I am thinking one (hopefully not both) of the above is the cause of my
problems. Symptoms being a fairly constant drip from the discharge pipe out
doors and steady drop in pressure in the system.

The boiler is an old Ferroli 77FF IIRC.

I am short on free time but need to get this sorted as am moving house.

I am hoping to confirm diagnosis. Gauge how much it will cost to have an
engineer fix this. Gauge whether it is a possible DIY job. I am competent
(IMHO) with general copperwork plumbing and as a general DIYist.

I will take a closer look at the valve shortly and am giving over tomorrow
to get this fixed if possible and necessary whether calling engineers or
DIY.

Comments please.

"BigBird" wrote in message
...
I am thinking one (hopefully not both) of the above is the cause of my
problems. Symptoms being a fairly constant drip from the discharge pipe out
doors and steady drop in pressure in the system.

The boiler is an old Ferroli 77FF IIRC.

I am short on free time but need to get this sorted as am moving house.

I am hoping to confirm diagnosis. Gauge how much it will cost to have an
engineer fix this. Gauge whether it is a possible DIY job. I am competent
(IMHO) with general copperwork plumbing and as a general DIYist.

I will take a closer look at the valve shortly and am giving over tomorrow
to get this fixed if possible and necessary whether calling engineers or
DIY.

Comments please.
Well thinking about it obviously the valve must be faulty to release water
at such low pressures. Anyway as can be expected testing the valve has
exacerbated the fault. Now more than a steady drip.

I have a spare on standby now and inhibitor too. It is just a matter of
whether there is something which prevents it being a DIY job and whether the
expansion chamber is also faulty. I'm still thinking it possible a faulty
chamber may have came before a faulty valve.

I have a spare on standby now and inhibitor too. It is just a matter of
whether there is something which prevents it being a DIY job and whether
the
expansion chamber is also faulty.

Yes, it's all possible. When you've got the system drained down, check the
precharge on the expansion vessel (usually 0.75 bar). If you can't
pressurise it, or water leaks out of the air hole, then it is shot.

Christian.

You're thinking on the right lines.

Sometimes you can clear the seat of the prv by geting th ehating roasting hot switching off the boiler and manually blowing a good jet out of the prv. If this fails you do have to change it.

As a secondary issue check the expansion vessel. If it is working correctly the pressure in the system should rise about 1/2 a bar from cold to hot, this depends on the size of your system. If it only rises to around 1/2 a bar greater, then no need to investigate further.

If it is faulty, let all the air out (if there is any) of the Shrieder valve (bike pump valve). If water comes out you need a new vessel. If air or no air but no water either, drain your system until there is 1/2 a bar showing on your built in guage. Get your bike pump and manually pump up the vessel a further 1/2 to 1 bar i.e. watch the guage go up by that amount. (whatever pressure your manufacturers instructions advise, 0.75 bar if no advice.).

On Mon, 24 Jan 2005 13:58:22 +0000, BigBird wrote:

I am thinking one (hopefully not both) of the above is the cause of my
problems. Symptoms being a fairly constant drip from the discharge pipe out
doors and steady drop in pressure in the system.

The boiler is an old Ferroli 77FF IIRC.

I am short on free time but need to get this sorted as am moving house.

I am hoping to confirm diagnosis. Gauge how much it will cost to have an
engineer fix this. Gauge whether it is a possible DIY job. I am competent
(IMHO) with general copperwork plumbing and as a general DIYist.

I will take a closer look at the valve shortly and am giving over tomorrow
to get this fixed if possible and necessary whether calling engineers or
DIY.

Comments please.
See below.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html

"Paul Barker" wrote in message
...

BigBird Wrote:
"BigBird" wrote in message
...-
I am thinking one (hopefully not both) of the above is the cause of my
problems. Symptoms being a fairly constant drip from the discharge pipe
out
doors and steady drop in pressure in the system.

The boiler is an old Ferroli 77FF IIRC.

I am short on free time but need to get this sorted as am moving
house.

I am hoping to confirm diagnosis. Gauge how much it will cost to have
an
engineer fix this. Gauge whether it is a possible DIY job. I am
competent
(IMHO) with general copperwork plumbing and as a general DIYist.

I will take a closer look at the valve shortly and am giving over
tomorrow
to get this fixed if possible and necessary whether calling engineers
or
DIY.

Comments please.-
Well thinking about it obviously the valve must be faulty to release
water
at such low pressures. Anyway as can be expected testing the valve has
exacerbated the fault. Now more than a steady drip.

I have a spare on standby now and inhibitor too. It is just a matter
of
whether there is something which prevents it being a DIY job and
whether the
expansion chamber is also faulty. I'm still thinking it possible a
faulty
chamber may have came before a faulty valve.


You're thinking on the right lines.

Sometimes you can clear the seat of the prv by geting th ehating
roasting hot switching off the boiler and manually blowing a good jet
out of the prv. If this fails you do have to change it.

As a secondary issue check the expansion vessel. If it is working
correctly the pressure in the system should rise about 1/2 a bar from
cold to hot, this depends on the size of your system. If it only rises
to around 1/2 a bar greater, then no need to investigate further.

If it is faulty, let all the air out (if there is any) of the Shrieder
valve (bike pump valve). If water comes out you need a new vessel. If
air or no air but no water either, drain your system until there is 1/2
a bar showing on your built in guage. Get your bike pump and manually
pump up the vessel a further 1/2 to 1 bar i.e. watch the guage go up by
that amount. (whatever pressure your manufacturers instructions advise,
0.75 bar if no advice.).


Thanks to all who replied.

The importance of RTFM has once again been proven, if only I had the manual.
I do actually have pdf of very similar model now I know what I'm looking
at.

Long story short I replaced the PRV without a problem. At £15 this wasn't a
problem. I have also recharged the expansion chamber following the
instructions/advice in the FAQ and above. There was next to no pressure in
there. Whether it is damaged internally I have yet to find out.

Unfortunately the new PRV seems no better than the old. On first use it let
water through at just over 2Bar. Later I noticed it letting water through at
just over 1Bar. How do these actually work. Could I have damaged it already
and how. Any liquid I have collected from the discharge has not contained
any obvious contaminants.

I could understand the one I removed failing. There was a certain amount of
sludge like material at the entrance to the valve.

I shall see if a couple of test discharges at full working temp help else I
guess I need to see if I can get hold of another one...

....got called away time passed and I have actually tried this a little
earlier now. Problem with PRV seems to have gone away.

Shall see how things go. Cheers.