20 y/o Bungalow, 20 y/o original oil fired boiler, 10 rads of which only 3
are used (kitchen/diner, shower room and my bedroom). The rest of the house
I rarely even go into so no point heating it. The shower room rad is the
closest to the boiler and the first to heat up. It's needs bleeding every
couple of weeks. Yesterday it was almost full of air - just the bottom rail
heating up. The other two never have any air in. There are no zone valves
for the heating so the water has to run round the whole house to get to the
three rads I do use. Just for Fiesta XR2i's and giggles and to double check
I'm not spikkin ******** I've gone round the other 7 rads today which have
never been looked at for two and a half years and not a trace of air in any
of them after all that time.

There are no leaks from that rad, or any other as far as I can tell, or the
boiler but what goes on under the floorboards in the sump under the house
where the pipes run is anyone's guess.

Suggestions as to why air gets into just that one radiator? If the leak was
elsewhere, like under the floor or at the boiler then surely the pipework
would carry at least some of it to the other rads?

If it's a corrosion gas issue then it's vanishingly unlikely to just affect
one rad methinks.
--
Dave Baker

"Dave Baker" wrote in message
...
20 y/o Bungalow, 20 y/o original oil fired boiler, 10 rads of which only 3
are used (kitchen/diner, shower room and my bedroom). The rest of the
house I rarely even go into so no point heating it. The shower room rad is
the closest to the boiler and the first to heat up. It's needs bleeding
every couple of weeks. Yesterday it was almost full of air - just the
bottom rail heating up. The other two never have any air in. There are no
zone valves for the heating so the water has to run round the whole house
to get to the three rads I do use. Just for Fiesta XR2i's and giggles and
to double check I'm not spikkin ******** I've gone round the other 7 rads
today which have never been looked at for two and a half years and not a
trace of air in any of them after all that time.

There are no leaks from that rad, or any other as far as I can tell, or
the boiler but what goes on under the floorboards in the sump under the
house where the pipes run is anyone's guess.

Suggestions as to why air gets into just that one radiator? If the leak
was elsewhere, like under the floor or at the boiler then surely the
pipework would carry at least some of it to the other rads?

If it's a corrosion gas issue then it's vanishingly unlikely to just
affect one rad methinks.

Quick update. Right after posting the above while having a shufti round I
spotted a pipe stub and bleed nipple coming out of the boiler itself. There
was a good bit of air in that too.

20 y/o Bungalow, 20 y/o original oil fired boiler, 10 rads of which only 3
are used (kitchen/diner, shower room and my bedroom). The rest of the house
I rarely even go into so no point heating it. The shower room rad is the
closest to the boiler and the first to heat up. It's needs bleeding every
couple of weeks. Yesterday it was almost full of air - just the bottom rail
heating up. The other two never have any air in. There are no zone valves
for the heating so the water has to run round the whole house to get to the
three rads I do use. Just for Fiesta XR2i's and giggles and to double check
I'm not spikkin ******** I've gone round the other 7 rads today which have
never been looked at for two and a half years and not a trace of air in any
of them after all that time.

There are no leaks from that rad, or any other as far as I can tell, or the
boiler but what goes on under the floorboards in the sump under the house
where the pipes run is anyone's guess.

Suggestions as to why air gets into just that one radiator? If the leak was
elsewhere, like under the floor or at the boiler then surely the pipework
would carry at least some of it to the other rads?

If it's a corrosion gas issue then it's vanishingly unlikely to just affect
one rad methinks.

I also have to bleed by shower room towel rail more far more often than any
other rad, but not to the degree you are doing. I have always put it down to
the fact that it is taller and mounted higher than any of the radiators.

Mike

On 26/01/2015 11:34, Dave Baker wrote:
20 y/o Bungalow, 20 y/o original oil fired boiler, 10 rads of which only
3 are used (kitchen/diner, shower room and my bedroom). The rest of the
house I rarely even go into so no point heating it. The shower room rad
is the closest to the boiler and the first to heat up. It's needs
bleeding every couple of weeks.

When was the last time your system was drained, or had any inhibitor
added to it?

--
Toby...
Remove your pants to reply

In article ,
"Dave Baker" writes:
20 y/o Bungalow, 20 y/o original oil fired boiler, 10 rads of which only 3
are used (kitchen/diner, shower room and my bedroom). The rest of the house
I rarely even go into so no point heating it. The shower room rad is the
closest to the boiler and the first to heat up. It's needs bleeding every
couple of weeks. Yesterday it was almost full of air - just the bottom rail
heating up. The other two never have any air in. There are no zone valves
for the heating so the water has to run round the whole house to get to the
three rads I do use. Just for Fiesta XR2i's and giggles and to double check
I'm not spikkin ******** I've gone round the other 7 rads today which have
never been looked at for two and a half years and not a trace of air in any
of them after all that time.

There are no leaks from that rad, or any other as far as I can tell, or the
boiler but what goes on under the floorboards in the sump under the house
where the pipes run is anyone's guess.

Suggestions as to why air gets into just that one radiator? If the leak was
elsewhere, like under the floor or at the boiler then surely the pipework
would carry at least some of it to the other rads?

If it's a corrosion gas issue then it's vanishingly unlikely to just affect
one rad methinks.

Air that's got dissolved in the water will always come out in the boiler.
You tend to find that bubbles coming out of the boiler do always end up
in the same radiator (not necessarily nearest the boiler), due to the
pipework layout.

What sort of system is it, vented with a small loft header tank,
or sealed with a pressure guage and filling loop or valve?

Do you know if it has inhibitor and how long it's been in there?

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

In article ,
Dave Baker wrote:
Suggestions as to why air gets into just that one radiator? If the leak
was elsewhere, like under the floor or at the boiler then surely the
pipework would carry at least some of it to the other rads?

It does tend to collect at generally the highest point. Assuming it is air
- and not the product of corrosion - there must be a leak somewhere. It
may well only happen when the water is hot and if minor difficult to find
due to it evaporating quickly.

If you can think of a method of pressurizing the system cold, could be
easier to find. If you have thermostatic valves I'd look at those first -
remove the thermostatic part so you can see the actual valve.

--
*How many roads must a man travel down before he admits he is lost? *

Dave Plowman London SW
To e-mail, change noise into sound.

"Andrew Gabriel" wrote in message
...

Air that's got dissolved in the water will always come out in the boiler.
You tend to find that bubbles coming out of the boiler do always end up
in the same radiator (not necessarily nearest the boiler), due to the
pipework layout.

That's interesting. Thank you.

What sort of system is it, vented with a small loft header tank,
or sealed with a pressure guage and filling loop or valve?

The former.

Do you know if it has inhibitor and how long it's been in there?

That's a question I'd love to ask the previous owner and have been intending
to do. I've only been here since May 2012 so I don't know the history but
given the age of the bungalow (early 90s) I doubt if it's been touched since
new. Regardless I think it might be prudent to flush and refill with
inhibitor in the summer when it's all swiched off. I stupidly allowed the
system in my old house to corrode out due to no inhibitor and am determined
to not let that happen again.

As a subsidiary question is it practical to flush the rads in situ without a
pressure flushing rig just by draining/refilling/draining a few times?
--
Dave Baker

On Mon, 26 Jan 2015 11:34:54 -0000, Dave Baker wrote:

If it's a corrosion gas issue then it's vanishingly unlikely to just
affect one rad methinks.

But for some reason gas frequently only ever accumulates in the rad
nearest the boiler. Presumably because hot water can't hold as much
disolved gas as cooler.

Does the expansion tank get warm/hot, is the pump over. May only be a
little dribble when the pump starts or stops but that is enough to
introduce airated water into the system.

The system does have inhibitor in it doesn't it? Can you remember
when it was last topped up? If it's a long time, just bung another
bottle. Pretty sure you can't "overdose".

--
Cheers
Dave.

A flush would be prudent if the inhibitor is old or non-existent. For a system not badly sludged up then chemical cleaners will do the trick. Running water through will help but will not tend to flush out badly sludged radiators. The best method I have found is to remove individual radiators outside and run the hose or use a high pressure machine to remove the sludge. It's a mucky job but if you have the time and the radiators are easy to drain and remove then it really makes a difference. Power flushing by professionals can costs hundreds and I am not convinced it does a better job than I have described above.

Richard

On Mon, 26 Jan 2015 11:34:54 -0000, "Dave Baker"
wrote:


Suggestions as to why air gets into just that one radiator? If the leak was
elsewhere, like under the floor or at the boiler then surely the pipework
would carry at least some of it to the other rads?

When I moved into this house in 1998 all of the radiators needed
bleeding, then after that only a small one at the top of the stairs,
near the airing cupboard, needed bleeding, probably once a year. I
installed an automatic bleeding valve in that one and none of them
have needed doing since.
(http://www.ebay.co.uk/itm/GENUINE-HV...-/171542307976,
search eBay for 171542307976 if the link is mangled.)

On 26/01/2015 12:18, Dave Baker wrote:

"Andrew Gabriel" wrote in message
...

Air that's got dissolved in the water will always come out in the boiler.
You tend to find that bubbles coming out of the boiler do always end up
in the same radiator (not necessarily nearest the boiler), due to the
pipework layout.

That's interesting. Thank you.

What sort of system is it, vented with a small loft header tank,
or sealed with a pressure guage and filling loop or valve?

The former.

Do you know if it has inhibitor and how long it's been in there?

That's a question I'd love to ask the previous owner and have been
intending to do. I've only been here since May 2012 so I don't know the
history but given the age of the bungalow (early 90s) I doubt if it's
been touched since new. Regardless I think it might be prudent to flush
and refill with inhibitor in the summer when it's all swiched off. I
stupidly allowed the system in my old house to corrode out due to no
inhibitor and am determined to not let that happen again.


Well, you've left it nearly 3 years already! Time to get on with it!

It might be worth checking what actually comes out of the radiator,
first. When you next bleed it, stick a lighted match to the 'air' coming
out and see whether it burns. If it does, it's almost certainly hydrogen
- resulting from corrosion - so adding inhibitor is urgent. If it
doesn't, check the fill and expansion tank carefully to see whether the
system is pumping over. If water is flowing out of the vent pipe, back
into the tank, this is *bad* and will almost certainly introduce air
into the system - quite apart from wasting energy and causing
condensation in the loft.

As a subsidiary question is it practical to flush the rads in situ
without a pressure flushing rig just by draining/refilling/draining a
few times?

Not really. Best to remove each rad in turn, take it outside and flash
it out thoroughly with a hose pipe. [Be careful not to spill any black
gunge on the carpets as you carry it out. Best to stuff a bit of kitchen
roll into each each tail.] While each rad is off, open each of its
valves in turn in order to flush out the pipework.
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

In article ,
"Dave Baker" writes:

"Andrew Gabriel" wrote in message
...

Air that's got dissolved in the water will always come out in the boiler.
You tend to find that bubbles coming out of the boiler do always end up
in the same radiator (not necessarily nearest the boiler), due to the
pipework layout.

That's interesting. Thank you.

What sort of system is it, vented with a small loft header tank,
or sealed with a pressure guage and filling loop or valve?

The former.

Do you know if it has inhibitor and how long it's been in there?

That's a question I'd love to ask the previous owner and have been intending
to do. I've only been here since May 2012 so I don't know the history but
given the age of the bungalow (early 90s) I doubt if it's been touched since
new. Regardless I think it might be prudent to flush and refill with
inhibitor in the summer when it's all swiched off. I stupidly allowed the
system in my old house to corrode out due to no inhibitor and am determined
to not let that happen again.

For the sake of 15 quid, I would buy a bottle and pour it in the header
tank now, even if you end up draining it all off in the summer. Even if
it was put in just before you moved in, 3 years is probably pushing it
for a vented system. (In a sealed system that doesn't need topping up,
it can last much longer.)

While you are up there, when the heating is on, check that hot water
isn't running from the vent pipe back into the small header tank (if
it has a vent pipe looped over the top, which most but not all do).
Ideally, do this when the thermostat is calling for heat, but any TRV's
you have will be closing because those rooms are are up temperature.
Depending on system design, this is often the situation where pumping
over is most likely. Also check the tank isn't hot (perfectly OK if it
is slightly warm, as it's heating and expansion of the water in the
system which pushes the excess up into that tank, but it shouldn't be
at radiator temperature as that would also indicate it is pumping over).

As a subsidiary question is it practical to flush the rads in situ without a
pressure flushing rig just by draining/refilling/draining a few times?

Yes, unless they are sludged up. You can easily check for this by feeling
the bottom of a radiator when the system is running and is all up to
temperature. For each radiator, check the inlet and outlet pipes are hot
indicating there is flow through it. Then feel the bottom of the radiator
around the middle. This is where sludge collects and it will be cold (or
noticably cooler than the inlet and outlet pipes) if there's a build up
of sludge there.

The other thing that helps flushing is to force the flushing water
through each radiator one at a time. Do this by fully opening all the
lockshield values, and with the pump running, turning off all the
radiators except one at a time. You will either need to rebalance the
system afterwards, or before opening the lockshield valves, count the
number of turns to fully close each one and record this, setting it
back to the same position afterwards. You need to record this in
fractions of a turn, as some may only be opened a quarter of a turn,
or even less for a small radiator near the boiler. Opening all the
lockshield valves also serves to release any debris caught in them,
as they are often the narrowest openings in the water paths in a
system.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

Also if that is the highest and the first and there was air at the boiler,
then to me that says its the boiler itself and the boiler and the first rad
grabs all the air. If the first rad now goes a longer time now you bled the
boiler end, then that I'd have thought points the finger at something odd in
boiler land.
Brian

--
From the Sofa of Brian Gaff Reply address is active
"Toby" wrote in message
...
On 26/01/2015 11:34, Dave Baker wrote:
20 y/o Bungalow, 20 y/o original oil fired boiler, 10 rads of which only
3 are used (kitchen/diner, shower room and my bedroom). The rest of the
house I rarely even go into so no point heating it. The shower room rad
is the closest to the boiler and the first to heat up. It's needs
bleeding every couple of weeks.

When was the last time your system was drained, or had any inhibitor added
to it?

--
Toby...
Remove your pants to reply

"Andrew Gabriel" wrote in message
...
For the sake of 15 quid, I would buy a bottle and pour it in the header
tank now, even if you end up draining it all off in the summer. Even if
it was put in just before you moved in, 3 years is probably pushing it
for a vented system. (In a sealed system that doesn't need topping up,
it can last much longer.)

While you are up there, when the heating is on, check that hot water
isn't running from the vent pipe back into the small header tank (if
it has a vent pipe looped over the top, which most but not all do).
Ideally, do this when the thermostat is calling for heat, but any TRV's
you have will be closing because those rooms are are up temperature.
Depending on system design, this is often the situation where pumping
over is most likely. Also check the tank isn't hot (perfectly OK if it
is slightly warm, as it's heating and expansion of the water in the
system which pushes the excess up into that tank, but it shouldn't be
at radiator temperature as that would also indicate it is pumping over).

As a subsidiary question is it practical to flush the rads in situ
without a
pressure flushing rig just by draining/refilling/draining a few times?

Yes, unless they are sludged up. You can easily check for this by feeling
the bottom of a radiator when the system is running and is all up to
temperature. For each radiator, check the inlet and outlet pipes are hot
indicating there is flow through it. Then feel the bottom of the radiator
around the middle. This is where sludge collects and it will be cold (or
noticably cooler than the inlet and outlet pipes) if there's a build up
of sludge there.

All excellent advice, thank you. The rads feel good at the bottom centre but
nonetheless I think when the warmer weather comes around I'll give the whole
system a going over and depending on what colour the water is that comes out
of the drain cock I might take each rad out and give it a good blast through
with the pressure washer.

My lack of TLC with the system in my last house for 20 years, ignoring the
black crap that came out every time I had to drain it to fix a leak and
never using inhibitor because there was always just "one more job to do"
before I could call the system finished resulted in a decidedly moist lounge
carpet which I traced back to a 2 foot jet of water spraying horizontally
out of a pinhole in a completely rusted through rad onto the back of the
cupboard it was hidden behind followed shortly after by the boiler heat
exchanger cracking due to it being half full of rusty sludge. I managed
without heating for the last few years until I sold it as a do'er upper but
that bottle of Fernox I never put in probably cost me several thousand quid
plus a thoroughly miserable cold existence every winter managing on gas and
electric fires. I ain't going there again. Penny wise - pound foolish.
--
Dave Baker

On 26/01/2015 17:29, Dave Baker wrote:

"Andrew Gabriel" wrote in message
...
For the sake of 15 quid, I would buy a bottle and pour it in the header
tank now, even if you end up draining it all off in the summer. Even if
it was put in just before you moved in, 3 years is probably pushing it
for a vented system. (In a sealed system that doesn't need topping up,
it can last much longer.)

While you are up there, when the heating is on, check that hot water
isn't running from the vent pipe back into the small header tank (if
it has a vent pipe looped over the top, which most but not all do).
Ideally, do this when the thermostat is calling for heat, but any TRV's
you have will be closing because those rooms are are up temperature.
Depending on system design, this is often the situation where pumping
over is most likely. Also check the tank isn't hot (perfectly OK if it
is slightly warm, as it's heating and expansion of the water in the
system which pushes the excess up into that tank, but it shouldn't be
at radiator temperature as that would also indicate it is pumping over).

As a subsidiary question is it practical to flush the rads in situ
without a
pressure flushing rig just by draining/refilling/draining a few times?

Yes, unless they are sludged up. You can easily check for this by feeling
the bottom of a radiator when the system is running and is all up to
temperature. For each radiator, check the inlet and outlet pipes are hot
indicating there is flow through it. Then feel the bottom of the radiator
around the middle. This is where sludge collects and it will be cold (or
noticably cooler than the inlet and outlet pipes) if there's a build up
of sludge there.

All excellent advice, thank you. The rads feel good at the bottom centre
but nonetheless I think when the warmer weather comes around I'll give
the whole system a going over and depending on what colour the water is
that comes out of the drain cock I might take each rad out and give it a
good blast through with the pressure washer.

My lack of TLC with the system in my last house for 20 years, ignoring
the black crap that came out every time I had to drain it to fix a leak
and never using inhibitor because there was always just "one more job to
do" before I could call the system finished resulted in a decidedly
moist lounge carpet which I traced back to a 2 foot jet of water
spraying horizontally out of a pinhole in a completely rusted through
rad onto the back of the cupboard it was hidden behind followed shortly
after by the boiler heat exchanger cracking due to it being half full of
rusty sludge. I managed without heating for the last few years until I
sold it as a do'er upper but that bottle of Fernox I never put in
probably cost me several thousand quid plus a thoroughly miserable cold
existence every winter managing on gas and electric fires. I ain't going
there again. Penny wise - pound foolish.

It's best to add the inhibitor to the towel rad, as they usually have
removable plugs at the top, so shut the rad off (both valves!) bleed it
until no more water comes out, then remove one of the plugs, syphon some
water out into the handy nearby bath/basin/loo! and then funnel the
inhibitor in.

If you add it to the expansion tank, it may end up mostly staying up
there rather than getting around the system immediately.


--
Toby...
Remove your pants to reply

In article ,
Dave Baker wrote:
What sort of system is it, vented with a small loft header tank,
or sealed with a pressure guage and filling loop or valve?

The former.

Have you checked it's not pumping over? If you've shut down some rads,
it's more likely.

--
*If I throw a stick, will you leave?

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Baker" wrote in message
...
20 y/o Bungalow, 20 y/o original oil fired boiler, 10 rads of which only 3
are used (kitchen/diner, shower room and my bedroom). The rest of the
house I rarely even go into so no point heating it. The shower room rad is
the closest to the boiler and the first to heat up. It's needs bleeding
every couple of weeks. Yesterday it was almost full of air - just the
bottom rail heating up. The other two never have any air in. There are no
zone valves for the heating so the water has to run round the whole house
to get to the three rads I do use. Just for Fiesta XR2i's and giggles and
to double check I'm not spikkin ******** I've gone round the other 7 rads
today which have never been looked at for two and a half years and not a
trace of air in any of them after all that time.

There are no leaks from that rad, or any other as far as I can tell, or
the boiler but what goes on under the floorboards in the sump under the
house where the pipes run is anyone's guess.

Suggestions as to why air gets into just that one radiator? If the leak
was elsewhere, like under the floor or at the boiler then surely the
pipework would carry at least some of it to the other rads?

If it's a corrosion gas issue then it's vanishingly unlikely to just
affect one rad methinks.
--
Dave Baker

You might find air is being sucked down the expansion pipe by the pump if
the system is not correctly designed.
(This is the pipe that curls over the top of the header tank.)
Also check that there is sufficient water in the header tank , it needs to
be around one third to a quarter full.
Stopping this might be as simple as reducing the pump speed (switch on
pump.)

If already running at minimum speed, try throttling the pump using one of
the isolator valves.
This is a temporary solution only, there will need to be a permanent fix.


This is a quite likely one as it's made worse by turning most off the
radiators off as you have done making the pump "too big" for the remaining
system.

In article ,
Toby writes:
It's best to add the inhibitor to the towel rad, as they usually have
removable plugs at the top, so shut the rad off (both valves!) bleed it
until no more water comes out, then remove one of the plugs, syphon some
water out into the handy nearby bath/basin/loo! and then funnel the
inhibitor in.

If you add it to the expansion tank, it may end up mostly staying up
there rather than getting around the system immediately.

Each time the radiators heat up and cool off, it pushes water up into
the expansion tank and draws it back again. After a few days, it will
be well drawn into the system.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On 26/01/2015 12:18, Dave Baker wrote:

"Andrew Gabriel" wrote in message
...


What sort of system is it, vented with a small loft header tank,
or sealed with a pressure guage and filling loop or valve?

The former.

Make sure that you are not over pumping and cycling aerated water around
the header tank.

I've found that filling/emptying the system a few times alone does
little to get the sludge from the radiators.

Try also fitting an auto-bleed valve to the problem radiator.



--
mailto: news {at} admac {dot] myzen {dot} co {dot} uk

On 26/01/2015 12:18, Dave Baker wrote:

As a subsidiary question is it practical to flush the rads in situ
without a pressure flushing rig just by draining/refilling/draining a
few times?

Its fairly easy to do on sealed systems, but not quite as easy to do
effectively on vented ones. Although if you temporarily cap of the feed
and vent connections to the header tank, then you can mains pressure
flush it like a sealed one. See

http://wiki.diyfaq.org.uk/index.php?...ating_flushing

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

"Roger Mills" wrote in message
...
On 26/01/2015 12:18, Dave Baker wrote:

"Andrew Gabriel" wrote in message
...

Air that's got dissolved in the water will always come out in the
boiler.
You tend to find that bubbles coming out of the boiler do always end up
in the same radiator (not necessarily nearest the boiler), due to the
pipework layout.

That's interesting. Thank you.

What sort of system is it, vented with a small loft header tank,
or sealed with a pressure guage and filling loop or valve?

The former.

Do you know if it has inhibitor and how long it's been in there?

That's a question I'd love to ask the previous owner and have been
intending to do. I've only been here since May 2012 so I don't know the
history but given the age of the bungalow (early 90s) I doubt if it's
been touched since new. Regardless I think it might be prudent to flush
and refill with inhibitor in the summer when it's all swiched off. I
stupidly allowed the system in my old house to corrode out due to no
inhibitor and am determined to not let that happen again.


Well, you've left it nearly 3 years already! Time to get on with it!


And? This is uk.d-i-y:-)

--
Adam