Understanding hot water tank and valves

galycos

Hi

I have an issue with the hot water and I am trying to understand better how the hot water works in my apartment. I am not an expert on this, but I tried to do a bit of research first to understand this better. I have storage heaters and a hot water cylinder whit 2 immersion elements.

I wanted to attach some pictures of the hot water tank and the pipes coming in and out, plus the pump installed but I had to create a new account and I wont let me. You can put http before this addresses and you will be able to see them.

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There is a cold water tank in top of the cylinder, not seen in the pictures. This tank seems fed by the mains. The pipe coming from the top of the cylinder goes there too as a vent pipe. There is an exit pipe that goes to valve (2) in the picture.

I heat the water of the tank between around 5 and 7:30 am , the last hours of the cheap electricity time.

One of the problems is that in the morning, hot water comes from the cold taps in the bathroom. I am sure it depends on the way the valves are set up. (valves are all fully open).

The way I understand this is this:

-Cold water from the mains enters the tank on the bottom. (4) is fully open.

-When I turn the hot tap on, the pump kicks in. Hot water exists the tank passing through (1). This one is fully open too.

-When I turn the cold water tap on in the bathroom the pump kicks in too, but this water comes not from the mains but from the cold tank on top on the cylinder, passing via (2) and to the pump.

If the water in the toilet is hot when turning only the cold tap, then hot water must be coming from the cylinder, and mixing in the pump. I see no other reason. I checked the cold tank up when it happens and the water is very cold there, so is the vent pipe.

If I close fully the valve (1) and open fully (2) then the water comes colder. Obviously I cannot leave them like that, but there must be some way to set all these valves properly so I do not have hot water on the cold taps in the morning (cant even wash my face).

Another problem I have sometimes is that in the evening water is not hot enough for a shower and I believe it all comes down to how there valves are set up as well.

-Can anyone explain how this works and how the valves should be set up?

Calahonda52

Is this a new problem?

I see 4 valves as follows:
1 is the hot feed from cylinder to pump.

There are 3 on the wall and its not clear which number related to which so lets take it from the front
Brass stop cock which cuts off the rising main to cold water header tank
the next one in from front looks like cold water feed to bottom of HW tank
the last, innermost one looks like cold water feed to cold side of pump.

All four need to be open for it to work.
Which immersion coil do you use to heat the water?
Are they both working
I have uploaded the pics for ease of use by the experts

K.Flyer

As Calahonda says, all valves should be fully open.
The most likely problem is your pump. A common problem with that model is the seal between the two pumping chambers leaking and allowing hot water to blend into the cold side.
Also, the heating elements that you have on that cylinder are the short 11" types. Having them heating water for a couple of hours in the morning for morning showers will not leave you with much or any hot water for evening showers.
Also note the connection point from the pump to the hot water cylinder, it is almost 1/4 way down from the top of the cylinder.
This means that the hot water volume above that connection cannot get to the pump and may be going to waste.
To check that hot and cold in the bathroom are plumbed correctly. Make sure that you have plenty of hot water and run the hot tap in your basin at the same time as the cold on the bath, there should be clear distinction between them. While doing this flush the w.c. a couple of times, water going into the cistern should be cold.
Any real deviation from the above and your pipework may need alterations.

galycos

Thanks for all your replies. I will book a plumber to have a look at the pump as it seems to mix hot and cold inside, possible the chamber is broken as you said.