>
> Now customer has hot water & central heating. However I noticed that the
> vent pipe for the central heating is constantly running - pumping over,
the
> water in the header tank roasting. This had been going on all day, and
> condensation now dripping off roof in attic. What could cause this to
happen
> to a previously working system?
>
> The vent (22mm) and feed (15mm) pipes connect together within 4" of each
> other at the inlet to the pump. Although the vent is pumping over, the
tank
> is not filling, so the water going in to the tank through the vent must be
> leaving through the feed pipe. It's as if the connection between the two
> pipes at the pump inlet is blocked... only thing I can think of, but
doesn't
> seem likely.
>
> Please help!!
>
> Cheers
> Colin

There is a good chance that the cold feed pipe is blocked up. Check the f&e
tank to see if there is sludge on the bottom, if so, there is a good chance
it will be blocked further down too.
I remember finding a similar problem to this, we replaced the said pipe and
hey presto !! bob's me grannie !!!!)

mike

"BB king" <robowen(no spam)1@(no spam)v21.me.uk> wrote in message
news:(E-Mail Removed)...
>
>
> >
> > Now customer has hot water & central heating. However I noticed that the
> > vent pipe for the central heating is constantly running - pumping over,
> the
> > water in the header tank roasting. This had been going on all day, and
> > condensation now dripping off roof in attic. What could cause this to
> happen
> > to a previously working system?
> >
> > The vent (22mm) and feed (15mm) pipes connect together within 4" of each
> > other at the inlet to the pump. Although the vent is pumping over, the
> tank
> > is not filling, so the water going in to the tank through the vent must
be
> > leaving through the feed pipe. It's as if the connection between the two
> > pipes at the pump inlet is blocked... only thing I can think of, but
> doesn't
> > seem likely.
> >
> > Please help!!
> >
> > Cheers
> > Colin
>
> There is a good chance that the cold feed pipe is blocked up. Check the
f&e
> tank to see if there is sludge on the bottom, if so, there is a good
chance
> it will be blocked further down too.

That wouldn't cause the reported problem though: there'd be nowhere for the
water being pumped over to go.

I encountered this problem on a system which (a) had the pump set at max -
turning it down stopped it pumping over (b) the opening on the vent pipe was
just an inch or so above the level of water in the header tank, which meant
that as soon as pumping over started it would only require a pressure
difference of 1" WG or so to maintain the flow. This was sorted by
shortening the downturned part of the vent pipe and lowering the level of
water in the tank.



--
John Stumbles
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