Hi all,

I posted this over in alt.hvac a couple of weeks ago and didn't get
much help.
Just a bunch of smart ass answers so I thought I'd try it here.

My house is heated with hot water baseboard radiators. The hot water
is supplied by a boiler furnace with circulation pump. The furnace
has an automatic fill valve that is kept in the off position unless
the system needs water. It is them manually opened until proper
pressure is achieved. The burner comes on at about 150 degrees and
goes out at 160 degrees. I try to maintain about 18psi at 160 degrees
system pressure. The safety blow valve is set to blow at 35psi. It
has an air purge valve at the top of furnace just below the floor
above it (about 10 feet from basement floor).
The air purge valve is new and so is the expansion tank. The
expansion tank pressure seems to match the boiler pressure.

Here's the problem. Every couple of days the system pressure has
dropped to about 10 or 11 psi at 160 degrees. This effects the
efficiency of both the radiator heat as well as the potable hot water
(which is heated by the boiler).
I open the fill valve, purge the air and close it all back up at 20psi
or so
at 160 degrees. All is well for another couple of days until the
pressure is back down and I repeat the process.

I don't see any leaks, no water dripping from ceilings or pooling
anywhere that I can see. One room of the house is a concrete slab
floor (converted carport). It has heating pipe within the concrete
slab.

I keep adding water and purging and the pressure keeps dropping. It's
an endless cycle.
What could cause the pressure to
keep dropping?
I'm out of ideas.

Thanks in advance,

In article . com, coustanis wrote:
Hi all,

I posted this over in alt.hvac a couple of weeks ago and didn't get
much help.
Just a bunch of smart ass answers so I thought I'd try it here.

You're not the first person to have that experience. :-)

My house is heated with hot water baseboard radiators.

www.heating-help.com is a *much* friendlier and more useful forum than
alt.hvac.

The hot water
is supplied by a boiler furnace with circulation pump. The furnace
has an automatic fill valve that is kept in the off position unless
the system needs water. It is them manually opened until proper
pressure is achieved. The burner comes on at about 150 degrees and
goes out at 160 degrees. I try to maintain about 18psi at 160 degrees
system pressure. The safety blow valve is set to blow at 35psi. It
has an air purge valve at the top of furnace just below the floor
above it (about 10 feet from basement floor).
The air purge valve is new and so is the expansion tank. The
expansion tank pressure seems to match the boiler pressure.

All sounds good so far.

Here's the problem. Every couple of days the system pressure has
dropped to about 10 or 11 psi at 160 degrees.

You have a leak somewhere.

This effects the
efficiency of both the radiator heat as well as the potable hot water
(which is heated by the boiler).
I open the fill valve, purge the air

Proof that you have a leak. Air can't get in if water can't get out.

and close it all back up at 20psi or so
at 160 degrees. All is well for another couple of days until the
pressure is back down and I repeat the process.

I don't see any leaks,

That pressure must be going somewhere. You have a leak. You just haven't found
it yet.

no water dripping from ceilings or pooling
anywhere that I can see.

That's good...

One room of the house is a concrete slab
floor (converted carport). It has heating pipe within the concrete
slab.

... but that's bad. That's where your leak is, I'm afraid.

I keep adding water and purging and the pressure keeps dropping. It's
an endless cycle.
What could cause the pressure to keep dropping?
I'm out of ideas.

Do you have any way of shutting off the water flow to the room on the slab?
The hot water system in my house has multiple heating zones, with
thermostatically controlled zone valves to control water flow into each zone.
If yours is set up similarly, closing the zone valve to that room, while
operating the system to heat the rest of the house, would help indicate where
the problem is. However, even without doing that test, I think it's a pretty
good bet that's where your leak is: in the slab.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

On Jun 8, 9:40 am, (Doug Miller) wrote:
In article . com, coustanis wrote:

Hi all,

I posted this over in alt.hvac a couple of weeks ago and didn't get
much help.
Just a bunch of smart ass answers so I thought I'd try it here.

You're not the first person to have that experience. :-)



My house is heated with hot water baseboard radiators.

www.heating-help.comis a *much* friendlier and more useful forum than
alt.hvac.

The hot water

is supplied by a boiler furnace with circulation pump. The furnace
has an automatic fill valve that is kept in the off position unless
the system needs water. It is them manually opened until proper
pressure is achieved. The burner comes on at about 150 degrees and
goes out at 160 degrees. I try to maintain about 18psi at 160 degrees
system pressure. The safety blow valve is set to blow at 35psi. It
has an air purge valve at the top of furnace just below the floor
above it (about 10 feet from basement floor).
The air purge valve is new and so is the expansion tank. The
expansion tank pressure seems to match the boiler pressure.

All sounds good so far.



Here's the problem. Every couple of days the system pressure has
dropped to about 10 or 11 psi at 160 degrees.

You have a leak somewhere.

This effects the
efficiency of both the radiator heat as well as the potable hot water
(which is heated by the boiler).
I open the fill valve, purge the air

Proof that you have a leak. Air can't get in if water can't get out.

and close it all back up at 20psi or so
at 160 degrees. All is well for another couple of days until the
pressure is back down and I repeat the process.

I don't see any leaks,

That pressure must be going somewhere. You have a leak. You just haven't found
it yet.

no water dripping from ceilings or pooling
anywhere that I can see.

That's good...

One room of the house is a concrete slab
floor (converted carport). It has heating pipe within the concrete
slab.

.. but that's bad. That's where your leak is, I'm afraid.



I keep adding water and purging and the pressure keeps dropping. It's
an endless cycle.
What could cause the pressure to keep dropping?
I'm out of ideas.

Do you have any way of shutting off the water flow to the room on the slab?
The hot water system in my house has multiple heating zones, with
thermostatically controlled zone valves to control water flow into each zone.
If yours is set up similarly, closing the zone valve to that room, while
operating the system to heat the rest of the house, would help indicate where
the problem is. However, even without doing that test, I think it's a pretty
good bet that's where your leak is: in the slab.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

No but I could drain the system and install valves (if I can get to
the pipe). That will break the loop, right?
I'd have to add pipe across to complete the circuit?

In article .com, coustanis wrote:

No but I could drain the system and install valves (if I can get to
the pipe). That will break the loop, right?
I'd have to add pipe across to complete the circuit?

No way for me to answer that without seeing how your existing pipes are laid
out. As long as there is at least one loop *somewhere* that the circulator can
pump water through, it doesn't necessarily have to bypass that room.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

On Jun 8, 9:40 am, (Doug Miller) wrote:
In article . com, coustanis wrote:


Here's the problem. Every couple of days the system pressure has
dropped to about 10 or 11 psi at 160 degrees.

You have a leak somewhere.


Not necessarily

If the expansion tank doesn't have a bladder to keep the air from
contacting the water you can develop an air problem.
http://www.bellgossett.com/Press/BG-proper.asp

I agree a leak is the most likely cause but it could be other things.
Rich Trethewey explained a way the layout of a system can cause this
problem on Ask TOH but I can't find it online.

In article .com, RayV wrote:
On Jun 8, 9:40 am, (Doug Miller) wrote:
In article . com, coustanis
wrote:


Here's the problem. Every couple of days the system pressure has
dropped to about 10 or 11 psi at 160 degrees.

You have a leak somewhere.


Not necessarily

If the expansion tank doesn't have a bladder to keep the air from
contacting the water you can develop an air problem.

No, that's not his problem. He says he has to keep purging air from the
system. That's unambiguous: he has a leak. Air can't get in, unless water's
getting out.

Further, if the problem were simply air dissolving into the system from a
non-bladder-type expansion tank, eventually that tank would become
waterlogged. Everything the OP has written indicates that has not happened.

He has a leak.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

On Jun 8, 10:59 am, RayV wrote:
On Jun 8, 9:40 am, (Doug Miller) wrote:

In article . com, coustanis wrote:

Here's the problem. Every couple of days the system pressure has
dropped to about 10 or 11 psi at 160 degrees.

You have a leak somewhere.

Not necessarily

If the expansion tank doesn't have a bladder to keep the air from
contacting the water you can develop an air problem.http://www.bellgossett.com/Press/BG-proper.asp

I agree a leak is the most likely cause but it could be other things.
Rich Trethewey explained a way the layout of a system can cause this
problem on Ask TOH but I can't find it online.

leave it at 10 psi cold, you only need more if top floor radiators are
cold, I have a 3 story boiler is 12lb cold.

On Jun 8, 8:47?am, coustanis wrote:
Hi all,

I posted this over in alt.hvac a couple of weeks ago and didn't get
much help.
Just a bunch of smart ass answers so I thought I'd try it here.

My house is heated with hot water baseboard radiators. The hot water
is supplied by a boiler furnace with circulation pump. The furnace
has an automatic fill valve that is kept in the off position unless
the system needs water. It is them manually opened until proper
pressure is achieved. The burner comes on at about 150 degrees and
goes out at 160 degrees. I try to maintain about 18psi at 160 degrees
system pressure. The safety blow valve is set to blow at 35psi. It
has an air purge valve at the top of furnace just below the floor
above it (about 10 feet from basement floor).
The air purge valve is new and so is the expansion tank. The
expansion tank pressure seems to match the boiler pressure.

Here's the problem. Every couple of days the system pressure has
dropped to about 10 or 11 psi at 160 degrees. This effects the
efficiency of both the radiator heat as well as the potable hot water
(which is heated by the boiler).
I open the fill valve, purge the air and close it all back up at 20psi
or so
at 160 degrees. All is well for another couple of days until the
pressure is back down and I repeat the process.

I don't see any leaks, no water dripping from ceilings or pooling
anywhere that I can see. One room of the house is a concrete slab
floor (converted carport). It has heating pipe within the concrete
slab.

I keep adding water and purging and the pressure keeps dropping. It's
an endless cycle.
What could cause the pressure to
keep dropping?
I'm out of ideas.

Thanks in advance,

Is this a troll post? Your hot water is heated by this unit, you keep
the "automatic" fill valve closed, and you can't figure why the
pressure is dropping. You need to stop taking those hot showers,
man , this is SUMMER. Crank up the heat and enjoy an ice-cold shower!

On Jun 8, 10:16?am, Sev wrote:
On Jun 8, 8:47?am, coustanis wrote:





Hi all,

I posted this over in alt.hvac a couple of weeks ago and didn't get
much help.
Just a bunch of smart ass answers so I thought I'd try it here.

My house is heated with hot water baseboard radiators. The hot water
is supplied by a boiler furnace with circulation pump. The furnace
has an automatic fill valve that is kept in the off position unless
the system needs water. It is them manually opened until proper
pressure is achieved. The burner comes on at about 150 degrees and
goes out at 160 degrees. I try to maintain about 18psi at 160 degrees
system pressure. The safety blow valve is set to blow at 35psi. It
has an air purge valve at the top of furnace just below the floor
above it (about 10 feet from basement floor).
The air purge valve is new and so is the expansion tank. The
expansion tank pressure seems to match the boiler pressure.

Here's the problem. Every couple of days the system pressure has
dropped to about 10 or 11 psi at 160 degrees. This effects the
efficiency of both the radiator heat as well as the potable hot water
(which is heated by the boiler).
I open the fill valve, purge the air and close it all back up at 20psi
or so
at 160 degrees. All is well for another couple of days until the
pressure is back down and I repeat the process.

I don't see any leaks, no water dripping from ceilings or pooling
anywhere that I can see. One room of the house is a concrete slab
floor (converted carport). It has heating pipe within the concrete
slab.

I keep adding water and purging and the pressure keeps dropping. It's
an endless cycle.
What could cause the pressure to
keep dropping?
I'm out of ideas.

Thanks in advance,

Is this a troll post? Your hot water is heated by this unit, you keep
the "automatic" fill valve closed, and you can't figure why the
pressure is dropping. You need to stop taking those hot showers,
man , this is SUMMER. Crank up the heat and enjoy an ice-cold shower!- Hide quoted text -

- Show quoted text -

On second thought, this has to be a separate loop, so excuse me-
still, auto fill valve should be open. But yeah, must be leak some
place.

On Jun 8, 10:21 am, Sev wrote:
On Jun 8, 10:16?am, Sev wrote:



On Jun 8, 8:47?am, coustanis wrote:

Hi all,

I posted this over in alt.hvac a couple of weeks ago and didn't get
much help.
Just a bunch of smart ass answers so I thought I'd try it here.

My house is heated with hot water baseboard radiators. The hot water
is supplied by a boiler furnace with circulation pump. The furnace
has an automatic fill valve that is kept in the off position unless
the system needs water. It is them manually opened until proper
pressure is achieved. The burner comes on at about 150 degrees and
goes out at 160 degrees. I try to maintain about 18psi at 160 degrees
system pressure. The safety blow valve is set to blow at 35psi. It
has an air purge valve at the top of furnace just below the floor
above it (about 10 feet from basement floor).
The air purge valve is new and so is the expansion tank. The
expansion tank pressure seems to match the boiler pressure.

Here's the problem. Every couple of days the system pressure has
dropped to about 10 or 11 psi at 160 degrees. This effects the
efficiency of both the radiator heat as well as the potable hot water
(which is heated by the boiler).
I open the fill valve, purge the air and close it all back up at 20psi
or so
at 160 degrees. All is well for another couple of days until the
pressure is back down and I repeat the process.

I don't see any leaks, no water dripping from ceilings or pooling
anywhere that I can see. One room of the house is a concrete slab
floor (converted carport). It has heating pipe within the concrete
slab.

I keep adding water and purging and the pressure keeps dropping. It's
an endless cycle.
What could cause the pressure to
keep dropping?
I'm out of ideas.

Thanks in advance,

Is this a troll post? Your hot water is heated by this unit, you keep
the "automatic" fill valve closed, and you can't figure why the
pressure is dropping. You need to stop taking those hot showers,
man , this is SUMMER. Crank up the heat and enjoy an ice-cold shower!- Hide quoted text -

- Show quoted text -

On second thought, this has to be a separate loop, so excuse me-
still, auto fill valve should be open. But yeah, must be leak some
place.

Oops. I responded to your first post before I read this. I bet it's
in the slab. I just had the wood floor put in last year. CRAP.
The water must be going down under the slab because I don't see water
anywhere. Do you suppose it's washing the dirt out from under the
concrete?

In article . com, coustanis wrote:

Oops. I responded to your first post before I read this. I bet it's
in the slab. I just had the wood floor put in last year. CRAP.
The water must be going down under the slab because I don't see water
anywhere. Do you suppose it's washing the dirt out from under the
concrete?

Yep.

Unfortunately.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

On Jun 8, 11:15 am, (Doug Miller) wrote:
In article . com, coustanis wrote:

Oops. I responded to your first post before I read this. I bet it's
in the slab. I just had the wood floor put in last year. CRAP.
The water must be going down under the slab because I don't see water
anywhere. Do you suppose it's washing the dirt out from under the
concrete?

Yep.

Unfortunately.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

I wonder if my homeowners insurance will cover it. Then they can
raise my rates or drop me.

In article . com, Sev wrote:

On second thought, this has to be a separate loop, so excuse me-
still, auto fill valve should be open. But yeah, must be leak some
place.

No, the auto fill valve should *not* be open. Multiple reasons:

1) Doing so continuously exposes the pressure regulator on the fill side to
the full pressure of the water supply, and can shorten its life.

2) With the auto fill valve open, hidden leaks may go undetected for a long
time, as the lost water is continously replaced.

3) Any failure (such as a ruptured pipe or valve) will result in continous
flow of water until the problem is detected and the fill valve closed.

The OP is operating his system correctly, by opening the fill valve only when
he knows he needs to fill the system.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

On Fri, 08 Jun 2007 15:05:47 GMT, (Doug Miller)
wrote:

In article . com, Sev wrote:

On second thought, this has to be a separate loop, so excuse me-
still, auto fill valve should be open. But yeah, must be leak some
place.

No, the auto fill valve should *not* be open. Multiple reasons:

1) Doing so continuously exposes the pressure regulator on the fill side to
the full pressure of the water supply, and can shorten its life.

2) With the auto fill valve open, hidden leaks may go undetected for a long
time, as the lost water is continously replaced.

3) Any failure (such as a ruptured pipe or valve) will result in continous
flow of water until the problem is detected and the fill valve closed.

The OP is operating his system correctly, by opening the fill valve only when
he knows he needs to fill the system.

I"m sure you're right, based on all your reasosn, but why do they
still call it an AUTO fill valve? Isn't that likely to confuse lots
of people into leaving it open, with just the bad results you list?

On Jun 8, 3:23 pm, mm wrote:
On Fri, 08 Jun 2007 15:05:47 GMT, (Doug Miller)
wrote:



In article . com, Sev wrote:

On second thought, this has to be a separate loop, so excuse me-
still, auto fill valve should be open. But yeah, must be leak some
place.

No, the auto fill valve should *not* be open. Multiple reasons:

1) Doing so continuously exposes the pressure regulator on the fill side to
the full pressure of the water supply, and can shorten its life.

2) With the auto fill valve open, hidden leaks may go undetected for a long
time, as the lost water is continously replaced.

3) Any failure (such as a ruptured pipe or valve) will result in continous
flow of water until the problem is detected and the fill valve closed.

The OP is operating his system correctly, by opening the fill valve only when
he knows he needs to fill the system.

I"m sure you're right, based on all your reasosn, but why do they
still call it an AUTO fill valve? Isn't that likely to confuse lots
of people into leaving it open, with just the bad results you list?

The B & G fill valve that I see on most installations is an auto fill
valve with a lever for fast fill, and a screw to adjust the fill
pressure. I would agree that the "fast-fill" lever shouldn't be left
open, but would disagree that the water supply leading to the fill
valve should be left off. Why even have it in place if it is only
used to fill the boiler manually when the pressure is low. It would
be nearly the same amount of effort to open a valve while watching the
gauge on the boiler when you needed to fill it.

Of course, if I posted this at alt.hvac, they would be laughing their
collective asses off, whether I was right or wrong.

JK

On Jun 8, 10:16 am, Sev wrote:
On Jun 8, 8:47?am, coustanis wrote:



Hi all,

I posted this over in alt.hvac a couple of weeks ago and didn't get
much help.
Just a bunch of smart ass answers so I thought I'd try it here.

My house is heated with hot water baseboard radiators. The hot water
is supplied by a boiler furnace with circulation pump. The furnace
has an automatic fill valve that is kept in the off position unless
the system needs water. It is them manually opened until proper
pressure is achieved. The burner comes on at about 150 degrees and
goes out at 160 degrees. I try to maintain about 18psi at 160 degrees
system pressure. The safety blow valve is set to blow at 35psi. It
has an air purge valve at the top of furnace just below the floor
above it (about 10 feet from basement floor).
The air purge valve is new and so is the expansion tank. The
expansion tank pressure seems to match the boiler pressure.

Here's the problem. Every couple of days the system pressure has
dropped to about 10 or 11 psi at 160 degrees. This effects the
efficiency of both the radiator heat as well as the potable hot water
(which is heated by the boiler).
I open the fill valve, purge the air and close it all back up at 20psi
or so
at 160 degrees. All is well for another couple of days until the
pressure is back down and I repeat the process.

I don't see any leaks, no water dripping from ceilings or pooling
anywhere that I can see. One room of the house is a concrete slab
floor (converted carport). It has heating pipe within the concrete
slab.

I keep adding water and purging and the pressure keeps dropping. It's
an endless cycle.
What could cause the pressure to
keep dropping?
I'm out of ideas.

Thanks in advance,

Is this a troll post? Your hot water is heated by this unit, you keep
the "automatic" fill valve closed, and you can't figure why the
pressure is dropping. You need to stop taking those hot showers,
man , this is SUMMER. Crank up the heat and enjoy an ice-cold shower!

No, this is not a troll post. I don't understand your response unless
you are thinking that the same water that circulates through the rads
is
the same hot water that comes out of the tap. That is not the case.
The boiler has a coil of copper pipe running through it that heats the
potable water within.
Two entirely separate circuits.

"coustanis" wrote in message
The air purge valve is new and so is the expansion tank. The
expansion tank pressure seems to match the boiler pressure.

Here's the problem. Every couple of days the system pressure has
dropped to about 10 or 11 psi at 160 degrees. This effects the
efficiency of both the radiator heat as well as the potable hot water
(which is heated by the boiler).
I open the fill valve, purge the air and close it all back up at 20psi
or so
at 160 degrees. All is well for another couple of days until the
pressure is back down and I repeat the process.

When the system cools down, the water that was expanded from heating now
shrinks and the system will suck in air through the valve on the expansion
tank. Try leaving the feed valve open and it will solve your problem.



I keep adding water and purging and the pressure keeps dropping. It's
an endless cycle.
What could cause the pressure to
keep dropping?


Expansion and contraction

In article Zugai.25$c45.13@trndny06, "Edwin Pawlowski" wrote:

"coustanis" wrote in message
The air purge valve is new and so is the expansion tank. The
expansion tank pressure seems to match the boiler pressure.

Here's the problem. Every couple of days the system pressure has
dropped to about 10 or 11 psi at 160 degrees. This effects the
efficiency of both the radiator heat as well as the potable hot water
(which is heated by the boiler).
I open the fill valve, purge the air and close it all back up at 20psi
or so
at 160 degrees. All is well for another couple of days until the
pressure is back down and I repeat the process.

When the system cools down, the water that was expanded from heating now
shrinks and the system will suck in air through the valve on the expansion
tank. Try leaving the feed valve open and it will solve your problem.

That is not correct. Air purge valves are one-way. They let air out, but not
in.



I keep adding water and purging and the pressure keeps dropping. It's
an endless cycle.
What could cause the pressure to
keep dropping?


Expansion and contraction

Nope. He has a leak.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

"Doug Miller" wrote in message news:Gbhai.713
When the system cools down, the water that was expanded from heating now
shrinks and the system will suck in air through the valve on the
expansion
tank. Try leaving the feed valve open and it will solve your problem.

That is not correct. Air purge valves are one-way. They let air out, but
not
in.



I keep adding water and purging and the pressure keeps dropping. It's
an endless cycle.
What could cause the pressure to
keep dropping?


Expansion and contraction

Nope. He has a leak.

Maybe he does, but I don't and if I close the valve I have the same problem.
It has been open for the past 25 years and if I had a leak, I'd guess I'd
have found it by now.

Edwin Pawlowski wrote:
"Doug Miller" wrote in message news:Gbhai.713
When the system cools down, the water that was expanded from heating now
shrinks and the system will suck in air through the valve on the
expansion
tank. Try leaving the feed valve open and it will solve your problem.
That is not correct. Air purge valves are one-way. They let air out, but
not
in.


I keep adding water and purging and the pressure keeps dropping. It's
an endless cycle.
What could cause the pressure to
keep dropping?

Expansion and contraction
Nope. He has a leak.

Maybe he does, but I don't and if I close the valve I have the same problem.
It has been open for the past 25 years and if I had a leak, I'd guess I'd
have found it by now.


I've not followed the whole thread, but if OP continues to add water
indefinitely and pressure continues to drop and never recovers, the
system _eventually_ would have to fill solid if the water isn't going
somewhere...it is, after all a finite volume.

--

In article 3Yhai.354$4t5.62@trndny07, "Edwin Pawlowski" wrote:

"Doug Miller" wrote in message news:Gbhai.713
When the system cools down, the water that was expanded from heating now
shrinks and the system will suck in air through the valve on the
expansion
tank. Try leaving the feed valve open and it will solve your problem.

That is not correct. Air purge valves are one-way. They let air out, but
not
in.



I keep adding water and purging and the pressure keeps dropping. It's
an endless cycle.
What could cause the pressure to
keep dropping?


Expansion and contraction

Nope. He has a leak.

Maybe he does, but I don't and if I close the valve I have the same problem.

*Exactly* the same problem? Including the need to repeatedly purge air from
the system?

It has been open for the past 25 years and if I had a leak, I'd guess I'd
have found it by now.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

"Doug Miller" wrote in message
Maybe he does, but I don't and if I close the valve I have the same
problem.

*Exactly* the same problem? Including the need to repeatedly purge air
from
the system?

I did say "the same problem" didn't I?

I had a problem this past winder with the packing nut on the feed valve. I
didn't get around to fixing it for some time, but it did not leak when
turned off. The noise from air in the system was very loud, especially
after being off all night and going back on first thing in the morning. It
woke me before the alarm went off. I finally replaced the valve, left it
open, problem went away once the air self purged. There is a valve on top
of the Extrol expansion tank for this purpose.

Sorry if my real life factual situation differs from your opinion. The feed
valve is still open, but I'll probably close it until heating seasons starts
again. Then it will be open, same as it has been for the 29 years this
house has existed.
--
Ed
http://pages.cthome.net/edhome/