This guide explains how an oven operating in ‘Sabbath mode’ can be used to keep food hot for Shabbos.

This page refers to ovens which have a Sabbath mode which have been reviewed but have no hechsher. To be used in a halachically correct way, the following guidelines apply:


In some cases, use of the word ‘Sabbath mode’ is a misnomer as manufacturers do not fully understand the issues and simply want their product to sell!

When manufactured under the certification of a competent halachic authority, an oven working in ‘Sabbath mode’ is truly ‘Shabbos friendly’ as it complies with the laws of Shabbos – allowing one to access food which is heating in the oven, and has been placed there to heat before Shabbos. FedTech have recently certified some models and these are listed by clicking here.

Here in the UK, an increasing number of models offer a Sabbath mode, but some are manufactured without halachic certification; we therefore advise that an oven should only be used on Shabbos if it has a hechsher or it has been reviewed and approved by a halachic authority.

By their own admission, some companies have manufactured ovens which raise halachic concerns even if ‘Sabbath mode’ is operating. Members of the public are advised to contact FedTech to confirm the status of any oven with Sabbath mode.

2. What are the issues when using ‘Sabbath mode’?

The following is a list of potential issues when using ‘Sabbath mode’:

  • Light and fan turn on or off when door opens or closes
  • When oven is operating, element switches off when door is opened
  • Heating element reignites when door closes
  • Writing on LED display screen appears or changes when door is opened

A halachically sound ‘Sabbath mode’ will address all issues by neutralising the effects of opening and closing the oven door on appliance activity.

This mode also addresses issues related to convenience and technical design. Amongst them is an ‘auto cut off’ feature – designed to lower the risk of fires; this safety feature will halt oven activity after a period of time. To allow for the convenience of Yom Tov cooking, the oven continues to run for up to 72 hours, but at a relatively low temperature.

3. Which ovens have been reviewed by FedTech and what are their usage instructions?

FedTech have issued a hechsher for a number of ovens widely available on the market. Other ovens have been researched and approved. These include some ovens manufactured by BSH group (under the brand names Neff Bosch and Siemens). Since these ovens continue to operate the thermostat even in Sabbath mode, opening and closing the oven door may only be done in accordance with halachic guidance.
These ovens carry specific instructions which somewhat limit their usage on Shabbos. The following instructions apply:


  • All food must be fully cooked and in place in the oven before Shabbos
  • NO FOOD whether raw or cooked, hot or cold may be PLACED in the oven on Shabbos
  • The temperature can be set before Shabbos to ANY level (the manufacturers have limited this to below 140 degrees)
  • In ovens which carry an element indicator light (or the user has installed an indicator light), the door should only be opened when the light is ‘on’.
  • An oven which has an indicator light may be opened and closed repeatedly, with the food in situ, when the light indicates that the element is working.
  • In an oven which does NOT feature an element indicator light, food which is left in the oven over Shabbos MAY be removed during Shabbos ONLY ONCE, -but ALL food MUST be removed before the oven door can be closed again.

FedTech can supply an indicator light which has been specially developed for this purpose and can be fitted to your home oven. Click here for information on FedTech’s own indicator light project.

It is important that members of the public contact FedTech before purchasing an oven which will have an indicator light installed.

On Yom Tov, the following applies:

  • The oven should be set to the desired temperature in ‘Sabbath mode’ before Yom Tov.
  • No adjustments may be made to the temperature setting during the course of Yom Tov.
  • Food may be placed in the oven to cook or heat on Yom Tov and need not be in place from before Yom Tov.
  • The door may be opened and closed without limits as required during the course of cooking. It should not be opened for no reason. If an element indicator light is present, it is preferable to open the door only when the indicator light is lit.

4. Is there any permitted way to make use of an oven which has not been reviewed by FedTech?

Please click here for a guide on using an oven without an approved ‘Sabbath mode’ on Shabbos.

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