Can I cook with hot water from the tap: an expert explanation

The other day, a neighbor – a curious lady in all respects – told another secret of saving. “Imagine,” she said. – I started cooking with hot water from the tap, and the electricity bill decreased noticeably. Try it – you will be surprised yourself. “

The advice sounded strange, but the situations are different: sometimes the time is running out, sometimes they just turned off the cold water. Is it possible in such cases to pour hot water from the tap into the kettle or cook vegetables on it – we understand the issue.

Yes, hot tap water in general must comply with GOST R 51232-98 “Drinking water”. It should be transparent, clean, colorless and odorless. But even in St. Petersburg, where, according to Rospotrebnadzor, the cleanest liquid in Russia flows from the taps (river narrow-clawed and Australian red-clawed crayfish monitor its condition!), Experts do not recommend using hot water for cooking.

Why hot water can be dangerous

Condition of heating networks… Not only in the city on the Neva, but also in almost all cities of Russia, it leaves much to be desired. Over decades of operation, a huge amount of corrosive suspensions and rust has been collected in hot water supply pipes. And it takes years to replace them.

Old technology… The main enemy of metal, which triggers the process of pipe corrosion, is oxygen. And, alas, the technology for removing oxygen from water has not been implemented at most Russian CHPPs. After all, for this it is necessary to update the water supply enterprises or use modern pipes. Both are costly for the budget, while nowadays economy is a religion.

Outdated intra-house communications… Do you remember the last time the pipes were changed in your apartment? And by the way, their service life does not exceed 30 years, subject to many factors. In fact, they fail much earlier. But even the replacement of communications inside the housing will not solve the problem.

Chemical processing… To prevent chemical processes leading to the appearance of scale on pipes and the development of corrosion, water supply companies additionally treat heated water. Substances are added to it that reduce the risk of scale formation. In addition, they help remove heavy metals from the lines and dissolve large particles that can lead to equipment damage.

• Silifos and sodium silicate… Reagents that make water clear and prevent limescale build-up. The same sodium silicate (known as E550) was used until recently in the production of milk powder and bakery products. But with prolonged use, they can cause allergic reactions and exacerbation of chronic pathologies.

• Chlorine compounds. May get into water when flushing hot water systems. Chlorine causes eating disorders, as well as allergic skin reactions – everyone who in Soviet times visited pools with chlorinated water knows firsthand.

• Lead. It gets into the water from the welds of metal pipes. With prolonged use, it accumulates in the body and leads to diseases of the central nervous system and hypertension.

• Polyacrylamide. Part of cleaning reagents. It is considered a carcinogen with all the ensuing consequences. It gets into water in small doses, but still little pleasant.

And if you boil?

Boiling hot tap water is also not a panacea. After all, the reagents do not disintegrate and do not evaporate under the influence of high temperatures. So for cooking, it is still better to use cold water passed through a filter. And in order to reduce the risks as much as possible, experts advise: if you have not used the tap for six hours or more, rinse the pipes with cold water. The water should be drained from 30 seconds to 5 minutes, until it becomes as cold as possible. In this case, you will drain the stagnant water, which could accumulate harmful substances contained in the pipes overnight.

The presence of a gas water heater or a boiler in the apartment is also not an argument. Both “gadgets” refer to ways of organizing an autonomous hot water supply system. In this case, the principle of flow heating is used in the gas column, when the water is heated while moving through a heat exchanger made of stainless steel or copper. Accordingly, the risk of harmful substances or metal corrosion products entering the water is reduced, but it cannot be completely excluded. But in the boiler, not only the flow-through, but also the accumulative heating principle is used. And in this case, due to the increase in the contact time, the chance of harmful substances entering the water is higher.

Quality expert NP Roskontrol