A boiler that fails in January costs you heat, sleep, and emergency service rates. The same repair in September is a scheduled call at standard pricing. Here is what a complete pre-season boiler inspection covers and what you can do yourself.
What you can check yourself
Pressure gauge. A healthy hot water boiler runs between 12-15 PSI cold and 15-20 PSI at operating temperature. If pressure is consistently above 25 PSI or the pressure relief valve is dripping, the expansion tank may be waterlogged.
Pilot light or burner flame. A gas boiler's burner flame should be steady and blue with a small yellow tip. A wavering, orange, or yellow flame indicates combustion problems that require service.
Water level (steam boilers). Steam boilers require a specific water level. Check the sight glass — water should be visible at the midpoint. Low water triggers automatic shut-off; very low water can damage the heat exchanger.
Bleed radiators (hot water systems). Trapped air causes cold spots and reduces system efficiency. Bleed each radiator from the top floor down using a radiator key. Stop when water flows steadily without spurting.
What requires a technician
- Combustion analysis — verifying proper fuel-to-air ratio and flue gas composition
- Heat exchanger inspection for cracks or corrosion
- Aquastat, zone valve, and circulator pump testing
- Gas valve operation and leak test
- Flue inspection and cleaning
When to schedule
September or early October. HVAC and heating companies are booked through November once cold weather hits. A pre-season tune-up takes 60-90 minutes and costs $150-$250. Emergency no-heat calls in January cost significantly more and may face next-day scheduling during peak demand.