WHY DOES MY CH HEADER TANK KEEP FILLING????

[macgee]

So, the situation is that the CH header tank keeps filling.
There is no problem with the ball valve and also the coil in the hot water cylinder hasn't gone.
When the tank does fill, it comes from the cold feed off the bottom of the tank, not the main.
You can actually feel the water rise from inside the tank. This all happens when the boiler is running (ie pump running).
The pump is on the right way round, the cold feed and vent are in the correct position, the system has worked for years, no problem. Now this happens.

Any ideas???????

 

[seco services]

what makes you say your coil hasn't gone.

 

[gasmick2]

The coil has got a pinhole in it !!! turn off the gate valve to the cold feed for a while, the see if it comes out of the expansion back into the tank ??
the water in the main header tank is trying to reach the same level, backing up into the lower tank , as it would in a plastic pipe thats how a water level works, I have seen dozens of them over the years,

mick

 

[macgee]

The only thing that tells me that the cylinder hasn't gone is the fact that the tank only fills with the pump running. If I turn the boiler off. the tank doesn't fill, no matter how long its left. Surely if the cylinder had gone, it would fill with the boiler off, ( all be it a lot slower).

 

[powell30]

Does the level receed when you switch off the pump? If so, blockage in line after pump.....if not, coil split.

 

[macgee]

To be honest, I cant remember whether the water does receed after pump has stopped. I just assumed it did, will check though.
But I still think that if the cylinder coil has gone, it would be over flowing now as the hot water has been on for 24hrs on the immersion, with no problems.
From speaking to engineers today, it looks as though it must be a blockage in the system, question is where abouts, possibly the vent pipe???????

Any ideas?

 

[liverpoolboy]

if you had a blockage in the vent pipe you're cylinder could start to implode!!

 

[seco services]

could what ?

 

[liverpoolboy]

implode - inside. is very rare but heard of it happening before!!

 

[macgee]

So are you saying that there could be a blockage, just not in the vent pipe. If so, where???

 

[seco services]

you said its cold water entering the tank not hot

 

[macgee]

the water is hot if the boiler has been running for a while yes, coming through the cold feed outlet on the bottom of the tank.

 

[seco services]

did you try shutting the gate valve supplying the cylinder from the cws tank in loft and running the boiler?

 

[macgee]

No, did think of it though but didn't see what it would tell me?

 

[seco services]

it would tell you for sure if the coil has gone