Guidelines for shower on Yom Tov and usage of a solar water heater

Since this year we have a two-day Yom Tov followed by Shabbos, I would like to know if I am allowed to shower on Yom Tov. Additionally, I've recently installed solar panels that heat water using sunlight, and I'm wondering if this affects the halachic ruling?

Thank you for your question.

Its important to know that the Halochos of being able to wash oneself are very complex and your question about being able to use the water from the solar water heater adds another layer of complexity so I will give you a clear guide to each case whether its a child or adult or using hot or cold water and if the water was heated in a pot on the stove, or in a solar water heater.

Washing a child .

If one usually washes the child every day, (if one generally doesn’t wash the child daily then, then the halachos of this child regarding washing is like those of adults). Then one may wash him with hot water that was warmed before Yom Tov, or even water that was warmed on Yom Tov for the purpose of washing dishes or drinking. Some of the water should be used for washing dishes; the rest can be poured into the bath and mixed with cold water to wash the baby.

Some are lenient and open the hot water tap of the solar water heater - Dud Shemesh (without closing the cold water tap that fills the vat) if they do so with the intention to drink the hot water or to wash dishes, then one does not need to reprimand them for doing so. Therefore, if one who opens the hot water tap of the bath then washes dishes using this water and afterward washes the baby with the rest of the water, we do not reprimand him.

For adults:

Cold water ;

Washing a minority part of the body (Mi’ut Ha’guf)

Lechatchillah according to all customs, one can wash a minority of the body using cold water.

Washing the entire body

According to the Sephardi custom is permitted.

According to the Ashkenazi custom, it is only permitted in a case where one is uncomfortable (be’tsar)

Hot water :

Washing the entire body :

For Ashkenazim, it is forbidden.

For Sephardim, it is only permitted if the water was heated before Yom Tov in a pot on the fire; then it would be permitted to pour the water from the pot into the bath on Yom Tov.

Washing the body limb by limb :

Washing limb by limb means that one first washes, for example, the arm, then dries it, then washes the other arm, and dries it, and so forth. This is only permitted with water that was heated before Yom Tov, and on Yom Tov one pours the water into the bath and then washes limb by limb. For Ashkenazim this permitted only in a case where one is uncomfortable (be’tsar).

Face, hands and feet :

It is permitted to wash ones face, hands, and feet even with water that was heated on Yom Tov; for example, one may warm a pot of water on Yom Tov, then pour it into the bath, and then wash one’s face, hands, and feet.

Regarding the solar water heater (Dud Shemesh) :

Until now, we have only spoken about heating water with a pot on a stove. But what about the water that was heated in a solar water heater? This is a major controversy among the Poskim, since when opening the hot water, the vat then fills with cold water that will be heated on Yom tov, (considered cooking), and since that is not the water I am using, it is considered cooking water that is not used on Yom Tov (Shelo Le’tsorech). Therefore, if one washes one's face, hands, and feet with water from the vat, it is not le’chatchila, since cold water will enter as explained. If one is able to close the cold water tap that fills the vat, then it would be le’chatchilah to wash one's face, hands, and feet using the hot water of the solar water heater.

Washing a minority of the body :

It is permitted to use water that was heated before Yom Tov.

Some are lenient and heat water using a pot on the fire or heat water in the boiler using a “Shabbos time switch”, and they have whom to rely on.

Those who want to use the hot water from the solar water heater (Dud Shemesh) for this purpose le’chatchilah should turn off the cold water tap that fills the vat; if they don't, then one does not have to reprimand them.

Teachings of Ha'gaon Harav Fried Shalita