Boilers in Somerville, Cambridge, and Medford tend to be old, and old boilers are forgiving right up until the first cold night, when every weak part fails at once. The busiest week of our year is always the first real cold snap, and most of those calls are things a pre-season service would have caught: a sticking low-water cutoff, a tired circulator, a pilot that will not stay lit, a relief valve weeping onto the floor.
There are a few things you can check yourself before calling anyone. Look at the pressure gauge on a hot-water boiler; it should read somewhere around 12 to 15 psi when cold. On a steam boiler, check the sight glass and make sure the water level sits roughly in the middle. Walk the radiators and note any that stayed cold last season or that bang when the system starts. Look around the base of the boiler and along the piping for rust streaks or dried white deposits, which mean something has been leaking.
A professional pre-season service goes much further. We clean the burners and pilot assembly, test the ignition and gas valve, check the venting and draft, test the low-water cutoff and pressure relief, bleed hot-water systems, replace failed steam air vents, and run a combustion test to confirm the boiler is burning cleanly and not producing carbon monoxide. On oil boilers, we also replace the nozzle and filter and brush the flue passages.
Scheduling matters. September and October are the easy months to get a convenient appointment; by mid-November every heating company in Greater Boston is running on emergencies. Garcia Services HVAC takes maintenance bookings year-round, and if you had a new boiler installed by us, the first maintenance visit is free.