Hi, I moved to a apartment that has a stately 40-liter electric hot water tank. Previously I had gas water tanks and I assumed it would be similar. The problem is that with the knob at 4 or 5 (maximum) only two minutes of very hot water comes out in the shower, from there warm and cold immediately. It is a thermos of 40 is not for a long shower but it seems very fast time, I tried to make a reset and unplug it or try a knob in other numbers but I do not change the result. I already appreciate your opinions

You can see how long it takes to heat the water, if it takes a short time the thermostat may be bad, and it makes the water warm to a low level but it feels hot, and when you start using it lasts very little as it starts to receive cold water It gradually cools. The initial temperature is important if it is high, but if they changed the thermostat it is unlikely that the two are bad, but not impossible. The pipe that goes inside that makes the inlet water does not mix with the hot water may be broken, but this is inside the pot, and you have no way of seeing, there it uses the guarantee. You have to see that they have no losses, regular size hot water tap. Finally, check if you have a washing machine connected to a spout, of a mixer set, and that the two faucets are open. If so, the connection, you can check to close the hot water tap, and if it closes well check if the problem was solved, you should not have both open taps at the same time ever. also check that nothing is connected to a mixer set and the two open faucets, I said washing machine but it can be any dishwasher appliance etc. check all that and comment please, luck and thanks.

The exit and entrance pipes to the thermos seem to be inverted.

I make an update came a plumber to check the pipe that prevents the mixing of hot water and cold water above and it was ok, the entry and exit position was also ok ... and after that came those of the stately service that they changed the thermostat but it still works the same, hot water less than a minute and warm / cold ... everyone asks me about the pressure and they tell me it's a small thermos but I understand that a 5 minute shower should be able to ... in finish