When the house goes cold, our 24/7 line is open, and the first thing to do is check for danger. If a carbon monoxide alarm is sounding or you smell gas, get everyone outside and call 911 or your gas utility's emergency line before you call us. If the boiler is simply off and the house is chilling, keep faucets dripping on exterior walls and call.
Boiler repair in Braintree, MA means finding why a hydronic or steam heating system has stopped delivering heat or has started leaking, and fixing the water and gas side that licensed plumbers handle. That includes piping, valves, diverters, circulators, expansion tanks, and pressure relief. This page explains what we repair and where our scope ends.
No heat and the temperature is dropping
A boiler that has stopped heating on a freezing night puts your pipes at risk as well as your comfort. Blue Hill, the nearest federal weather record, averages about 121 days a year with lows at or below freezing, and 48 inches is the design frost depth in the Massachusetts residential code. Pipes in exterior walls, garages, and crawlspaces are the first to suffer.
While you wait, open cabinet doors under sinks on outside walls, let a faucet drip, and keep interior doors open so heat spreads. Do not use an oven or a camp stove for heat. If a pipe has already frozen, shut the main valve and see our burst pipe repair page.
- Check that the boiler switch, thermostat, and breaker are on.
- Look at the pressure gauge and note the reading.
- Do not open the boiler cabinet or the burner.
- Never bypass a safety cutout or a relief valve.
What boiler repair covers, and what it does not
Plumbing and gas fitting are regulated by the Board of State Examiners of Plumbers and Gas Fitters, and we work within that scope. That covers piping, valves, circulators, diverters, air vents, expansion tanks, relief valves, fill valves and leaks. Oil burner work is separate. The Department of Fire Services issues its own oil burner technician certificate through its Boiler and Pressure Vessel program, covering service, installation, and repair of oil burners.
That means if your fault is in an oil burner, the nozzle, the primary control, or the fuel unit, the right person holds a different certificate. We tell you early which side the fault is on, so you do not pay for a visit that cannot fix it. Ask any company who will handle each part before work starts.
House getting cold?
Call (617) 752-0573 and tell us the system type. We take after-hours calls and book same-day visits when available.
Boiler symptoms and the plumbing side of the cause
This table covers faults a plumber traces. Burner-side faults are noted so you know where they go.
| What you see | Plumbing side cause | Other cause to rule out. |
|---|---|---|
| Radiators cold, boiler running. | Air in the lines, a stuck zone valve, a failed circulator. | Thermostat or control wiring. |
| Pressure gauge too high or too low. | Failed expansion tank, bad fill valve, leaking system. | A faulty pressure sensor. |
| Relief valve dripping. | Overpressure from a waterlogged expansion tank. | Overheated boiler. |
| Water on the floor. | Leaking joint, valve packing, circulator flange, or boiler section. | Condensation or a leaking tankless coil. |
| Domestic hot water cold, heat fine. | A stuck diverter or a failed indirect tank loop. | Aquastat setting. |
| Banging or knocking pipes. | Trapped air, steam water hammer, or sagging pipe pitch. | Pump surge. |
A leak from the boiler body itself usually means a cracked section or failed gasket. That is a replacement question and not a patch.
Hydronic and steam systems fail in different ways
Older homes often have one of two systems. Knowing which yours is helps both of us.
Hot water baseboard.
Water circulates through copper pipe and finned tube. Air pockets, a dead circulator, and stuck zone valves are the usual plumbing faults.
Cast iron radiators on hot water.
Heavy radiators with air vents at the top. A radiator that stays cold at the top usually needs bleeding or has a failed vent.
One pipe steam.
Steam rises to the radiator through a single pipe and the condensate returns through the same one. Slope, vent valves, and water level are everything.
Two pipe steam.
A separate return carries condensate back. Failed traps and clogged returns cause banging and uneven heat.
Low water cutoff and sight glass.
On steam boilers, the water level in the sight glass is the first thing we read. A low reading shuts the boiler off, and a blow down of the cutoff keeps it reliable.
Indirect water heater loop.
Many boilers also heat an indirect tank. A failed diverter or loop circulator takes the hot water down with the heat.
How we trace a boiler with no heat
We work from outside the boiler in, so we do not take apart a working unit.
Read the system.
Gauge pressure and temperature, the sight glass on steam, and any fault light tell us the state before we touch a valve.
Check flow and zones.
We feel pipes at the circulator and zone valves, bleed air from the lines, and confirm each zone calls for heat and gets it.
Test the water side parts.
Expansion tank charge, fill valve, relief valve, diverter, and air vents are tested or replaced as needed.
Hand off or finish.
If the fault is on the burner side, we explain who to call. If the fault is ours, we repair it, restart the system, and confirm every zone heats.
Older Braintree houses and what we watch for
The median Braintree home was built in 1957, and about 27 percent of homes date to 1939 or earlier, according to Census survey data. Homes of that age often carry old steel or galvanized piping, radiators plumbed decades ago, and boilers that have been patched more than once. When we find a pipe thinning at a joint, we tell you now, so you can plan before a winter failure.
Leaks that run for weeks quietly raise your water bill, since the fill valve keeps topping up the system. If your bill rose without a clear reason, mention it, and our leak detection team can check the rest of the house.
What decides the cost of a boiler repair
A diverter swap and a leaking section sit far apart in price. Call (617) 752-0573 and we give a clear price before work starts.
Boiler failures from age or wear are rarely covered. Sudden water damage from a burst pipe may be, so document everything and contact your insurer before repairs begin.
Boiler questions in the middle of a cold snap
Yes. The dispatch line takes calls overnight and on weekends, and we book same-day visits when available. Tell us whether it is hot water or steam, what the gauge reads, and whether the burner is running.
Oil burner service, installation, and repair is licensed separately through the Department of Fire Services. We handle the plumbing and gas side, and we tell you quickly which side your fault is on.
A waterlogged expansion tank or a faulty fill valve is the usual cause. Do not open the relief valve to vent it. Call, because a stuck relief valve can scald.
Trapped air, a stuck zone valve, or a failed circulator are common. Bleeding the radiator helps only on hot water systems. Do not bleed a steam system.
A leak from a joint, valve, or flange can be repaired. A leak from the boiler body usually means replacement. For related work, our water heater repair page covers indirect tanks, and we serve Quincy nearby.