Steam-jacketed kettles can last as long as 20 years, depending on usage and care. But here are a four signs that it may be time to replace a kettle.

Leaking: If the kettle's compound gauge does not reside in the "green zone" when cool, this could indicate a leak in the unit. Also, look for visible leaking from the kettle's jacket area.

High repair costs: If an older kettle's repair costs start getting too high, it may be time to consider retiring it and purchasing a new one.

Slower cooking: If the unit takes longer to cook, this could be a main indicator that the kettle either has a leak or a failure of the heating element. Both instances indicate a new kettle might be necessary.

Material breakdown: Inner liner pitting and/or external stress fissures, which may occur from heavy use or acidic foods, may indicate the end of a kettle's service life.