header tank overflows

[Ponder]

header tank has been overflowing for 3/4 weeks, fitted 2 new valves and floats, done all the adjusting to no avail. Have now fitted gate valve to water "in" and turned valve off, with boiler (Worcester 14/19cbi, new ) turned on to central heating/hot water I have found that the header tank empties to 1" of the bottom, once the boiler is turned off the header tank then refills, Help please it's driving me mad.

 

[Softus]

I apologise in advance - I'm going to be rather pedantic here, but it's all in your best interests...

You say that the water level reduces to 1" from the bottom. This must mean that you have a bottom outlet on the F&E. Please confirm.

You say that this happens when the system is on CH/hot water - what happens when you turn the system off? Does the F&E refill at all?

If so, is your vent loop at a crazy height over the F&E?

If not, I can't understand where the water is going. This is doubly perplexing since I infer that with the inlet to the F&E turned on the water level reaches the overflow, but you say that the float valve isn't faulty.

 

[bster]

I dont know much but if the vent pipe was blocked would this cause the problem as the water would be sucked from the tank by the pump returning once the pump has stopped. (worth a guess, an educated gues i might add ).

 

[Softus]

...the water would be sucked from the tank by the pump due to there being no and ...

Due to there being no ... ?

 

[bster]

edited above post.

Softus its getting late (for me).

please dont tell me i've made another mistake on this post as well

 

[JohnD]

Softus will be beavering away until the first rays of morning sun peep over the mountaintops.

 

[bster]

right my theory about the vent pipe is rubbish, as i've just remembered that you can have a combined feed and vent pipe and the system will works as it should.

i give up

 

[Softus]

Well the dams don't just build themselves you know.

 

[Ponder]

cheers guys for all the info, replaced the hot water cylinder all works fine now, main thing is the overflow is now redundant. The thought is there is pin hole(s) in the coil which was sucking the cold water out of the HW cylinder when the heating is turned off and back flowing into the CH header tank. Hope to find some where that can pressure test the suspect coil just to prove things out.

Cheers ALL

 

[Softus]

Well, pinholes in cylinder coils are commonplace, and the symptoms usually involve the F&E cistern (aka header tank) overflowing, so maybe everyone here, including me, has been a bit slow suggesting that as the cause.

Then again, I look at your two posts on this topic and try to make sense of them, and it's not possible.

And why you haven't posted anything since you asked for advice a week ago is beyond me.

 

[Ponder]

"softus" if you cannot understand the Queens English as per my write ups tough. Please visit my first write up and you will see that on Friday one person read what I had described as the fault and fully understood and replied with holes in the coil and suggested changing the HW cylinder.
Now you can be pedantic and train to be a good plumber or even take English classes.
Thanks to everyone else.

 

[Softus]

"softus" if you cannot understand the Queens English as per my write ups tough.

It amuses me that you think I can't read English. Clearly you're not familiar with my posts.

Please visit my first write up and you will see that on Friday one person read what I had described as the fault and fully understood and replied with holes in the coil and suggested changing the HW cylinder.

Kindly state the user name of that person, so that I can bask in the glow of your ludicrously false reality.

Now you can be pedantic and train to be a good plumber or even take English classes.

Why thank you.

 

[Ponder]