Boiler repair and replacement in Gibbstown, NJ

Hot water or steam

Most home boilers circulate hot water. A small pump, the circulator, pushes water through baseboard or cast-iron radiators and back. The system is sealed and runs under modest pressure, shown on a gauge on the boiler.

Older houses sometimes have steam. A steam boiler has a sight glass showing the water level, and the radiators have air vents that hiss as steam arrives. Steam and hot-water systems take different repairs and different replacements, so say which you have when you call. If you are unsure, a sight glass means steam.

What goes wrong

No heat at all. The burner is not firing. On oil, check the tank and the reset button. On gas, check that the boiler's switch is on and look for a code on the control.

The boiler fires but rooms stay cold. The circulator may have failed, or air is trapped in the pipes. Radiators that are warm at the bottom and cold at the top usually need bleeding.

Pressure climbing or dropping. A hot-water boiler that keeps losing pressure has a leak somewhere. One that climbs until the relief valve drips often has a failed expansion tank or fill valve.

Water on the floor. A leaking relief valve, pump seal or fitting is a repair. Water seeping from the boiler's own sections or heat exchanger usually is not.

Repair or replace

A cast-iron boiler can run for decades if its water is kept clean and its burner is serviced. What ends its life is a crack in the sections or a leaking heat exchanger. On an older oil boiler, a new burner can sometimes buy years. A technician can tell you which case you are in after looking at the boiler itself.

Replacement brings choices. A new oil boiler keeps the tank and the chimney in service. A gas boiler requires a gas service to the house. A condensing gas boiler can vent through plastic pipe, but it works most efficiently with lower water temperatures, which older radiators sized for hotter water may not allow in the coldest weeks. Ask the contractor to size the boiler to the radiation in the house, room by room, not to the old boiler's label.

Many boilers also heat domestic water through a coil or a side tank. If yours does, the replacement plan has to cover hot water too.

Questions for the contractor

• Is the trouble in the burner, the circulator, the controls or the boiler itself?
• What pressure should the system hold cold, and what does it hold now?
• On replacement, how is the size worked out from the radiators or baseboard?
• Does the chimney need a liner if the fuel or efficiency changes?
• Who applies for the township permit?

What to say when you call

• Boiler or furnace, steam or hot water, oil or gas
• Roughly what year the boiler went in
• What the pressure gauge reads, or the water level in the sight glass
• Which rooms are cold, and whether any are warm
• The address and ZIP code