How to Clean a Presto 23-Quart Pressure Canner: Seals, Vent, and Gauge

Step-by-step instructions

Step 1: Wait for complete cooling and pressure release

Finish the normal operating sequence and allow the canner to cool and depressurize according to its manual before removing the cover. Never force a cover, defeat its lock, or use cleaning as a reason to open it early. Once completely cool, remove the sealing ring and overpressure plug for washing. Keep track of which piece came from each opening. Inspect for food deposits before taking apart anything else; routine cleaning does not require disassembling the pressure gauge or dismantling every fitting on the cover.

Step 2: Wash the body, rack, and removed rubber parts

Use warm soapy water on the canner body, canning rack, sealing ring, and overpressure plug. Remove residue, rinse, and dry thoroughly. Presto excludes all canner parts from the dishwasher, so even the metal body and rack belong in the hand-washing routine. Avoid striking the body's rim with metal utensils or scraping a sealing edge. Do not pour water into a dry overheated canner to start washing; allow it to cool first. A clean, undamaged rim is more important than removing every cosmetic mark.

Step 3: Keep the dial gauge dry while clearing the vent

Wipe the inside of the cover with a damp cloth and clean the ring groove with a brush as needed. Do not submerge the cover's dial gauge or allow it to become wet. Hold the cover toward a light and look through the vent pipe. If that passage is partly blocked, clear it with a small brush or pipe cleaner and check it again. Do not drill, enlarge, or reshape the opening. A gauge that has been immersed needs an accuracy check, not merely surface drying.

Step 4: Clean the air vent and cover lock when necessary

For the removable lock assembly, hold its cup underneath the cover and turn the upper pin counterclockwise with your fingers. Remove the pin, cup, and small gasket from the cup's threaded shaft. Wash the pieces and brush the cover opening with a small nylon brush. Refit the gasket on the cup shaft, insert the cup from underneath, and screw the upper pin on clockwise until finger-tight. Do not use a wrench: overtightening can wrinkle the gasket. The word TOP must be visible from outside the cover.

Step 5: Refit the sealing ring and overpressure plug correctly

Inspect the rubber for hardness, cracks, deformation, or wear. Presto calls for replacing the sealing ring and overpressure plug at least every three years, sooner if their condition requires it. To remove the plug, push it out from the top of the cover. Reinstall its domed side from underneath until its bottom edge sits evenly against the underside; TOP should show outside. A plug expelled by excess pressure must not be reused. Contact Presto to investigate that event before using the canner again.

Step 6: Distinguish harmless discoloration from damage

Darkening of the aluminum interior can result from water minerals and food interaction, so discoloration alone does not establish that the canner is dirty or unsafe. Presto provides an optional cream-of-tartar treatment and an annual interior-cleaning recommendation in the manual's care section. That treatment involves pressurizing the canner, so read the complete method and limits rather than substituting a casual vinegar boil. Pitting, a nicked rim, a warped base, and persistent steam leakage are different concerns; inspect them instead of trying to polish them away.

Step 7: Dry, store, and arrange the separate gauge check

Dry the parts completely and store the canner above freezing in a dry location, with the cover inverted on the body as directed. Check that the lock parts remain finger-tight and that handles are secure. Arrange a dial-gauge accuracy check before each canning season and after events such as a dropped or submerged cover, rust, or a pointer that does not rest in its zero block. The 0178107 manual page links the applicable instructions. Do not operate a canner with unresolved leakage or an uncertain gauge.