Is it permitted to turn OFF a hot water faucet on shabbos?
Answer:
The answer to the question depends on how the hot water system works. For instance, if the system works on gas, so that turning off the faucet will cause a fire to be lowered or extinguished, it is prohibited to do so. The same applies to similar systems in which turning off the faucet will cause such a reaction. If, however, the system draws from a hot water reservoir (dud shemesh), there is no halachic problem in turning off the faucet.
