1-888-464-6772 inspections@insparisk.com Contact Command Network

Boiler short cycling: causes and fixes

Boiler turns on and off constantly (short cycling)

Have it checked

What is likely happening

Rapid on-off cycling wastes fuel and wears components. Common causes are an oversized boiler, poorly set controls, a failing sensor, or low flow through the system.

What you can safely check

What an inspector will look at

Does this affect compliance?

Short cycling is not a violation on its own, but it often shows up alongside control defects noted at inspection.

When it becomes urgent

More urgent if cycling comes with lockouts, noise or pressure swings.

We can help with this

Boiler inspection is something Insparisk does nationwide. To see the local rules for your building, open this in the interactive Problem Solver.

Request boiler inspectionTalk to an advisor

About our boiler inspection →

General guidance only, not a substitute for a licensed inspection or emergency services. For any gas odor, carbon monoxide alarm, fire, or trapped occupant, call 911 first.