More on CH Header Tank Overflow - or Not?

[Terry Fields]

TheScullster had written:

The old ticker sank when I saw a long icicle hanging from one of the >overflows from the loft. > >So I went up in the loft to investigate and discovered that the icicle was >hanging from the CH header tank overflow, rather than the main water store >tank(s). > >Lifting the (somewhat improvised) lid I found that the level in the tank was >fine and that the float valve appeared to be sealing securely. > >As this tank runs fairly warm, I reach the (hopeful) conclusion that the >water escape/icicle is down to condensation in the overflow pipe (approx >1.5m long) rather than a failure.

The last few days have seen drips of water from the CH overflow, and today I am reliably informed by SWMBO that there is an 8" icicle hanging from the overflow pipe.

Slightly concerned by some of the replies to the OP, I've just been up in the loft to check the jockey tank.

Water level is about 2" below the overflow with the heating running, and the water in the tank is cold. Inlet valve was working fine.

However, the amount of condensation on the inside of the tank lid (a snap fit) was impressive, and it stands to reason that there will be condensate in some of the overflow pipe. As the latter has an outfall slope, the condensate will run down the pipe, but as there isn't much of it, it's liable to freeze when it gets to the end - hence the icicle.

Interestingly, when we moved into the house a few months ago, I found the overflow pipe was sagging under the weight of a piece of too-casually laid insulation. I moved the pipe to ease the strain on it, and when I got downstairs there was a small puddle under the outflow. I did think that this was left over from the system commissioning a few years ago, but am now of the opinion that this regularly happens when the outside temperatures fall far enough to cause consensation in the pipe.

I'm going to place a large flowerpot under the icicle, so that if it breaks off the bits will land in it, and also to serve as a reminder not to walk under it.

Temperatures are set to rise in the next day or two, so with any luck the icicle won't be around for too much longer.

TF

[A Plumber]

You only need 4" of water in the header tank, seems like you have to much in yours

[Terry Fields]

That's the level I lowered it to during a recent cleaning-out exercise. Next time I do it I'll lower the level to your recommendation. It might also help with the condensation problem, as there'll be much more surface area available.

TF

[A Plumber]

It is a feed and expansion cistern, so if the water level is too high, as the water gets hot it expands and can go down the overflow. good luck