Boiler repair covers the diagnosis and fixing of a heating boiler that heats water or makes steam for radiators, baseboards or in-floor loops. Common faults include no heat, banging pipes, a leak, a pressure gauge that reads too high or too low, and radiators that stay cold at the top. Milton Pro Plumbing offers same-day appointments when available and states a clear price before work starts.
Questions people ask before calling about a boiler
Air trapped in a hot-water radiator is the most common cause, and bleeding it is a safe homeowner step. If every radiator is cold, the cause may be a failed circulator pump, a closed valve, low system pressure or a thermostat that is not calling for heat. A plumber can sort out which.
Many residential hot-water boilers sit near 12 to 15 psi when cold, but your boiler's label and manual decide. A reading near zero suggests a leak or lost water. A reading that climbs toward 30 psi means the relief valve may open, so shut the boiler off and call.
It is a warning, not always a crisis. Banging in a steam system often means water is trapped in a pipe that does not slope back to the boiler. In a hot-water system, kettling noises point to scale or low flow in the heat exchanger. Either one deserves a visit before the cold season.
Licensed plumbers handle the water side, including piping, valves, pumps and expansion tanks. Work that touches gas piping or burners involves gas fitting licences. Ask who is licensed for each part, whether a permit is needed, and ask to see it. Ask the Milton plumbing inspector about local rules.
Leave the home at once and call 911 or your gas utility from outside. Do not turn lights or switches on or off, and do not call a plumber until the utility says the building is safe. Carbon monoxide alarms should be working on every floor.
A steady leak is urgent. Turn the boiler off, close the water feed valve to the boiler, and put a container under the drip. Small weeping at a valve can wait for a same-day appointment. If water is spraying or pooling fast, call now and see our burst pipe repair page.
Yes. A steam boiler carries a water level that has to be kept right, and its radiators have air vents instead of bleed valves. Do not bleed a steam radiator with a key. The table on this page compares the two systems.
Call with the address and a contact for access. Tenants without heat in freezing weather should be treated as urgent. The plumber will say what the visit can fix, and you can arrange any follow-up work in the building.
Rather talk it through? Call and ask a plumber.
(617) 752-0573What the symptoms usually point to
Boilers tend to fail in recognizable ways. Matching the symptom to a likely cause gives you a better call to the plumber and a faster fix.
- No heat and no hot water: a tripped switch, a lockout, a dead ignition or no fuel.
- Heat in some rooms only: trapped air, a closed zone valve or a failing circulator.
- Banging or gurgling: air in the loop, scale, or trapped water in steam piping.
- Puddle under the boiler: a weeping valve, a failed gasket, or a corroded heat exchanger.
- Gauge that keeps rising: a failed expansion tank or a feed valve stuck open.
- Pressure that keeps falling: a leak somewhere in the system, including inside walls.
Steam and hot-water boilers compared
Knowing which kind of boiler you have decides what you can safely touch.
| System | How it heats | Radiator valves | Homeowner can do | Leave to a plumber |
|---|---|---|---|---|
| Steam | Boils water, steam rises to radiators and condenses back | Air vent on the side or end | Check the water level glass, clean around vents | Low water cutoff, skimming, pipe pitch |
| Hot water (hydronic) | Heated water is pumped through radiators or baseboard | Small bleed valve | Bleed radiators, check pressure, set the thermostat | Pump, zone valves, expansion tank, leaks |
If you cannot tell which you have, look for a sight glass on the boiler for steam, or a pressure gauge and circulator pump for hot water.
Questions about boiler repair? Call a plumber
Licensed plumbers are dispatched day and night, and you hear the price before work starts.
Bleeding air from a hot-water radiator
Do this only on a hot-water system, never steam. Turn the heat on, let the radiators warm, then turn the boiler off before you start.
Find the valve
It is a small square or slotted fitting near the top corner of the radiator.Hold a cloth and cup
Water may spit out after the air, and it can be hot.Open a quarter turn
Use a radiator key. A hiss means air is leaving.Close when water appears
Shut the valve as soon as a steady stream of water follows the hiss.Recheck the gauge
Bleeding drops system pressure, so confirm the gauge is back in its normal range.
Why Milton houses and boilers go together
The 2020 EIA Residential Energy Consumption Survey found that 26% of Massachusetts homes heat with a steam or hot-water boiler, while 55% use furnaces. In Milton, where 46.8% of homes were built in 1939 or earlier and the median home is 71 years old, many houses were built around radiators. If your home has them, your boiler may be older than the typical statewide unit, so treat noise and rust as early warnings.
Licensing and permits for heating work
Plumbing work in Massachusetts must be done by a licensed plumber, and gas fitting has its own licence under the Board of State Examiners of Plumbers and Gas Fitters. Heating work that touches gas piping or burners therefore involves gas fitting licences, and some jobs also involve other trades.
Ask the plumber who is licensed for what, whether a permit is required, and to see it. You can check any licence in the state eLIPSE portal. For local specifics, ask the Milton plumbing inspector. The standard that governs this work is the Massachusetts Uniform State Plumbing Code, 248 CMR 10.00, and gas fitting has its own licence under the same Board.
What affects the price of boiler repair
The plumber gives a clear price before work starts. Several things move it.
The fault
Bleeding a loop is a minor visit, while a pump or heat exchanger is a larger job.
System type
Steam systems have different parts than hot-water ones.
Parts availability
Older boilers may need parts that take time to find.
Gas or burner work
Gas fitting work adds licensed labor and testing.
Age and condition
A boiler near the end of its life may need repair or a replacement plan.
Homeowners policies often cover sudden and accidental damage but usually not wear or maintenance. Policy wording decides, so read it or ask your insurer.
Nearby and related services
Burst or frozen pipes after a heat loss are handled on the burst pipe page, and hidden leaks can be traced with leak detection. We also serve Randolph homes with older heating systems.