General maintenance and inspection (owner check)

What is going on

These are the checks a homeowner can safely do between technician visits on a C95 or C140 combi. None of it needs tools or opening up gas parts. It is mostly looking, listening and smelling. Catching a vent problem, a leak or a pressure change early keeps small things from becoming no-heat calls in January.

Likely causes

• Gas odor from a leak at the appliance or piping
• Combustibles or flammable liquids stored too close to the boiler
• Vent leaks or blocked vent screens
• Pressure creeping up toward the relief valve rating, or temperature running too high
• Slow water leaks in boiler or system piping

Check in this order

1. Smell around the appliance for gas. If gas is present, follow the gas-smell procedure in the lighting instructions.
2. Keep combustible materials, gasoline and flammable liquids away from the boiler area.
3. Check all venting for leaks. Make sure vent screens are clean and clear, since a blocked intake or exhaust stops the burner.
4. Watch for unusual noises or vibration, because those often point to air, a failing pump or a loose part.
5. Check the operating temperature on the main display and the pressure on the relief valve gauge. Boiler pressure should be 5 psi below the relief valve rating. Boiler temperature should never exceed 180°F (82°C).
6. Look for water leaks in the boiler and system piping. Report any concerns to a qualified technician.

More boiler guides

• 0-10 VDC input to modulate firing rate (Mode 5)
• Annual maintenance and inspection
• Blank display
• Boiler pressure keeps dropping / FILL shows
• Boiler shows FILL and will not fire
• Cleaning the combustion side of the heat exchanger