Pressure Canner Troubleshooting – How To Fix Problems

Pressure canner troubleshooting tips, originally posted by ‘Christine Coburn’ for Modern Survival Blog.

“There is nothing more frustrating when you have worked hard to get a batch of food prepared to can, and then your canner doesn’t work right.”

After 30 years of canning, I have learned several canning “tricks”, all of them the hard way.

To understand what’s causing a problem and how to fix it, you first need to comprehend how each part of the canner works in conjunction with the rest of the components.

My pressure canner is the typical run-of-the-mill canner:

Mine is a Mirro 22, made in 1980. It has been in service full-time for 31 years.

Today’s Mirro pressure canner is one of the most popular:
>> Mirro 22-Quart
(view on Amazon)

Pressure Canner Troubleshooting – Various parts of the pressure canner

First, a quick look at basic parts:

Pot
See the locking lugs all the way around.

Lid

Gasket

Canner Racks
One is always placed on the bottom of the pot under your jars. The other is placed on top of the first level, and then a second level of jars on top of it. This is when you are canning pints or half pints and are doing a second level. You can not stack quart jars. Failure to use these will cause your jars to break in the canner.

Stem

Pressure regulator
This is what regulates the amount of pressure in your pot.

High-pressure relief valve
This is the safety mechanism to keep you from blowing the lid thru your ceiling.

Lid locking mechanism
This is also a safety mechanism to keep the lid from blowing through your ceiling.

Troubleshooting Pressure Canner Problems

A list of various problems and solutions:

The lid will not fit on right

The locking lugs are not properly lined up

Place the lid on top of the canner with the lid handles a little offset from the pot handles. Line up the lugs by sliding them back and forth until they fit together snugly, allowing the lid to slide down. Then, turn the lid until the handles on the pot and the lid align.

If your lid doesn’t slide easily once it has seated on the lugs, then coat the gasket with a small amount of vegetable oil to help the gasket slide on the pot.

Pressure Canner is not building pressure

Turn off your burner and slide the canner to a cool spot to cool down before troubleshooting the problem.

Your pressure canner may not be building pressure because the gasket is not sealing correctly.
– Soak gasket in hot water for 15 minutes.
– If the gasket seems loose on the lid, then you can stretch the gasket by working your way around with both hands, pulling on it.
– Try a coating of vegetable oil.
– Replace gasket (good to have a spare on hand !!)

>> Mirro Pressure Canner Gaskets
(view on Amazon)

>> Presto Canner Gaskets

If your pressure canner won’t build pressure, it may simply be due to insufficient heat.
– Increase heat.
– If you have a canner with wing nut-type clamps, then it is possible one of your clamps is not tight.

New Gasket Won’t Seal

You just bought a new gasket for your Canner, and now it won’t seal, or the gasket only lasts a few uses before it fails again.

Turn your pot over and look at the manufacturing date. You see the 12 80 on mine (See picture below). The Mirro 22qt made before 1983 requires a different gasket than is sold at the hardware store now. You probably have the wrong gasket.

Several sites on the internet sell the older replacements. You can call the manufacturer to confirm which part you need.

Gaskets that are used regularly should last 3-5 years. Usually, what causes them to fail is not using them, and they dry out.

Old faithful erupting on the stove

Steam is pouring out from under the lid. Slide the canner to a cool spot to cool down before troubleshooting the problem.

The lid locking mechanism did not lock
– Try jiggling the lid to get the mechanism to lock. Some canners are very picky about the lid placement and this mechanism.

Food is hung in the lid lock mechanism
– Make sure your lids and jars are clean before processing.
– Check the gasket, under the gasket, and the lid lock mechanism for pieces of food.

Gasket not sealing
– Soak gasket in hot water for 15 minutes
– If the gasket seems loose on the lid, then you can stretch the gasket by working your way around with both hands, pulling on it
– Try a coating of vegetable oil
– Replace gasket if it is dry, hard, cracked, or torn.

If you have a canner with wing nut-type clamps, then it is possible one of your clamps is not tight.

The high-pressure valve just popped

(Hurry and throw a damp rag on top of the valve so that you do not lose your jars, do not get your hand in the way of the steam, it will burn you). Slide the canner to a cool spot to cool down before troubleshooting the problem.

The stem is clogged
– Always make sure your pot and lid are clean before you use them, and make sure your jars are clean when you put them in.

The pressure regulator quit jiggling and is now just blowing a steady stream of steam

Too much pressure in the pot
– Turn down your heat a bit

The pressure regulator quit jiggling and is not blowing steam out

Not enough pressure in the pot
– Turn up your heat a bit

Lids not sealing

Rims are not clean when lids are placed on
– Wipe the rims with a clean, damp cloth before placing your hot lids on them

Pressure is being dropped too fast
– Never drop the pressure artificially. Allow the pot to cool naturally. By dropping the pressure, it creates negative pressure in your pot, which pulls the jar contents out into the pot from under the lids.

Using used metal lids
– Never reuse a metal lid. The only lids suitable for repeated use are Tattler lids with gaskets.

Not enough headspace
– Leave about ¾ of an inch between the top of your food and the top of your jar. The jars will boil in the canner, and if you do not have enough empty space in the jar, then the contents will be pushed out of the jar, causing grease and food to get under the lid.

Rings are not tight on metal lids
– Tighten rings over metal lids prior to processing

Rings are too tight on tattler lids before processing, or are not tightened down after processing.
– Tighten and then back off the rings over a Tattler lid ¼ inch, then tighten the rings after the jars are processed and removed from the canner. Use an oven mitt, the jars are HOT!!!

Today’s Top-Of-The-Line Pressure Canner Brand:
All American on Amazon

Model 910 10.5 qt (7 RM pints or 5 WM pints or 4 RM/WM quarts)
Model 915 15.5 qt (10 RM pints or 8 WM pints or 7 RM/WM quarts)
Model 921 21.5 qt (19 RM pints or 16 WM pints or 7 RM/WM quarts)
Model 925 25.0 qt (19 RM pints or 16 WM pints or 7 RM/WM quarts)
Model 930 30.0 qt (19 RM pints or 16 WM pints or 14 RM/WM quarts)
Model 941 41.5 qt (30 RM pints or 25 WM pints or 20 RM/WM quarts)

Pressure Canning Tips

If at any time you lose pressure in your pot, you must start retiming the food from the time you rebuild the pressure.

Always let the canner vent steam for at least 10 minutes before placing the weight on the stem. This allows the air to escape from the pot and ensures the stem is clear.

Always make sure your canner is clean and the jars are clean before canning, or you can clog your stem. Inspect it before each use.

Always ensure you have sufficient water in the pot to cover the entire processing time. If you let a canner run dry, you will warp the pot and break your jars.

NEVER drop the pressure purposely by removing the weight or running cold water over the pot. Always allow the pot to cool naturally by only sliding it to the cool side of your stove or counter. Failure to do this can cause steam/burn injuries, broken jars, and seal failure.

If you encounter a problem with your canner, gently and carefully slide it to a cool place and then leave it alone until the pressure has subsided. If too much pressure builds, it will make a howling sound from the steam escaping the escape valve or from under the lid. The escaping steam will burn you!!!

 
[ Read: Home Canning Tips And Lessons Learned ]