Hot water in cold water storage tank

[stevie-c]

My cold water storage tank feeds the hot water cylinder and also a shower with a pump. On several occassions the shower has been too hot to use. My initial reaction was that the shower was faulty but decided to do a bit of diy investigating and discovered that the cold water storage tank contained hot water. It appears that heat is tracking back up the feed pipe from the hot water cylinders as this pipe is very hot.
Is this possible? If so what can be done?

 

[TexMex]

It's possible that your hot water tank has not been installed correctly. The cold water feed (from the header tank) should enter the hot water tank at the bottom. The feed to your taps (and the vent pipe) should exit from the top.

You will therefore have two pipes from the hot water tank reaching the header tank. The cold water feed (which should be fitted at the bottom of the header tank) and the vent pipe (that should be positioned over the top of the header tank).

If these two pipes were connected the wrong way around, then, as the water in your hot water tank heats up, it will heat up the header tank by convection.

So to recap. The bottom pipe on your hot water cylinder should be connected to the bottom of your header tank. The top pipe should feed your taps, and have a teed off pipe leading to an open pipe above the header tank.

There are other situations that can lead to the header tank getting warmed up, but since you are saying that it is getting "HOT", I'd check this out first.

 

[TexMex]

Another possibility that I have just thought of, is that you have inadvertantly taken the feed for your shower from the central heating header/expansion tank. Obviously this will get hot every time the central heating boiler is active. There must be a million reasons why you shouldn't do this so I hope you haven't.

 

[stevie-c]

That was the first thing I checked. The cold water feed is definately connected correctly at the bottom of the tank and vent from the top. The cold water shower feed has been taken from the correct tank. I am sure the heat is coming up the cold water feed as the pipe gets quite hot.

 

[kevplumb]

would think the vent is blocked
is your f&e tank higher than the h/w feed tank

 

[ChrisR]

What angle/direction is the pipe coming out of the top of the HW cylinder?

 

[PEDANTICVINDICTIVEMAN]

Where did "my" reply to this topic go

 

[kevplumb]

here //www.diynot.com/forums/viewtopic.php?t=17285

 

[PEDANTICVINDICTIVEMAN]

Oh right, dejavoo on the postings

 

[DIYnot]

Continue this topic here please.

Thank you.