Only happening with one bathroom sink, no hot water in toilet tank or bathtub cold faucet or kitchen sink? In large buildings hot water pressure is kept slightly higher than cold so that problems like this can be detected and fixed quickly because of costs involved in hot water loss. Ask your manager if the hot water system pressure was worked on or any new single lever sink faucets installed anywhere at the time your problem started. At a guess the water flow you hear is not an external leak but some sort of cross connect fault that is then slowly dumping through a leaking toilet tank or perhaps some system valve that isn't tightly shut. If this problem is stumping the person hired to fix it, your condo is not hiring very competent people.

The advantages of soft water are... * To eliminate minerals (and deposits) from the service water, the plumbing, the fixtures, and the appliances. * To facilitate the use of less soap and detergents. The cost benefits of soft water are... * Longer service life and reduced maintenance of the plumbing, the fixtures, and the appliances. * Clothes last longer. Common misconceptions about soft water... * Softening ONLY the cold water supplying the water heater leaves hard water in every service line up to the water softener at the water heater and in all cold lines and fixtures and appliances where cold water is available and at every fixture and appliance where cold and hot water are mixed. You are paying for a softener and installation but only protecting your water heater. While a proper whole house softener installation may be more expensive at first in the long run the maintenance and repair/replacement savings realized by softening at the service entrance (whole house) will pay you back big time. Softening only the water supplying the water heater is usually done when a correct (whole house) install is too challenging for the installer or costly for the customer. While some may think that solution is better than no soft water IMO it is not. * Ion exchange water softing does not add salt to the water. That is a fact. Ion exchange softening will add minute amounts of sodium or potassium (based on what you are using as a regenerant) but NO SALT. Either NaCl or KCl, which are salts, are used in the brine tank but the chlorides (which make both compounds a SALT) are flushed down the drain during regeneration. If your water is extremely hard then the higher the hardness the more sodium or potassium ions are exchanged into the water to soften it and discerning pallets can notice that taste but it is not SALT. Installation of a POU Reverse Osmosis unit will eliminate that taste and provide bottled water taste for a modest cost. If a doctor has you on a low (or NO) sodium diet then using KCl (potassium chloride) in the brine tank is an accepted substitute. So, if you're going to spend the money to get soft water why not get what you're paying for?

I have the water heater completely disconnected and hoses running from the pipes sticking out of the wall. The hoses run down into the washing machine. When I turn the main water line on water comes out both pipes at the same pressure. This has nothing to do with a water heater. Since the pipes are inside the wall I cannot check them for a crossover pipe. The last water heater was in 2012 and I don't remember having any problems with that tank type heater. In 2012 I added a tankless water heater and it never worked right. So I decided that I wanted to change back to a tank water heater. As a test and trying to remember which line coming out of the wall was the inlet, I put hoses on it and put them down in the washing machine and turn the water on to see which one produce the Water. Surprise, they both shooting water at the same high pressure. There is the problem.

I honestly don't understand the gas chamber mantra that gets tossed around here. We are physiologically designed to be more sensitive to and more disgusted by the waste of other people than our own. So anytime a person is forced to occupy a space that recently contained someone else's waste it is unpleasant for them. The best way to make it more pleasant is to limit the time any person might have to spend in a room where someone else's waste has recently been. The easiest ways to do that is to limit the purposes of the room used for waste or schedule waste activities so there is no overlap. Increasing the space to dilute the odors doesn't really work that well. If you don't believe me, take a walk near a cow pasture.