How To Kosher A Fridge - The Federation of Synagogues

How do I prepare my fridge/freezer for Shabbos?

1. WHAT IS THE PURPOSE OF THIS GUIDE?

This guide has been developed to equip the reader with the information necessary to be able to resolve problems which arise when making use of fridges and freezers on Shabbos and Yom Tov.

2. IS IT SUFFICIENT TO UNSCREW THE LIGHT BULB?

Even if the light bulb in your fridge can be removed, there may be other Shabbos related problems. The following is a list of some of the potential issues:

Light is operated by door opening
Fan is operated by door closure
Alarm sounds if the door is left open
Separate vegetable drawer lights LED screen display changes when the door is opened

The consumer is recommended to look and listen carefully for any of these issues as their presence can easily go undetected. If any of the above are issues, it will be necessary to neutralise the door switch. See below for guidance as how to do this.

3. HOW DO I PREPARE A FRIDGE OR FREEZER FOR SHABBOS USE?

Modern fridges are equipped with at least one door switches. There are two types of door switches:

Traditional plunger switch
Hidden magnetic contact switch

Before Shabbos all such switches need to be neutralised – the device should be tricked into thinking it is always closed. See question 4 for details of how to ‘blind’ the modern magnetic switches.

4. HOW DO I PREPARE THE FRIDGE FOR SHABBOS IF I CANT FIND THE SWITCH?

In the past, most fridges operated a light when the door opened – by means of a visible spring loaded plunger switch which was released when the door opened. This could be taped down so that the bulb would not be lit when the door opened. These traditional switches have largely been phased out and manufacturers have replaced them with invisible magnetic switches. This does not, however, mean that the fridge can not be used on Shabbos. In most cases, the fridge can be tricked into thinking that it is closed by placing a magnet on the fridge casing next to the location of the reed switch. The following steps should be followed to locate the ‘magic spot’ and ensure that the fridge can be used on Shabbos:

The door should be opened so the light is lit.
If the lightbulb has been unscrewed, screw it back in. If the fridge doesn’t have a light, see question 5 for details as to how to neutralise the door switch.
A small, powerful magnet should slowly be moved around the casing of the fridge – click here to be taken to our Recommended Products to purchase such a magnet.
When the light goes out, the magnet is in the correct position and the fridge has been tricked into thinking that the door is closed.
In some fridges the switch is located at the front of the fridge in the centre of the its roof; in others the switch is hidden near to the door’s hinges. Sometimes a fridge can have more than one switch.
The magnet may need to be taped down in the correct position.
It is advisable to draw a line carefully around the magnet once it is correctly placed. This will help if the magnet is moved and will avoid unnecessary struggles to correctly relocate the magnet.
It has been noted that in some cases, even if a magnet is in place, the lights nevertheless flicker momentarily as the door is opened/closed. This would indicate that the magnet has not been accurately placed. The householder should be aware of this possibility, and test the magnet installation by looking carefully into the doorway to assure that the light is off at all times.
It may be worth contacting a shomer Shabbos appliance mechanic whose experience will assure that the magnet is accurately placed. The small fee to attain the peace of mind that one’s appliance is fit for Shabbos use may be a price worth paying.
To order a magnet from us, please click here to see our Recommended Products page.

5. MY FRIDGE DOES NOT HAVE A LIGHT, HOW CAN I TELL WHERE TO PLACE THE MAGNETS?

Even if your fridge does not have a light, there may be other ways to work out how to place the magnet:

In many devices if the door is left open for a few minutes, an alarm will sound. This alarm may be controlled directly by a door switch. Move the magnet carefully around the appliance until the alarm is stopped. Tape the magnet down on the spot which stopped the alarm.
In some devices a quiet hum starts as soon as the door is closed. Check whether this applies for your appliance by listening very carefully as the door is closed. If the humming starts as the door closes, then you should slowly move a magnet around, whilst listening for the same humming sound to start. If you find that the humming does start, you have found the door switch. Tape the magnet on the spot where the humming started.

6. MY FRIDGE ALARM SOUNDS WHEN THE DOOR IS LEFT OPEN FOR TOO LONG – IS THIS AN ISSUE ON SHABBOS?

In many appliances, disabling the door switch will resolve this issue as noted above.

In some appliances, the alarm is not activated by door opening and will not be disabled by door closing; instead, the alarm is sounded when the internal temperature has risen too high. If this is the case, closing the door would not directly deactivate the alarm; rather, the alarm will continue to ring until the desired temperature has been attained. Closing the door is permitted under these circumstances as the interaction with the appliance’s electronic controls is considered indirect.

7. MY FRIDGE MAKES A WHOOSHING NOISE AS SOON AS THE DOOR IS CLOSED – IS THIS A PROBLEM WITH REGARD SHABBOS, WHAT CAN I DO TO RESOLVE THIS?

If you would be describing a quiet humming noise, this would be an indication that the motor or fan are running as the door opens, This issue would need to be resolved by neutralising the door switch. See above for information on how to do this. The whooshing noise, however, is of no significance at all, and experts we have consulted explain that this is just the sound of the air being drawn to the fridge by the vacuum created by the difference in air pressure between inside and outside of the fridge’s cavity.

8. WHAT DO I DO IF I HAVE QUESTIONS ABOUT THIS GUIDE?

Questions on this guide can be sent to technology@federation.org.uk.