
Local boundary
Utility service, appliance diagnosis, plumbing distribution, gas fitting, and electrical work are separate authorities. Cohasset permits and inspections depend on the actual repair or replacement scope.
Service flow
Written scope
Require the diagnostic visit to identify included fixture checks, measured temperatures, demand assumptions, control tests, fuel or power handoff, repair options, service charge, and the point where replacement pricing begins.
Close the loop
Verification
Retest the same representative fixtures after a full recovery period, under a known demand, and document final settings, error history, delivery time, and any component or trade not addressed.