February 9, 2014 at 6:20 pm #612094
Having had some discussions with my sons about this topic,there are surprising conclusions on this. Generally accepted is that you cannot use water from a hot water tank on shabbos. Yet, there may be reasons to be “mattir” this. What is the minhag of the “coffee room” participants?
February 9, 2014 at 6:39 pm #1002837
“Yet, there may be reasons to be “mattir” this. “
Reasons? What reasons that be, and which posek said such reasons exist?
February 9, 2014 at 6:43 pm #1002838
It would be muttar al y’dei aku”m, though.
February 9, 2014 at 8:47 pm #1002839
WIY (and DaasYochid): my very erudite sone pointed me to a teshuvoh by R’Dovid Kronglass zz’l (after the war, mashgiach at Ner Yisroel) in his sefer “Divrei Dovid’ (last teshuvo,number 87) where he discusses this in unusual terms, asserting that, in hilchos shabbos, “gromo’ is muttor. I paraphrase a teshuvo of SEVEN long pages- you can find it in hebrewbooks.org. I will try to quote some of his highlights later.
February 9, 2014 at 9:16 pm #1002840
Can you please post a link?
February 9, 2014 at 9:38 pm #1002841
I’ll bli neder look a little later (I found it: http://hebrewbooks.org/pdfpager.aspx?req=40815&st=&pgnum=316&hilite=), but R’Moshe doesn’t see a tzad heter.
February 9, 2014 at 9:55 pm #1002842
So here’s a question… Is there such a thing as a tank that ONLY allows the cold water to come in if the hot water level dips to a specific low? So if someone were to use less than that maximum amount, it would NOT cause cold water to enter the tank and be cooked on Shabbos?
February 9, 2014 at 10:23 pm #1002843
oomis: in such a case it would be okay if the water boiler never went to 110 at all during shabbos not just when the water is going in. i heard of someone who rigged his system exactly as you describe.
DY, Berlin, etc: grommo is ussur mdirabunun. many great talmidei chachumim matired electricity use on shabbos and yuntiff. the olam didnt agree (and the tzad hetr was based on faulty science in any event).
February 9, 2014 at 10:27 pm #1002844
DaasYochid; I am embarassed to say but I do not know how “to post a link”. Also, the actual teshuvo starts earlier than your posted link. (starts on page 301- shin-alef)
I am aware that the vast majority of Poskim do not allow it ,as I said in my initial posting, but R’Dovid zz’l has a novel way of looking at it-‘midin gromo’-that brings with it many other facets and may have applications in different situations.
oomis- I do not know to answer your question but I would not be surprised if such mechanism exists, in today’s technologically rich world. And, most interestingly, if such mechanism exists, the issues raised by the teshuvo I mentioned become even more relevant.
February 10, 2014 at 12:24 am #1002845
ROB: One has to ascertain that the Rov issuing the Psak to be lenient was/is FULLY knowledgeable with the ENTIRE mechanism of the device / apparatus / appliance. I don’t C”V want to belittle any Rov’s kavod, but it was known to occur in the past. Unknowledgeable technicians “experts” presented and explained different machines to Rabbonim, Gedolim in the wrong way. Totally. (I used to be very scientifically inclined, when I read certain seforim “A certain expert explained it to me…”, I had a hearty laugh)
There is a world of a difference between a frig, air conditioner and the likes where one may be gorem an earlier on or off (according to most / some). Even the water system pumps that will definitely be working due to one’s use, is also permitted. Too much lumdus – not for me.
But saying a hot water heater is a gorem is pulling it a bit too far. – The only way hot water is shooting out at the faucet, is because cold water is entering and pushing it out. Not a gorem at all (issur occurs at and by the motion of the faucet). Not even a she’aino miskaven – you do want it! If you turn off the cold water, your not going to get anything.
The only mechanism that should exist today, should be an air-pressured force going into the cold line feed, with the cold turned completely off before Shabbos.
I don’t know why nobody thought of it. (if people come out with such a device, KNOW – they got it from Little Froggie, on the Yeshiva World!!)
February 10, 2014 at 1:52 am #1002846
Little froggie (and besalel): with the greatest respect to your postings, you have not read the teshuvo (which runs over ten pages) and which ,by the way, shows the gadlus in torah of R”Dovid Kornglass zz’l. Go, read it, try to understand it and you will see that he deals with every one of your points, including the fact of “gromo” which, btw, is muttor on shabbos. Please go read the teshuvo! (BTW- it is not “miskaven”- you do not want the incoming water to be heated)
I am not saying that you should pasken like this but it is rather presumptuous to reject a view before reading the teshuvo!
February 10, 2014 at 2:03 am #1002847
I have heard of people leaving a faucet running with a tiny trickle of hot water to allow normal usage on Shabbos, but I don’t like that loophole, you are still causing more cold water to heat up as soon as you turn on your faucets.
February 10, 2014 at 2:11 am #1002848
Whoever is modding this thread has a tankless job.
February 10, 2014 at 2:29 am #1002849
Of course someone omitted to mention that in the first paragraph R D. Kronglass specifically says that he is not writing this ????? rather just ????? ??????.
February 10, 2014 at 3:15 am #1002850
nisht: I did say that most Poskim do not pasken like that. And, although R’Dovid zz’l does say that this is for Poskim to conclude, if you read the whole teshuvo, it is evident that he absolutely believes in his conclusions. He does not spend ten pages of mareh mekomos from “ganz shas” and Poskim just for the fun of it.
February 10, 2014 at 3:52 am #1002851
Gramma is actualy not Muttar on Shabbos. Perhaps you mean a Gramma She’ein Mis’chaven.
February 10, 2014 at 3:52 am #1002852
I don’t think he feels the ????? ?????? is just for fun of it. That is just a silly comment.
And from what I read on my phone, he says that it would be ossur. Perhaps it would be mutar to use the water if the spout was turned on. Bit not that it was mutar to open the spout ???????.
February 10, 2014 at 4:03 am #1002853
ROB, I spoke to a competent Halachahist (Rabbi), he told me you’re absolutely correct. While that’s not the general p’sak, he understood and took into account its design and mechanism, how it works, and deemed it to be a geramah.
(I knew I shouldn’t hop in where I don’t belong)
February 10, 2014 at 3:10 pm #1002854
HaLeivi: if you can, get hold of the teshuvo. R”dovid zz’l
deals withb all the details and minutiae of this matter and covers a multitude of rishonim and acharonim.
Little Froggie : Thank you . At times, I fight an uphill battle in the coffee room, so it is comforting to know that I am not totally stupid.
February 10, 2014 at 3:39 pm #1002855
I will not attempt a halachic opinion. But I will mention that we sometimes turn off the “breaker” on our electic panel – the one that is for the hot water heater only.
The water is then warmish, depending on the season winter or summer and can be used for washing hands or dishes more pleasantly than the icy water from the cold water faucet in the winter.
Some might say the warm is very hot Friday night and might be a cooking question as well, when water enters the tank. If many take showers close to Shabbos, this will make the water only lukewarm when Shabbos starts.
February 10, 2014 at 4:14 pm #1002856
The cold water getting cooked indirectly is also “Lo neecha lo”
In addition to turning off the themostat, shut off the cold water intake of the water boiler tank to resolve the bishul issue.
Rav Ruderman zt’l, the Rosh yeshiva of Ner Yisroel did not generally paskin but would refer shailos to Reb Dovid Kronglass zt’l.
truthsharer1 – “I have heard of people leaving a faucet running with a tiny trickle of hot water to allow normal usage on Shabbos, but I don’t like that loophole, you are still causing more cold water to heat up as soon as you turn on your faucets.”
Rav Nachman Bulman zt’l had the hot water going over Shabbos as per your post.
February 10, 2014 at 4:43 pm #1002857
although you did make clear you were not writing saying it is lehalacha and you said ypu know most poskim don’t hold like this i would like to mention R’ Ribbiat (i think it is him i dont want to misquote him) that even if the pilot is off it is still assur since the water in the tank is still yad soledes and you are making cold water come in
even if it is grama it is a a psil reisha which at least by ashkenazim is assur unless done through a derabanon so maybe you could do it with a shinui…
February 10, 2014 at 5:15 pm #1002858
nisht: Actually, I am comforted that the initial posting has engendered some promising discussion -even ,as you say ,it is “le’orer ulepalpel”. I don’t know whether R”Dovid zz’l actually followed his own hetterim (I am sure he was very respectful of the major Poskim like R’Moshe zz’l)but I was floored at the “lomdus” and the vast amount of rishonim and acharonim that he quotes in the teshuvo. R”Dovid Kornglass zz’l was known as the mashgiach- he was much more than that! A true godol! I regret not having known him.
nem621 and kollel-wife- if the pilot light is off, the water will quickly cool down to a point of not being “jad soledes bo”. In normal circumstances, when the water temperature drops to a certain point, it brings the heat back on.
Also, if you can, look at the teshuva. R’Dovid zz’l deals with all the matters that you mentioned,such as “psik reishe’.”gromo”, ‘ein miskaven’ and more.
February 10, 2014 at 6:24 pm #1002859
rabbiorberlin – if not a lot of showers were taken, we used to be machmir not to use the hot water Friday night especially in the summer as it seemed quite hot.
February 10, 2014 at 7:15 pm #1002860
kollel-wife: thanks for your observation. I don’t know whether the cold water entering the system will ever get to “jad soledes bo” if the actual heating was turned off and we enter here in the machlokes whether “ilo-oh govar’ or “taso-oh govar” .The fact that the water you are using is very hot means little. it is what happens to the water that enters the system from the cold water source that is important. On that, I do not know what the actual “metzios’ (reality) is.
February 10, 2014 at 8:48 pm #1002861
when i read this part of a tshuve i thought of this thread and this forum in general.
,??? ????? ???? ??? ???? ????? ?????? ?? ????? ,????? ?? ?? ????? ?? ?? ?? ???? ???? ??????, ???? ???? ??? ????? ,?? ????? ??? ?? ????? ,?????? (-????”? ??? ?”? ?????) ????? ?????? ????? ?? ???? .?????? -?? ??? ???? ????? ???? ??? ????? ??? ???? ???????? ,????? ?????? ???’ ,????? ,?? ?????? ??? ?? ???? ????? ?????[ ,???? ??? ???? ???? ????”? ??????????? ???????? ,????? ????? ??’ ??? ??? ,??????”? ??’ ??? ,???’ ????? ??? (?? ?”? ???-???) ,?”?] ,?? ???-??? ???? ?????? ???? ????? ??????? ??”? ??? ???? ,????? ?????? ,??? ??? ???? ???? ?????? ???????? ,?”???? ?????” ,??”?????? ???”? ?? ?? ????” ,?????? ,??? ??? ???? ????? ?”? ??”? ?????? ????? ????? ?? ?????? ?????? ,????? ???? ????? ?? ?? ??????? ??? ?? ?????? -????? ?? ??”?[ .???? ?? ?? ????? (?”? ?????) -?????? ???????? (??”? ?????) ??? ???? -???? ??? ???? ,????? ,?????? ???? ?????? ????? ??? ,???? ??? (??”?) ?”???????” ????? ?????? ????? ????? ????]. ?????? ?? ????? ???? ?????? ???? ??? ??????? ????? ?? ???
February 10, 2014 at 9:10 pm #1002862
Rav Dovid Kronglass wasn’t the typical Mashgiach at least not like the mashgiach that you think of today. Google about him. He was one of the gedolei hador.
February 10, 2014 at 10:06 pm #1002863
WIY: thanks for the note. You are not only right in what you are saying but it was a revelation to read his teshuvus- they are unbelievable broad and he literally is familiar with all shaalos uteshovos of recent vintage-including many obscure ones. His understanding and “amkus” in the gemoro and rishonim is breath taking.
February 11, 2014 at 1:20 am #1002864
Whoever is modding this thread has a tankless job. “
February 11, 2014 at 1:33 am #1002865
As with Reb Moshe, Rabbi Kronglass soared beyond the title of Rav and in his lifetime was addressed and was known as Rebbe to his talmidim and simply as Reb Dovid to others.
February 11, 2014 at 1:49 am #1002866
ROB: Not sure I agree with you that it isn’t miskaven. After all, he wants to have hot water later too.
February 11, 2014 at 2:08 am #1002867
ItcheSrulik: as most things, this is debatable and may hinge on whether a psik reisha de lo nivhe lei is indeed “lo niche lei” or “lo ichpas lei” (loshon of rashi in shabbos). Maybe he could use the warm water later but he may not care much about it. After all, there are 40 gallons of water in a tank- more than enough for washing dishes and hands, and mayb even a shower or two. AGAIN , please don’t take the above discusssion as halacha- most Poskim forbid using the hot water when it brings in the cold water. I am just interpreting the other “tsad”.
February 11, 2014 at 2:44 am #1002868
from Long IslandMember
When we had a new hot water boiler installed, we had a cut-off valve put in the pipe that feed cold water into the tank. Before Shabbos, we turn off the valve, cutting off the cold water feed. We then use the hot water remaining in the tank until it runs out (usually by Shabbos afternoon – fyi we do not take showers on Shabbos)
It sure makes washing ourselves and the serving platters more pleasant !!
February 11, 2014 at 4:40 am #1002869
How do you get the hot water out? Are you absolutely certain cold water isn’t entering, forcing out the hot? It doesn’t make sense to me, unless the heater is above your apartment – and you allow air in somehow. You should really check it out.
February 11, 2014 at 6:45 am #1002870
Maybe it has a piston.
Wanting the water to be hot later makes it Nicha but not necessarily Miskaven. However, often one causes the other, as per Tosafos 41b.
February 11, 2014 at 12:05 pm #1002871
In Yalkut Yosef there is a long discussion of using the hot water from the typical Israeli setup, a roof top tank with a solar collector. He covers all the halachic bases, and is mattir.
February 11, 2014 at 12:39 pm #1002872
from Long IslandMember
Re; Little Froggie
I honestly do not know how it works. FYI the hot water heater is in the basement of our house.
I just remember that we asked our Rov, and he told us which boiler to buy (I don’t remember his specific reasoning) or how the boiler circulates the hot water. I seem to remember that it works with pressure (from the sinks). I do know that the boiler does not turn on all Shabbos, without the incoming cold water, it does not turn on at all.
February 11, 2014 at 2:04 pm #1002873
In E.Y. they have solar water boilers that can be used on shabbat if set up properly see Shmirat Shabbat Ke Hilcoto -Noibert
February 11, 2014 at 5:01 pm #1002874
to my friend from Long Island:
I think you should find out how exactly you’re getting hot water out of the tank, if it’s not being forced out by any water entering. Of course it works with pressure. Everything works with pressure (I wouldn’t get up in the morning without pressure. I’d be forever hocking away here if not for pressure) There is no “pressure from the sinks” pulling out hot water. Something is pushing it out of the boiler in the basement, all the way up to your sink.
February 11, 2014 at 6:21 pm #1002875
Little Froggie: If you remember your physics class in high school, you’d realize that water always tries to find its equilibrium. The water in the tank will automatically run out of the tank,without any kind of pistons or pressure. As long as the inlet of the cold water is shut (as the posters indicated), all you have is the hot water running out of the tank. Nothing else and with no problem whatsoever in halacha.
February 11, 2014 at 8:47 pm #1002876
Okay, I admit, I never went through high school (gasp), I even started late (double gasp), was home schooled for first grade (wrote about that somewhere else – for those stalking me out here). So I never learned physics, advanced reading, writing, computer skills etc. Some things however I picked up myself, hands-on. (I am writing – and it’s on a computer.)
Now, kindly explain to me and our audience how water in a tank in the basement is “automatically” going to travel upwards to the sinks, without any pressure. (I may be extremely unlearned, ignorant in areas of Torah, Talmud, Halachah and Hashkafah, in regard to earthly matters I pretty much have a hang of matters)
February 11, 2014 at 8:51 pm #1002877
In the US almost always the hot water heater is on the lowest level of the house, thus there would be no way for the water to go anywhere if the inlet was closed.
Perhaps you can do the same that you say you did with strawberries and try it.
Turn off the intake valve for your hot water heater and then see if you get water from your hot water tap.
February 11, 2014 at 8:52 pm #1002878
Little froggie: You can handle a computer so just google- “water fasinds its own level-physics” and it will give you some idea why water comes out of a faucet without any pumps.
February 11, 2014 at 10:17 pm #1002879
nisht (and froggie); please google “hot water expansion tank’ and you will see how tanks work.No pistons, no pumps, just air pressure.
February 11, 2014 at 10:36 pm #1002880
You are actually disproving yourself. Since water seeks equilibrium, how can it flow upwards to a level higher than the water tank? Remember the inlet is shut, equilibrium begins at most at that level. (assuming it does not have fight a vacuum that is created in the tank)
February 11, 2014 at 11:41 pm #1002881
So now you are changing your reason? Do you have an expansion tank? I don’t. Most houses do not. That is only if there is a pressure regulator preventing normal expansion. It is a seperate tank. And that would only allow for a very small amount if water to flow.
February 12, 2014 at 12:07 am #1002882
ROB, but on its way to the sink it would change its mind and remember that really it wants to go back to the tank. It would probably figure all this out before starting out and stay right where it is.
February 12, 2014 at 3:11 am #1002883
Nisht, HaLeiVi: That’s exactly what I was getting at. Which was why I wanted my friend from Long Island to ascertain he has a system which is permitted.
February 12, 2014 at 4:05 am #1002884
I couldnt find the rabbi ribiat so it probably wasnt him
February 12, 2014 at 4:35 am #1002885
Nisht and haleivi: you can google “how does a hot water tank work” ad it will show very clearly how the vast majority of such tanks work. No pistons,no pumps,just water pressure. Btw cold water is at the bottom. Check it out.
February 12, 2014 at 11:45 am #1002886
You keep suggesting a lot of googling and you keep changing your reasons… why don’t you just turn off the inlet valve to your hot water heater and see what happens.
So far, none of your “fargoogeledta” sevaras are logical.
SO cold water goes in the bottom of a hot water tank? That does not explain how, when seeking equilibrium, water will suddenly defy that law and the laws of gravity.
February 12, 2014 at 1:23 pm #1002887
Which is it, water pressue or air pressue? I don’t use hot seltzer so I imagine it is water pressure. ROB, you seem to be missing something very essential here. Water pressure means that there is a load of cold water waiting to enter the tank, but can’t because it is full. When I open my hot water valve, hereby releasing some hot water from the tank, that allows in new cold water, which is what pushes out the hot water.
This is the same pressure that drives my cold water up the pipe. If I shut my cold water in the basement, the remaining water in the pipes will not go up because nothing is pushing it anymore. The same goes for hot water.
February 12, 2014 at 2:33 pm #1002888
Nisht and haleivi, am not sure whether my response was sent. Neither you or I are heating engineers. Google is a great source for information. Use it!
February 12, 2014 at 5:02 pm #1002889
ROB: But I am. And I understand how water moves. And I understand that as long as there is nothing to push out the water (maybe steam buildup pressure, from the trapped hot water), nothing, not even wishful thinking, will get the water out. And certainly not to drive it one floor high. I engineered (ran engines) long before Google came into existence.
February 12, 2014 at 5:44 pm #1002890
ROB, you don’t know what I know but I do know what you don’t.
February 12, 2014 at 6:05 pm #1002891
froggie, Haleivi and nisht: I know-FOR A FACT- that many people who shut off the cold water valve before shabbos STILL get their hot water from the tank! (see also earlier posters). froggie, this has nothing to do with the cold water pushing the hot water out. Water will try to find its level,based on the source of water from far away- simple physics! talk to a professor of physics or a real engineer- you may get the right answers!
February 12, 2014 at 7:06 pm #1002892
Last try. OK? I spoke to an engineer (myself). OK? Please. Unless you don’t believe in science (another thread). Kindly. Tune in to this earthly world.
If you shut off the intake (cold water) NOTHING WILL EXIT – that is your “source of water from far away”. Unless you have air pressure, or hot line pump. Nothing. Again as I wrote earlier, not even wishful thinking will do it. (Maybe with a Shem – if you’re into those things)
Unless you are talking about a boiler on the same level or higher than the faucet – then of course one will have water equivalent to the level of the faucet.
Sometimes one may find some hot water still exists, thats a run from higher elevated lines, which will very soon cease. Or if you have a cross linked faucet, and open both, that’s cold water.
‘Know what? Why don’t you try it. Shut off (completely, no cheating) your cold intake. Open kitchen faucet (hot). See how long it takes to empty existing hot water from higher elevated lines. Then stand and wish for hot water to come. Wish harder, five minutes. Post results. (turn back on cold water, it could burn or bust if you don’t have proper preventive mechanisms)
February 12, 2014 at 7:29 pm #1002893
froggie: will consult engineers. In this cold weather, am not going to turn off water for fear of burst pipes.
February 12, 2014 at 7:35 pm #1002894
Oi vei, the rebbe is silent and the talmidim bicker. ROB, laws of physics are not to be denied, but they work best when you don’t confuse them.
In a typical tank water heater or in boiler coil, if the inlet is shut, there can be no outfow without drawing a vaccum.
Water finding its level is a concept in an open system, not in a pressurized, closed system.
Fixed volume rigid system in which water is heated must have expansion capacity. Hot water heating boilers typically have an expansion tank. A take can only expel what it took in, and these generally have nothing to do with the domestic hot water.
In a heated tank, the hottest water will accumulate at the top. If the burner or element is off, and cold water enters at the bottom, and stays there until a thermal drift cycle mixes it in to the hot. This can’t be seen and not well predicted and thus not relevant.
The ONLY WAY to use hot water from a basement tank is to
A)have the tank below yad soledes and use in a normal manner with the heating element or burner OFF. A limited supply of lukewarm water.
B) To attach an alternate pressure source, that wont be mevushal, such as air pressure vessel, or air compressor loaded, but shut off. The air entering the tank will drive the hot water out, instead of the cold water (with cold vavle off)
C) to have a gravity flow system, with the tank above the point of use (Kithcen) and a vaccum relief to let air into the tank as the hot water exits. This does not work too well if the hot outlet of the tank is at the top, as in an American type water heater. IOW, this need to be purpose-built by someone who knows what he/she is doing.
ROB, are you referring to some European setup?
February 12, 2014 at 9:52 pm #1002895
twisted- I wrote a long answer which disappeared in the ehter.let’s try again.
As you write, in england , the hot water tank is in the attic and, when you shut off the cold water intake, the hot water still flows out,as it seeks to level with the source. Same in many apartment buildings, where the water tank is on the roof.
Our hot water tanks here in our houses usually is in the lower level and maybe the level aspect is notb apparent. However, you can google anything to do with standard hot water tanks and you will see that there are no pistons, no pumps anywhere in sight in the tank. So, if are you saying that,when the cold water source is shut off (and you are right to say that the cold water drfits to the bottom, being heavier), the hot water does not come out of the faucets (taps for you, new yorkers), I am skeptical about this. Methinks that the hot water will continue as it seeks to find its level with the original source.
BTW- the expansion tank is only tied to the BOILER for the house heating. Our tanks have individual heating, not tied to the boiler.
As far as your “jad soledes bo”. The fact is that,unless you shut off the thermostat, when the water temperature drops below a certain number, the heating will come on. That, again, may very wlel be a true gromo and not even “psik reisha.”
In conclusion- I think that hot water will continue to flow when the cold source is shut. You do not.
February 12, 2014 at 10:04 pm #1002896
ROB, if water has such a good memory, why doesn’t it jump out of my cup to get to the clouds? Yes, it’s true that water, while connected, will go back to the same level it came from. This is based on the gravitational force of the rest of the water bearing down on it.
February 13, 2014 at 12:58 am #1002897
Haleivi:yo answed you own question.only in a situation where the waers are connected does this rule apply,not in your cup.
February 13, 2014 at 3:23 am #1002898
Typical water heaters in the US are designed not to empty unless the drain valve is opened (or when the tank develops a leak just after the warranty runs out). This is by design to prevent the possibility of heating an empty tank.
From what I’ve read, in the UK they often use an indirect water heater where there is no burner in the heater. These systems will not be damaged by running dry so they are allowed to empty. If such a system is installed above the living space the pressure from the cold water inlet is not required to deliver hot water.
February 13, 2014 at 3:30 am #1002899
And it answers you as well. If you shut off the intake then it is disconnected from its source.
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