Hi,
I installed an Albion Mainsflow thermal store about 5 years ago. It's
this type here to save explaining how it works:
http://www.albionwaterheaters.com/pd.../mainsflow.pdf
It's the direct contractor version on page 3 where the store has a float
valve at the top and acts as the feed and expansion tank for the
boiler/radiators as well as providing hot water.
The problem is its been overflowing (about half a bucket per day). It's
not the float valve as I've cut and capped the pipe going to it, so that
only leaves the DHW coil. I connected a pressure tester to the coil and
didn't get any bubbles or noticeable drop in pressure, but there's no
other way for water to get into the store.
So I'm left with two options. Either replace the coil with an external
plate heat exchanger, pump and flow switch. This'll cost about £250 in
parts to do. The downside is if the copper coil is failing, will the
cylinder itself go in time? If so, it might be better to replace the
whole thing, maybe going for a more conventional unvented cylinder,
which are pretty cheap (e.g. Vaillant Unistor 155 is less than £600 +
fitting). I could also switch to a sealed system for the boiler/rads.
But unvented cylinders aren't DIY (how much would a pro charge do you
think to put one in?).
Any advice appreciated.
Cheers, Antony.

On Nov 6, 12:23*pm, Antony Jones wrote:
Hi,
I installed an Albion Mainsflow thermal store about 5 years ago. It's
this type here to save explaining how it works:http://www.albionwaterheaters.com/pd.../mainsflow.pdf
It's the direct contractor version on page 3 where the store has a float
valve at the top and acts as the feed and expansion tank for the
boiler/radiators as well as providing hot water.
The problem is its been overflowing (about half a bucket per day). It's
not the float valve as I've cut and capped the pipe going to it, so that
only leaves the DHW coil. I connected a pressure tester to the coil and
didn't get any bubbles or noticeable drop in pressure, but there's no
other way for water to get into the store.
So I'm left with two options. Either replace the coil with an external
plate heat exchanger, pump and flow switch. This'll cost about £250 in
parts to do. The downside is if the copper coil is failing, will the
cylinder itself go in time? If so, it might be better to replace the
whole thing, maybe going for a more conventional unvented cylinder,
which are pretty cheap (e.g. Vaillant Unistor 155 is less than £600 +
fitting). I could also switch to a sealed system for the boiler/rads.
But unvented cylinders aren't DIY (how much would a pro charge do you
think to put one in?).
Any advice appreciated.
Cheers, Antony.

A pressure test can give a false reading if one of the isloating
valves is passing. It best to do the test with the pipework
completely disconnected.
The other way is to disconnect the coil and see if you get drips
coming out of it that don't go away after a while, ie water leaking
out of the storage tank into the coil.
It does sound like the coil has failed.
It might not be corrosion, sometimes they crack if there is a stress
concentration point due to thermal movement. If you can get the coil
out it may be repairable or replaceable if there are spares to be had.
Even make one if it's just a bit of pipe.

On Nov 6, 4:37*pm, harry wrote:
On Nov 6, 12:23*pm, Antony Jones wrote:





Hi,
I installed an Albion Mainsflow thermal store about 5 years ago. It's
this type here to save explaining how it works:http://www.albionwaterheaters.com/pd.../mainsflow.pdf
It's the direct contractor version on page 3 where the store has a float
valve at the top and acts as the feed and expansion tank for the
boiler/radiators as well as providing hot water.
The problem is its been overflowing (about half a bucket per day). It's
not the float valve as I've cut and capped the pipe going to it, so that
only leaves the DHW coil. I connected a pressure tester to the coil and
didn't get any bubbles or noticeable drop in pressure, but there's no
other way for water to get into the store.
So I'm left with two options. Either replace the coil with an external
plate heat exchanger, pump and flow switch. This'll cost about £250 in
parts to do. The downside is if the copper coil is failing, will the
cylinder itself go in time? If so, it might be better to replace the
whole thing, maybe going for a more conventional unvented cylinder,
which are pretty cheap (e.g. Vaillant Unistor 155 is less than £600 +
fitting). I could also switch to a sealed system for the boiler/rads.
But unvented cylinders aren't DIY (how much would a pro charge do you
think to put one in?).
Any advice appreciated.
Cheers, Antony.

A pressure test can give a false reading if one of the isloating
valves is passing. *It best to do the test with the pipework
completely disconnected.
The other way is to disconnect the coil and see if you get drips
coming out of it that don't go away after a while, ie water leaking
out of the storage tank into the coil.
It does sound like the coil has failed.
*It might not be corrosion, sometimes they crack if there is a stress
concentration point due to thermal movement. If you can get the coil
out it may be repairable or replaceable if there are spares to be had.
Even make one if it's just a bit of pipe.- Hide quoted text -

- Show quoted text -

Just another thought. I once saw a similar problem caused by a fauly
mixer tap. Cold water was transfering into the hot system due to a
fault on this mixer tap.
Also check out if water is running into your header tank for the
heating system. If what you suspect is true, it would have to be.

On Nov 6, 4:37*pm, harry wrote:
On Nov 6, 12:23*pm, Antony Jones wrote:





Hi,
I installed an Albion Mainsflow thermal store about 5 years ago. It's
this type here to save explaining how it works:http://www.albionwaterheaters.com/pd.../mainsflow.pdf
It's the direct contractor version on page 3 where the store has a float
valve at the top and acts as the feed and expansion tank for the
boiler/radiators as well as providing hot water.
The problem is its been overflowing (about half a bucket per day). It's
not the float valve as I've cut and capped the pipe going to it, so that
only leaves the DHW coil. I connected a pressure tester to the coil and
didn't get any bubbles or noticeable drop in pressure, but there's no
other way for water to get into the store.
So I'm left with two options. Either replace the coil with an external
plate heat exchanger, pump and flow switch. This'll cost about £250 in
parts to do. The downside is if the copper coil is failing, will the
cylinder itself go in time? If so, it might be better to replace the
whole thing, maybe going for a more conventional unvented cylinder,
which are pretty cheap (e.g. Vaillant Unistor 155 is less than £600 +
fitting). I could also switch to a sealed system for the boiler/rads.
But unvented cylinders aren't DIY (how much would a pro charge do you
think to put one in?).
Any advice appreciated.
Cheers, Antony.

A pressure test can give a false reading if one of the isloating
valves is passing. *It best to do the test with the pipework
completely disconnected.
The other way is to disconnect the coil and see if you get drips
coming out of it that don't go away after a while, ie water leaking
out of the storage tank into the coil.
It does sound like the coil has failed.
*It might not be corrosion, sometimes they crack if there is a stress
concentration point due to thermal movement. If you can get the coil
out it may be repairable or replaceable if there are spares to be had.
Even make one if it's just a bit of pipe.- Hide quoted text -

- Show quoted text -

Or, a faulty mixer valve on a shower. Seen that one too.

On Nov 6, 4:37*pm, harry wrote:
On Nov 6, 12:23*pm, Antony Jones wrote:





Hi,
I installed an Albion Mainsflow thermal store about 5 years ago. It's
this type here to save explaining how it works:http://www.albionwaterheaters.com/pd.../mainsflow.pdf
It's the direct contractor version on page 3 where the store has a float
valve at the top and acts as the feed and expansion tank for the
boiler/radiators as well as providing hot water.
The problem is its been overflowing (about half a bucket per day). It's
not the float valve as I've cut and capped the pipe going to it, so that
only leaves the DHW coil. I connected a pressure tester to the coil and
didn't get any bubbles or noticeable drop in pressure, but there's no
other way for water to get into the store.
So I'm left with two options. Either replace the coil with an external
plate heat exchanger, pump and flow switch. This'll cost about £250 in
parts to do. The downside is if the copper coil is failing, will the
cylinder itself go in time? If so, it might be better to replace the
whole thing, maybe going for a more conventional unvented cylinder,
which are pretty cheap (e.g. Vaillant Unistor 155 is less than £600 +
fitting). I could also switch to a sealed system for the boiler/rads.
But unvented cylinders aren't DIY (how much would a pro charge do you
think to put one in?).
Any advice appreciated.
Cheers, Antony.

A pressure test can give a false reading if one of the isloating
valves is passing. *It best to do the test with the pipework
completely disconnected.
The other way is to disconnect the coil and see if you get drips
coming out of it that don't go away after a while, ie water leaking
out of the storage tank into the coil.
It does sound like the coil has failed.
*It might not be corrosion, sometimes they crack if there is a stress
concentration point due to thermal movement. If you can get the coil
out it may be repairable or replaceable if there are spares to be had.
Even make one if it's just a bit of pipe.- Hide quoted text -

- Show quoted text -

Or a faulty mixer valve on a shower. Some have non-return valves that
can jam open. Seen that one too.

On 06/11/2010 16:37, harry wrote:
On Nov 6, 12:23 pm, Antony wrote:
Hi,
I installed an Albion Mainsflow thermal store about 5 years ago. It's
this type here to save explaining how it works:http://www.albionwaterheaters.com/pd.../mainsflow.pdf
It's the direct contractor version on page 3 where the store has a float
valve at the top and acts as the feed and expansion tank for the
boiler/radiators as well as providing hot water.
The problem is its been overflowing (about half a bucket per day). It's
not the float valve as I've cut and capped the pipe going to it, so that
only leaves the DHW coil. I connected a pressure tester to the coil and
didn't get any bubbles or noticeable drop in pressure, but there's no
other way for water to get into the store.
So I'm left with two options. Either replace the coil with an external
plate heat exchanger, pump and flow switch. This'll cost about £250 in
parts to do. The downside is if the copper coil is failing, will the
cylinder itself go in time? If so, it might be better to replace the
whole thing, maybe going for a more conventional unvented cylinder,
which are pretty cheap (e.g. Vaillant Unistor 155 is less than £600 +
fitting). I could also switch to a sealed system for the boiler/rads.
But unvented cylinders aren't DIY (how much would a pro charge do you
think to put one in?).
Any advice appreciated.
Cheers, Antony.

A pressure test can give a false reading if one of the isloating
valves is passing. It best to do the test with the pipework
completely disconnected.
The other way is to disconnect the coil and see if you get drips
coming out of it that don't go away after a while, ie water leaking
out of the storage tank into the coil.
It does sound like the coil has failed.
It might not be corrosion, sometimes they crack if there is a stress
concentration point due to thermal movement. If you can get the coil
out it may be repairable or replaceable if there are spares to be had.
Even make one if it's just a bit of pipe.

I disconnected the pipework both sides of the coil, so that just left
the blending valve and expansion vessel in the circuit I was testing.
The expansion vessel could be confusing things, of course.

The internal coil is made of 4 10mm pipes bunched together, so the pipes
could have cracked or pin-holed. Or the soldered joints into the 22mm
feed pipes could be failing. I'd prefer a crack to corrosion as that
would give me more confidence in keeping the store.
(see http://img709.imageshack.us/img709/2900/p1130267.jpg and
http://img3.imageshack.us/img3/1084/p1130262k.jpg which I took last time
I drained the store down).

But I have had other problems with 2 radiators pin holing despite
inhibitor. Which makes me worried about my water being more aggressive
than normal. It doesn't help having the leak as that is slowly diluting
the inhibitor, of course.

Cheers,
Antony.

On Nov 6, 5:36*pm, Antony Jones wrote:
On 06/11/2010 16:37, harry wrote:



On Nov 6, 12:23 pm, Antony *wrote:
Hi,
I installed an Albion Mainsflow thermal store about 5 years ago. It's
this type here to save explaining how it works:http://www.albionwaterheaters.com/pd.../mainsflow.pdf
It's the direct contractor version on page 3 where the store has a float
valve at the top and acts as the feed and expansion tank for the
boiler/radiators as well as providing hot water.
The problem is its been overflowing (about half a bucket per day). It's
not the float valve as I've cut and capped the pipe going to it, so that
only leaves the DHW coil. I connected a pressure tester to the coil and
didn't get any bubbles or noticeable drop in pressure, but there's no
other way for water to get into the store.
So I'm left with two options. Either replace the coil with an external
plate heat exchanger, pump and flow switch. This'll cost about £250 in
parts to do. The downside is if the copper coil is failing, will the
cylinder itself go in time? If so, it might be better to replace the
whole thing, maybe going for a more conventional unvented cylinder,
which are pretty cheap (e.g. Vaillant Unistor 155 is less than £600 +
fitting). I could also switch to a sealed system for the boiler/rads.
But unvented cylinders aren't DIY (how much would a pro charge do you
think to put one in?).
Any advice appreciated.
Cheers, Antony.

A pressure test can give a false reading if one of the isloating
valves is passing. *It best to do the test with the pipework
completely disconnected.
The other way is to disconnect the coil and see if you get drips
coming out of it that don't go away after a while, ie water leaking
out of the storage tank into the coil.
It does sound like the coil has failed.
* It might not be corrosion, sometimes they crack if there is a stress
concentration point due to thermal movement. If you can get the coil
out it may be repairable or replaceable if there are spares to be had.
Even make one if it's just a bit of pipe.

I disconnected the pipework both sides of the coil, so that just left
the blending valve and expansion vessel in the circuit I was testing.
The expansion vessel could be confusing things, of course.

The internal coil is made of 4 10mm pipes bunched together, so the pipes
could have cracked or pin-holed. Or the soldered joints into the 22mm
feed pipes could be failing. I'd prefer a crack to corrosion as that
would give me more confidence in keeping the store.
(seehttp://img709.imageshack.us/img709/2900/p1130267.jpgandhttp://img3.imageshack.us/img3/1084/p1130262k.jpgwhich I took last time
I drained the store down).

But I have had other problems with 2 radiators pin holing despite
inhibitor. Which makes me worried about my water being more aggressive
than normal. It doesn't help having the leak as that is slowly diluting
the inhibitor, of course.

Cheers,
Antony.

There's always a Yorkshire sidewinder.


NT

On 06/11/2010 20:34, Tabby wrote:
Yorkshire sidewinder
I had to look that up (I actually thought you were winding me up at
first....)
Interesting. It seems Yorkshire don't make them anymore, but it's the
sort of thing that could be made on a bench.
Were you thinking of this to make my thermal store indirect so I could
convert to sealed system, or as a replacement for the DHW coil? One way
of replacing the existing DHW coil would be to drop it in through the
lid, so to speak, as I think one commercial product does (or did).
Googling around it appears NuHeat do a store where the brazed plate heat
exchanger is immersed in the store rather than sitting outside it, which
does make some sense (no heat loss to air).
Cheers,
Antony

On 06/11/2010 21:48, Antony Jones wrote:
On 06/11/2010 20:34, Tabby wrote:
Yorkshire sidewinder
I had to look that up (I actually thought you were winding me up at
first....)
Interesting. It seems Yorkshire don't make them anymore, but it's the
sort of thing that could be made on a bench.
Were you thinking of this to make my thermal store indirect so I could
convert to sealed system, or as a replacement for the DHW coil? One way
of replacing the existing DHW coil would be to drop it in through the
lid, so to speak, as I think one commercial product does (or did).
Googling around it appears NuHeat do a store where the brazed plate heat
exchanger is immersed in the store rather than sitting outside it, which
does make some sense (no heat loss to air).
Cheers,
Antony
Just to follow up my own post, it occurs to me another option to convert
my store to sealed operation would be a small plate heat exchanger (the
boiler is only 18kw). It means adding another pump, controlled by the
zone valve on the boiler-cylinder side...

But the first problem is the leaky DHW coil. Another half bucket filled
over night...