Boilers
Boiler Diagnostic
Boiler won't fire, leaking, or losing pressure? Six Star's diagnostic checks pressure, expansion tank, circulator, LWCO, aquastat, and combustion.
When Your Boiler Won't Fire or Won't Heat
Boilers hide their failures better than forced-air furnaces — a system can look fine and still be short-cycling, waterlogging its expansion tank, or losing water pressure slowly enough that the low-water cutoff kicks in every few days. Our boiler diagnostic finds the actual cause, not the symptom.
What Our Boiler Diagnostic Actually Checks
System pressure and pressure-reducing valve. A boiler that keeps losing pressure has a leak somewhere — sometimes in the piping, sometimes at the expansion tank, sometimes in the boiler itself. We check the fill valve setting, verify the auto-feeder isn't masking a real leak, and pressure-test if the loss rate suggests it's needed.
Expansion tank condition. A waterlogged expansion tank causes pressure spikes, relief valve weeping, and short cycling. We check air charge on diaphragm-type tanks and drainage on old bladderless tanks. Wrong-sized tanks are a surprisingly common install error we catch on diagnostic calls.
Circulator pump and flow. A circulator that's not moving water fast enough will let the boiler short-cycle on limit. We check current draw, temperature rise across the boiler, and (on zoned systems) verify each zone valve is actually opening. On multi-story homes we look at air-locked risers too.
Low-water cutoff (LWCO). The LWCO is a safety device that shuts the burner down before the boiler runs dry. A stuck or scaled probe-type cutoff can either fail to protect (dangerous) or nuisance-trip (annoying). We test the actual cutoff function, not just the presence of water.
Aquastat, gas valve, and ignition. On gas boilers we verify aquastat setpoint accuracy, gas pressure at the valve, and ignition sequence. On oil boilers we check nozzle condition, electrode gap, and combustion analysis. Different fuels, different diagnostic path.
What You Get
A written explanation of what's failing, whether the repair is worth doing given the boiler's age, and honest trade-offs on repair vs. replacement. Book a boiler diagnostic today.
Ready When You Are
Schedule service or ask a question — a real person at Six Star is standing by.