Hi, All.

Our CH is loosing pressure.
At an anoyingly slow rate.

Half a bar a week or so.

Means that every 2 weeks or so, I need to give it a quick top-up after
the boiler has locked out for under-pressure. THat involves a trip
outside ( usually in dressing-gown ) to the garage on the lower level.

I'm of the opinion that the leak rate is so low, that even with visible
pipework, it would be hard to find. WIth pipework inaccessible, I
might as well just live with it unless the leak rate becomes
substantially worse.

It's not leaking from the boiler PRV.

I've considered building an 'auto-fill' device, involving pressure and
temperature sensors, and timers. It would come on at pre-defined
times, when the system is cold, and below a lower threshold pressure. It
would open the solenoid valve untill the pressure reached an upper
pressure threshold ( or a 10-second timer times out to prevent flooding
if major leak ).

Anyone tried anything similar?

--
Ron

On 29/03/2011 22:40, Ron Lowe wrote:
Hi, All.

Our CH is loosing pressure.
At an anoyingly slow rate.

Half a bar a week or so.

Means that every 2 weeks or so, I need to give it a quick top-up after
the boiler has locked out for under-pressure. THat involves a trip
outside ( usually in dressing-gown ) to the garage on the lower level.

I'm of the opinion that the leak rate is so low, that even with visible
pipework, it would be hard to find. WIth pipework inaccessible, I might
as well just live with it unless the leak rate becomes substantially worse.

It's not leaking from the boiler PRV.

I've considered building an 'auto-fill' device, involving pressure and
temperature sensors, and timers. It would come on at pre-defined times,
when the system is cold, and below a lower threshold pressure. It would
open the solenoid valve untill the pressure reached an upper pressure
threshold ( or a 10-second timer times out to prevent flooding if major
leak ).

Anyone tried anything similar?

You could just check it every week to stop the lock-out.

On Mar 29, 10:40*pm, Ron Lowe wrote:
Hi, All.

Our CH is loosing pressure.
At an anoyingly slow rate.

Half a bar a week or so.

Means that every 2 weeks or so, I need to give it a quick top-up after
the boiler has locked out for under-pressure. * THat involves a trip
outside ( usually in dressing-gown ) to the garage on the lower level.

I'm of the opinion that the leak rate is so low, that even with visible
pipework, it would be hard to find. * WIth pipework inaccessible, I
might as well just live with it unless the leak rate becomes
substantially worse.

It's not leaking from the boiler PRV.

I've considered building an 'auto-fill' device, involving pressure and
temperature sensors, and timers. * It would come on at pre-defined
times, when the system is cold, and below a lower threshold pressure. It
would open the solenoid valve untill the pressure reached an upper
pressure threshold ( or a 10-second timer times out to prevent flooding
if major leak ).

Anyone tried anything similar?

--
Ron

Commercial pressurisation units such as you describe are already on
the market.

On 29/03/2011 22:40, Ron Lowe wrote:
Hi, All.

Our CH is loosing pressure.
At an anoyingly slow rate.

Half a bar a week or so.

Means that every 2 weeks or so, I need to give it a quick top-up after
the boiler has locked out for under-pressure. THat involves a trip
outside ( usually in dressing-gown ) to the garage on the lower level.

I'm of the opinion that the leak rate is so low, that even with visible
pipework, it would be hard to find. WIth pipework inaccessible, I might
as well just live with it unless the leak rate becomes substantially worse.

It's not leaking from the boiler PRV.

I've considered building an 'auto-fill' device, involving pressure and
temperature sensors, and timers. It would come on at pre-defined times,
when the system is cold, and below a lower threshold pressure. It would
open the solenoid valve untill the pressure reached an upper pressure
threshold ( or a 10-second timer times out to prevent flooding if major
leak ).

Anyone tried anything similar?


Aren't there some products on the market which you can add to the water
in the system to seal minor leaks?

Failing that, why not top it up more often (while fully clothed!)
without waiting for it to lock out?
--
Cheers,
Roger
____________
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checked.

In message , Roger Mills
writes
On 29/03/2011 22:40, Ron Lowe wrote:
Hi, All.

Our CH is loosing pressure.
At an anoyingly slow rate.




Aren't there some products on the market which you can add to the water
in the system to seal minor leaks?

Is there the equivalent of 'Radweld' available for CH systems? It's ages
since I've had to use it in a car*, but it does work well provided there
is no flexing where the leak is.
*Remember the good old days when car radiators all leaked (outwards) and
windscreens, doors and boots also all leaked (inwards)?
--
Ian

On 30/03/2011 13:15, Ian Jackson wrote:
In message , Roger Mills
writes
On 29/03/2011 22:40, Ron Lowe wrote:
Hi, All.

Our CH is loosing pressure.
At an anoyingly slow rate.




Aren't there some products on the market which you can add to the
water in the system to seal minor leaks?

Is there the equivalent of 'Radweld' available for CH systems? It's ages
since I've had to use it in a car*, but it does work well provided there
is no flexing where the leak is.
*Remember the good old days when car radiators all leaked (outwards) and
windscreens, doors and boots also all leaked (inwards)?


Yes, Screwfix do a variety of products by Fernox and Sentinel - such as
http://www.screwfix.com/p/sentinel-r...er-400ml/84917

Many years ago, I used some Bar's Leaks stuff intended for cars (still
seemingly available) in my then (vented) CH system, and it worked perfectly.
--
Cheers,
Roger
____________
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checked.

On Mar 29, 10:40*pm, Ron Lowe wrote:
Hi, All.

Our CH is loosing pressure.
At an anoyingly slow rate.

It's not leaking from the boiler PRV.

I've considered building an 'auto-fill' device, involving pressure....
Anyone tried anything similar?

--
Ron

The top-up water is bringing limescale and oxygen in to the system,
and will cause corrosion and sludge problems over time, so ideally
should be sealed; but you know that.
Check all the exposed rad valves and pipework; because you are
dreading a leak under an inaccessible floor, one tends to assume that
is where the leak is. A small leak can evaporate from hot pipes,
leaving only stains behind.

The only means of legally connecting the mains water to a heating
system is through a reduced pressure zone valve, the appropriate
device to prevent back-siphonage of the fluid (Cat 3?) into the water
mains. These are available commercially but are very expensive and
should be installed and commissioned by someone with the relevant
ticket. Solenoid valve gadgets with pressure switches can be done,
but not legally under the Water Regulations.

Pressurisation units have a break tank and a small 12V (usually)
pump operated by start and stop pressure switches. I have one that I
use occasionally for anti-freeze and stuff; useful (to me) does
exactly what it says on the box and all legal.

You could put in an additional pressure vessel(s) to give a longer
interval between top-up and shut down.

In message , Ron Lowe writes
Hi, All.

Our CH is loosing pressure.
At an anoyingly slow rate.

Half a bar a week or so.

Means that every 2 weeks or so, I need to give it a quick top-up after
the boiler has locked out for under-pressure. THat involves a trip
outside ( usually in dressing-gown ) to the garage on the lower level.

I'm of the opinion that the leak rate is so low, that even with visible
pipework, it would be hard to find. WIth pipework inaccessible, I
might as well just live with it unless the leak rate becomes
substantially worse.

It's not leaking from the boiler PRV.

I've considered building an 'auto-fill' device, involving pressure and
temperature sensors, and timers. It would come on at pre-defined
times, when the system is cold, and below a lower threshold pressure.
It would open the solenoid valve untill the pressure reached an upper
pressure threshold ( or a 10-second timer times out to prevent flooding
if major leak ).

Anyone tried anything similar?

Sounds a lot of faffing about for something you could do maybe once a
week manually. Are you going to get it to deliver a measured amount of
inhibitor at the same time ?



--
geoff

On 30/03/2011 23:35, geoff wrote:

I've considered building an 'auto-fill' device, involving pressure and
temperature sensors, and timers. It would come on at pre-defined
times, when the system is cold, and below a lower threshold pressure.
It would open the solenoid valve untill the pressure reached an upper
pressure threshold ( or a 10-second timer times out to prevent
flooding if major leak ).

Anyone tried anything similar?

Sounds a lot of faffing about for something you could do maybe once a
week manually.

Correct.
But usually at inconvenient times because I've forgotten.

Are you going to get it to deliver a measured amount of
inhibitor at the same time ?


Precisely the same amount as the manual re-charge.


The volumes involved are very small.
The dilution will occour either way, but I'm not over-concerned in the
medium-term. I may manually add some every year or so.


I may look into some of the rad-weld type products ( ISTR that egg-based
solutions used to exist... )


--
Ron

In message , Ron Lowe writes



I may look into some of the rad-weld type products ( ISTR that
egg-based solutions used to exist... )

Although I never tried it, I have always understood that egg white was
one of the olde tyme cures.

I did try mustard powder. Big mistake. Not only did it not work, but the
car stank of mustard for months and months.

If I were you, I'd try one of Roger Mills's suggestions!
http://www.screwfix.com/p/sentinel-rapid-dose-leak-sealer-400ml/84917

--
Ian

In article ,
Ron Lowe writes:
Hi, All.

Our CH is loosing pressure.
At an anoyingly slow rate.

Half a bar a week or so.

Means that every 2 weeks or so, I need to give it a quick top-up after
the boiler has locked out for under-pressure. THat involves a trip
outside ( usually in dressing-gown ) to the garage on the lower level.

I'm of the opinion that the leak rate is so low, that even with visible
pipework, it would be hard to find. WIth pipework inaccessible, I
might as well just live with it unless the leak rate becomes
substantially worse.

Wait until the heating is off and the system cold.
Then pressurize it up to it's normal hot pressure with cold water.
This will cause it to leak at its normal leak rate, but being cold,
the leak isn't going to dry up and may then be locatable.

Actually, this is something I do every few years as part of the
system servicing. I usually find a couple of radiator stop valve
shafts which seep and I swap them out, even though the leak isn't
yet bad enough to emerge from under the cap.

The other place I've found a leak is the O-ring seal on a radiator
bleeding plug, but that was just after I had removed and refitted
it to add inhibitor - it didn't seal after refitting.

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

On 31/03/2011 20:54, Andrew Gabriel wrote:
In ,
Ron writes:
Hi, All.

Our CH is loosing pressure.
At an anoyingly slow rate.

Half a bar a week or so.

Means that every 2 weeks or so, I need to give it a quick top-up after
the boiler has locked out for under-pressure. THat involves a trip
outside ( usually in dressing-gown ) to the garage on the lower level.

I'm of the opinion that the leak rate is so low, that even with visible
pipework, it would be hard to find. WIth pipework inaccessible, I
might as well just live with it unless the leak rate becomes
substantially worse.

Wait until the heating is off and the system cold.
Then pressurize it up to it's normal hot pressure with cold water.
This will cause it to leak at its normal leak rate, but being cold,
the leak isn't going to dry up and may then be locatable.

Well yes, if the pipework was visible!

It's underneath the flooring.
I'd need to lift ALL the flooring in ALL of my house!
That's just not going to happen.

I've already done this for all the visible and easliy-accessible
pipework :-(

Actually, this is something I do every few years as part of the
system servicing. I usually find a couple of radiator stop valve
shafts which seep and I swap them out, even though the leak isn't
yet bad enough to emerge from under the cap.

The other place I've found a leak is the O-ring seal on a radiator
bleeding plug, but that was just after I had removed and refitted
it to add inhibitor - it didn't seal after refitting.


Yes, I know what you mean.
But it's an inherent flaw in sealed systems.

No system of pipework that snakes around a house is 100% pressure tight.
Over time ( days / weeks /months /years )the pressure *will* drop.
It's just a matter of what you can live with.

Hassle of finding-and-fixing versus hassle of re-filling.

I'm probably going to DIY an auto-filler.
It will probably be against regs.

--
Ron

On Mar 31, 10:53*pm, Ron Lowe wrote:
I'm probably going to DIY an auto-filler.
It will probably be against regs.

Oh yes, and solenoid valves do have an unfortunate habit if sticking
open on mains water. Some/many (bigger ones?) are diaphragm valves
with a very small solenoid pilot valve. The only one I used on a very
critical mains water supply stuck on at a very inconvenient moment.
Washing machine valves seem to work OK, mostly. I'd probably supply
your system through a PReducing Valve set at less than 3 bar (usual)
operating pressure of the P Relief Valve.

On 31/03/2011 23:14, Onetap wrote:
On Mar 31, 10:53 pm, Ron wrote:
I'm probably going to DIY an auto-filler.
It will probably be against regs.

Oh yes, and solenoid valves do have an unfortunate habit if sticking
open on mains water. Some/many (bigger ones?) are diaphragm valves
with a very small solenoid pilot valve. The only one I used on a very
critical mains water supply stuck on at a very inconvenient moment.
Washing machine valves seem to work OK, mostly. I'd probably supply
your system through a PReducing Valve set at less than 3 bar (usual)
operating pressure of the P Relief Valve.


It would need to be set to *considerably* less than 3 bar. Otherwise, if
it cranks it up to nearly 3 bar when cold, it will over-pressure when hot.
--
Cheers,
Roger
____________
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checked.

Ron Lowe wrote:

I've considered building an 'auto-fill' device, involving pressure and
temperature sensors, and timers. Â* It would come on at pre-defined
times, when the system is cold, and below a lower threshold pressure. It
would open the solenoid valve untill the pressure reached an upper
pressure threshold ( or a 10-second timer times out to prevent flooding
if major leak ).

Anyone tried anything similar?


Commercial systems I work on have "mini-fill" auto top up with built in
pumps.

One biomass district heating system, supplying 54 dwellings, which I visited
had simply left the mains flexi tail connected ;-(

AJH