Getting Into Hot Water: Urns & Pump Pots in Halacha – Shabbos & Yom Tov

Spring 2020

Electric urns greatly enhance our oneg Shabbos and Yom Tov by allowing us to effortlessly enjoy hot drinks. However, the technological advances that permit us to use urns on demand come along with a host of halachic considerations that must be carefully reviewed.1

A summary of the various halachic considerations in the usage of electric urns, pump pots and commercial urns are addressed in this article. An urn is a heater that lets the water out through gravity using a lever at the bottom of the urn. A pump pot uses a pump at the top to force the water out. In this article, the term urn is used generically to refer to a pump pot, as well (except as noted in the section about the water level tube).

Keep in mind that there are many different types of devices, and not every situation is applicable to all of them.

Heating, Adding and Dispensing

Heating: It is best to bring the water in the urn to a complete boil before Shabbos.2

Adding: Adding water on Shabbos is always prohibited. On Yom Tov, it is permitted to add cold water provided no light goes on or off immediately upon adding the water, and the heating mechanism does not immediately turn on.3 Before Yom Tov, one can test to see how much water can be added before activating the urn. To test, follow the steps in the footnote.4

Dispensing: It goes without saying that dispensing water is permitted through mechanical means only (i.e., the use of spigots or levers). One should not press any electronic buttons.

Shabbos Mode/Yom Tov Mode

Some urns feature a Shabbos Mode”. On some models, this mode only disables the electronic buttons. For example, some models have a button which allows dispensing from a pump pot without having to manually ‘pump’. The Shabbos Mode” disables that button. However, even without disabling that button, one could simply opt to use the manual pump.

Yom Tov Mode” is a feature available on some urns and is obviously for Yom Tov use only. When this feature is engaged, the urn supposedly allows the user to refill the urn with cold water without activating any mechanisms. When STAR-K tested some models, we found that the mode only disabled the lights and buttons but not the reboil, which was activated as soon as cold water was added.

You should make sure that the Shabbos or Yom Tov mode feature is reliably certified and works as intended by testing it before Shabbos or Yom Tov.5

Covering the Urn

Sometimes, users want to cover the urn with a blanket or cloth to maintain the temperature of the water during Shabbos. Placing a covering that fully covers the urn is prohibited, even on Erev Shabbos and certainly on Shabbos.6 If part of the urn is left uncovered, then it would be permitted– even on Shabbos itself.7 There are no restrictions on Yom Tov with respect to covering the unit.

Tilting an Urn

On both Shabbos and Yom Tov, one should not dispense water from an urn if it is beneath the level of the spout (by tilting it). Doing so creates a halachic concern that one may be tempted to unplug the urn or add water to avoid damaging the urn.8 (Aside from halachic issues, removing the water is not advised since the element may overheat and should not be done, even on a weekday, unless the urn is first unplugged.)

Water Level Tube

Many urns include a tube of water on the outside of the tank that displays the level of the water inside the urn. When the urn fills up, the tube fills to the same level. When water is removed, some water from the tube flows out and is cooked by mixing with the water coming from the urn. There is concern that the water in the tube has not been cooked and, if so, removing water from the urn would be forbidden on Shabbos (but permitted on Yom Tov).9

Determining if the water in the tube has been heated is definitely a challenge. Some tubes feel very hot while others do not, especially at its top. The tubes generally do not allow easy access to thermometers or other temperature devices.

Some experts with whom we consulted thought that since there is some connection to the water in the pot, and it is being heated, the water will quickly move from the tube to the urn and then back again. In this way, all the water in the tube has been cooked in a short amount of time. Others argued that the water will not mix so quickly.

STAR-K consulted with engineers and undertook the testing of urns to see if the water moves from the tank into the tube, and the amount of time it would take to do so. Different models of urns were heated, then a food dye was poured into the urns.10 In all cases, the dye began flowing into the tube almost immediately. After a very short time, the tube was the same color as the water in the urn. This indicates that there is an exchange of hot water into the tube.11

Even if the water in the tube does not remain boiling hot (especially at the top of the tube), the Rama12 holds that water which has once been heated and has not totally cooled down is no longer subject to restrictions upon further heating.

Based on this finding, Rav Moshe Heinemann shlit”a has paskened that one can use the urns without concern for the water in the tube.13

If one still wants to be strict about this issue, there are several options:

  • There is usually a visible hole on the top of the tube that allows air to enter. If that is covered with tape before Shabbos, no air can get in and the water level will not change in the tube. (On some tubes, this hole is not accessible.)
  • Alternatively, you can put tape over that hole before filling the urn on Erev Shabbos, then permit the water to boil and remove the tape to allow the boiled water to flow into the tube.
  • Some urns work in the following manner: When the lever is pressed to remove some water, the level of the tube is significantly reduced. When the lever is released, the tube refills with boiled water from the urn. Therefore, after the water has boiled on Erev Shabbos, and the lever is pressed a few times, one can be certain the tube is full of boiled water. (Other urns work differently. The tube level goes down only slightly when water is removed. This would not be a solution for those urns.)
  • Boil the water on the stovetop and pour it into the urn before Shabbos. (Some would not consider this a practical solution because the point of having an urn is to avoid this!)
  • Unscrew the tube and block the water flow into the tube at the bottom. This method requires some expertise or special tools.
  • Opt for an old-style type of urn (e.g., West Bend Coffee Urn) that doesn’t have a tube. (An advantage of this brand is that it is UL-listed as safe, while many urns on the market are not UL-listed. Always check appliances for the UL marking or equivalent [e.g., ETL]).

Large commercial urns with automatic refill were not tested and one should employ one of the above solutions. However, they often run at a high temperature. One can feel the tube at the bottom, and if one’s hand cannot be held there for 15 seconds then the water in the tube is being heated.14

A pump pot works differently than an urn. Dispensing water from a pump pot involves pushing down on a pump mechanism located at the top of the urn. Pressing this mechanism pushes the water up through the tube and out the top of the pot. In the previously mentioned dye test, the dye was not transferred into the pump pot tube due to the different setup. Therefore, this poses a potential issue of bishul by mixing hot water in the pot with the water in the tube which may not have been sufficiently heated. However, with pump pots the solution is easy. After boiling the water before Shabbos, pump a few ounces of water out of the pot. This will push out the water from the tube, and the tube will then be filled with boiled water from the pump pot.15

Does Removing Water Cause the Urn to Activate?

This is another question we are asked regarding the use of urns on Shabbos. The argument made by some poskim is that the removal of hot water causes cold air to enter the urn, causing the urn to activate, which is prohibited.16

STAR-K tested various urns with a meter that measures total usage of power, as well as a Fluke brand tester17 that measures power usage per second and records the information.

None of our tests showed that the heating element was using more power or was activated sooner, although for technical reasons these tests could not be considered 100% conclusive.18 Since it is very difficult to ascertain, and one does not intend to cause an increase in power when removing water, halachically one is not obligated to be concerned about this on Shabbos. Therefore, one may dispense water from an urn on Shabbos without worrying that he is activating the urn by allowing cold air to enter.19

Automatic Refilling of Commercial Urns

Commercial urns in shuls, yeshivos and hotels are often connected to piping and automatically refill when water is taken out. The urns generally have a water level sensor near the top of the inside of the urn.20 To allow use on Shabbos, shut off the water input and do one of the following:

  1. Remove enough water from the urn before Shabbos to bring the water level below the sensor. Removing a few cups of water should be sufficient, but this should be tested on each urn.
  2. Install a switch to bypass that sensor and activate it before Shabbos.

On Yom Tov, the urn may be used even if it refills. However, if there is a sensor then one of the above solutions is still required.

Instant Hot

An “instant hot” device attaches to a sink and is connected to a small tank of water under the sink. The tank keeps the water at a high temperature and is refilled automatically through its connection to the water supply. The tank refills as the chamber empties and then boils the water as needed. Use of an instant hot device is always forbidden on Shabbos.

If the heating element is not activated immediately, one can remove water on Yom Tov. To determine permissibility on Yom Tov, we tested a popular model which holds 2/3 of a gallon. Our testing showed that one can assume the device is not immediately activated after removing one cup of water.21 After allowing sufficient time for the water to boil, one could take another cup.22 If the tank would be significantly smaller, it is possible that taking even one cup would be forbidden, and such a device should be tested before use.23

Due to advances in technology, there are more and more options that provide us with hot water on Shabbos and Yom Tov. Knowing the halachos allows us to enjoy our hot drinks in a permissible way.

The author would like to thank Mr. Jonah Ottensoser, STAR-K engineering consultant, for his assistance with this research.

  1. See “Getting Into Hot Water (Part One, Tevilah and Workplace)” and “Getting A Handle On Your Faucet” by this author at See also “Instant Foods In The Kosher Home” by Rabbi Avrohom Mushell.
  2. Shmiras Shabbos Kehilchasa 1:63. However, if the urn has no means of changing the temperature one can fill it with cold water before Shabbos even though it will boil on Shabbos, since it is considered “grufa u’ketuma” (Rav Moshe Heinemann shlit”a). In such a case, water may not be removed before the boiling is complete as this will speed up the boiling process and is considered bishul. (See Meor HaShabbos 1:pg 516 quoting Rav Shlomo Zalman Auerbach.)
  3. Grama, an indirect action (a delay of 5 seconds or more), on hav’arah is permitted on Yom Tov (Shaar Hatziyun 514:31).
  4. To test, follow these steps: (A) Boil some water in the urn. (B) Slowly add cold water and listen for the ‘click’ that indicates the urn is beginning to boil the added water. (C) The amount of water that can be added on Yom Tov is less than the amount that activated the urn. For example, if three cups of water activated the urn, only less than three cups could be added on Yom Tov. (The amount you can add without activating the urn will also depend upon the amount of water remaining in the urn. If there is little water left, the urn will likely turn on faster.)
    A work-around on Yom Tov is to add hot water that was heated in a stovetop kettle. (The purpose of doing this would be to have hot water conveniently available for later in the day.) This should not cause any change.
  5. As stated above, on Shabbos it is always forbidden to add water.
  6. The heating element and cover cause this to be hatmona b’davar hamosif hevel, covering with something that adds heat, which is prohibited on Shabbos. (Shulchan Aruch O.C. 257:1, Mishnah Brurah 253:69).
  7. The amount left uncovered should not be minuscule; it should be enough to make a difference in the heat retention.
  8. See Mishnah Brurah 318:118 , Orchos Shabbos 1:pg75, and Shemiras Shabbos Kehilchasa 1:40. Modern urns usually have a cutoff which will sense overheating, but the urn may still be damaged in the process, Additionally, one is not permitted to trip the cutoff.
  9. Poskim debate how hot the water needs to get to be considered cooked.  Is it enough to be yad soledes bo or must it be fully boiled?  Rav Elyashiv zt”l has been quoted as ruling strictly (Oztros HaShabbos pg 528).  He was concerned that even though the water in the tube was heated, it would mix with the water in the pot and be raised from yad soledes bo to boiling. (However, Shalmei Yehuda 2:14 quotes Rav Elyashiv as not being concerned about the water in the tube.) On the other hand, many poskim are lenient on this question and hold that as long as water was heated to yad soledes bo it is considered cooked. For example, see sources quoted in Minchas Yitzchak 10:28, and Nishmas Shabbos 4:1. Rav Shlomo Zalman Auerbach (Otzros HaShabbos pg 529) is quoted as permitting the use of an urn with a tube. He was told that the water in the tube had been cooked. See also Nishmas Shabbos 1:9.
  10. If doing this at home, be careful with the dye as it stains clothes and countertops.
  11. We repeated the test with cold water and found there was little transfer of the dye through the cold water. This further indicates that heating causes the transfer of the dye and water.
  12. O.C. 318:15
  13. Sefardim follow the Mechaber (O.C. 318:4), who states that water that has cooled below yad soledes bo and is reheated is considered bishul; this seemingly would be a concern here. However, Rav Ovadiah Yosef (Yechaveh Daas 6:21) is lenient on the reheating of the water in the urn tube for various reasons, including that it is a psik reisha d’lo nicha leh, since he doesn’t care whether or not the few drops in the tube that come out are heated. Rav Ben Zion Abba Shaul (Ohr l’Tzion 2:30: note 10) is also lenient.
  14. See also the section in this article regarding the automatic refill of commercial urns.
  15. This solution is also discussed by Rav Yisroel Belsky in Shulchan Halevi, pg 55. Alternatively, before Shabbos one can pump out a few drops of water (which will come from the tube) to see if they are yad soledes bo (120°F ).
  16. On Shabbos, this would be forbidden due to the grama of hav’arah, kindling the heating coils. On Yom Tov, this would not be a concern.
  17. A high-end testing device (listed at $5000).
  18. We were able to conclude definitively that the West Bend Coffee 30- cup urn, due to its simplicity, did not cause any changes when water was taken out.
  19. Rav Shlomo Zalman Auerbach is quoted as having ruled leniently. It can be assumed that it is not a psik reisha or, at most, it is a sofek psik reisha and a grama (Me’or Ha’Shabbos 1:pg 509). See, however, Orchos Shabbos 1: pp 73-74, who rules strictly on this issue.
  20. The concern is that whenever the water level drops below the sensor, a valve is activated and opens to allow water into the urn. Turning off the water intake is not enough to allow use of the urn, since at some point someone who takes out water on Shabbos will still trip the electromechanical valve to open; this is forbidden. Please note that older urns may use a mechanical float and would not cause any valves to open.
  21. Depending upon the device’s position in its cycle, even one cup may activate the element. However, at most this is a sofek psik reisha on a d’rabonon and is therefore permitted. (See Be’ur Halacha O.C. 316 v’lachen).
  22. There are many variables that determine how soon another cup could be taken. One could test his own device to assess. After 15 minutes, one can definitely assume another cup is permitted.
  23. To test, follow these steps: (A) Use a power usage meter that measures how many amps are being drawn. These are inexpensive, less than $20. (B) There will be a power outlet under the sink that powers the instant hot. Plug the power cord of the instant hot into the meter and then plug the meter into the outlet. (C) Set the meter to read amps. When no power is being drawn, it will read ‘0’. Have someone push the lever of the instant hot, and count how many cups are taken out, before the meter shows that amps are being drawn. (D) Wait till the water boils and repeat the test a few times. If you can remove a few cups before the power is drawn, then you can assume that one cup will not activate the device.