Boiler repair: common problems, upkeep and repair vs. replace

How a boiler works

A boiler heats water and sends hot water or steam through pipes to radiators or other heat emitters (DOE). The Department of Energy says up to 11% of U.S. households use hot water or steam heat (DOE).

Warning signs to call a pro

The University of Missouri Extension lists these signs that your system needs professional help (MU Extension):

• Odors near the boiler
• Soot at the burner or black smoke from the chimney
• Water surging in the boiler’s sight gauge

Headaches, dizziness or nausea that get better when you leave the house can be signs of carbon monoxide poisoning (CPSC). Get everyone outside and call 911.

Upkeep that lowers your bill

• Annual service. Have a qualified technician service the system before each heating season (MU Extension).
• Radiators. Vacuum dust off them, bleed air from hot-water radiators once a year, and don’t block them with furniture or drapes (MU Extension).
• Skip the metallic paint. Metallic paint or decorative covers can cut a radiator’s heat output by up to 25% (MU Extension).
• Reflectors and insulation. A heat reflector behind a radiator on an outside wall sends more heat into the room, and insulating hot-water or steam pipes in unheated spaces cuts heat loss (MU Extension).

Repair or replace?

• Age. DOE lists a boiler’s life expectancy as 15 to 30 years (DOE). An older boiler that needs a big repair may be worth replacing.
• Efficiency. DOE says older heating systems run at 56% to 70% AFUE, while high-efficiency systems reach 90% to 98.5% (DOE). ENERGY STAR certified gas boilers are rated 90% AFUE or more, and oil boilers 87% or more (ENERGY STAR).
• Savings. ENERGY STAR estimates a certified gas boiler can save about $780 over its lifetime, and an oil boiler about $200 (ENERGY STAR). Your savings depend on your fuel prices and home.
• Safety. Sealed-combustion, direct-vent boilers bring in outside air for burning and vent directly outdoors. DOE says they’re the safest type to have in your home (DOE).
• Fix the house first. DOE suggests improving your home’s insulation and air sealing before you replace a system, so you may be able to buy a smaller unit (DOE). See our home energy audit guide.

Help paying in Illinois

• The Illinois Home Weatherization Assistance Program can fund heating repair or replacement, up to $20,000 per home, for households at or below 200% of the federal poverty level (Illinois DCEO).
• LIHEAP helps eligible households pay heating bills (Illinois DCEO). See our heating bill help guide.

Renting in Chicago?

If you rent, call your landlord first. The Chicago Heat Ordinance requires heat from September 15 to June 1: at least 68 degrees from 8:30 a.m. to 10:30 p.m. and 66 degrees overnight. Tenants can report no heat to 311, and landlords can be fined $500 to $1,000 per day per violation (City of Chicago).

Hiring a heating contractor

• Get written estimates from more than one contractor, and ask whether they work on steam or hot-water systems.
• For home repair work over $1,000 in Illinois, get a written contract and the “Home Repair: Know Your Rights” pamphlet (Illinois Attorney General).
• Don’t pay in full before the work is done.

Have a furnace instead? See our furnace repair guide and our HVAC guide.