Short answer
Look at the boiler. A steam boiler has a glass sight tube showing a water line and a low-pressure gauge reading in ounces or a few psi. A hot-water boiler has a combined pressure and temperature gauge reading around 12 to 20 psi and usually a circulator pump. Radiators alone can be misleading, because both systems use cast iron.
Signs you have steam heat
Steam systems boil water and send steam up through the pipes. Older Medford homes, especially those built before the Second World War, often still have steam.
- Sight glass on the boiler with a visible water line
- Radiators have one pipe connection and a small air vent that hisses
- Pressure gauge reads in ounces or 0 to 5 psi
- Banging pipes when the heat comes on
Signs you have hot-water heat
Hot-water systems pump heated water through radiators or baseboard and back to the boiler in a closed loop.
- Pressure and temperature gauge around 12 to 20 psi
- Circulator pump on the piping
- Expansion tank near the boiler
- Radiators with two pipe connections or baseboard along walls
- Bleed valves on radiators instead of air vents
Not sure it is safe to keep running? A local technician can check it today.
Call NowWhy it matters for repairs
The parts that fail are different. Steam problems usually involve air vents, pipe pitch, water level and the low-water cutoff. Hot-water problems usually involve air in the lines, circulators, zone valves and expansion tanks.
Telling the technician which system you have, or sending a photo of the boiler and gauges, helps them bring the right parts on the first visit.
Should you convert steam to hot water?
Conversions are possible but involve more than swapping the boiler. One-pipe steam radiators and piping are not built for a pressurized hot-water loop, so conversions often mean new piping and sometimes new radiators. Many owners instead keep steam and modernize the boiler, vents and controls.
Related questions
Is steam heat less efficient than hot water?
Steam systems generally run hotter and can be less efficient, but a well-maintained, correctly sized steam system with good venting can perform well. The bigger losses usually come from poor venting and oversized boilers.
Why does only my steam heat bang?
Water trapped in sagging pipes or tilted radiators meets incoming steam and causes water hammer. Correcting pitch and venting usually fixes it.
Do hot-water radiators need bleeding?
Yes, at least at the start of the season and whenever they gurgle or stay cold at the top.
Services that fix this
Steam Heating Repair
Banging pipes, cold radiators and low-water lockouts in older steam systems.
Steam heat repair in Medford
Radiator & Baseboard Heat Repair
Cold zones, air in lines, leaking valves and failed zone valves in hot-water heat.
Radiator repair in Medford
Boiler Repair
Gas and oil boilers that will not fire, lock out, leak or lose pressure.
Boiler repair in MedfordThis guide is general information for homeowners, not a diagnosis of your system. For anything involving gas, carbon monoxide, electricity or active leaks, stop and call a qualified professional.
