# outside oil boilers freezing



## esox (20 Dec 2010)

Hey,

just a quick comment...should you have an outside oil fired boiler in my opinion its best to leave them timed on for 15 mins every 2hrs when you are not in the house. just until this deep freeze ends.

kind regards


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## Eithneangela (20 Dec 2010)

Is that because the oil freezes?  Our oil boiler is outside, so far so good, but then we do live in the sunny south east.


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## Gervan (21 Dec 2010)

I don't think the oil freezes. 
Our boiler is at the end of the garden, and the water pipe froze last night where it comes out of the ground to get into the house.


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## SparkRite (21 Dec 2010)

Eithneangela said:


> Is that because the oil freezes?  Our oil boiler is outside, so far so good, but then we do live in the sunny south east.



More to stop the *water* in the boiler from freezing and bursting the heat exchanger and/or pipes.


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## roker (21 Dec 2010)

Put anti-freeze in the system


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## SparkRite (21 Dec 2010)

roker said:


> Put anti-freeze in the system



Good suggestion Roker
+1


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## DGOBS (21 Dec 2010)

ALL outdoor boiler should be fitted with a frost protection stat


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## greentree (21 Dec 2010)

During this weather we have to leave our boiler on all the time, otherwise it just stops working until the thaw. We turn the thermostat down as low as it will go (60c) and the boiler burns less often.


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## esox (21 Dec 2010)

kerosene freezing point -30 C, 

it would possibily cost in the region of €200 to dose a central heating system of a 4 bed semi with antifreeze also will have to be replaced / refreshed every 4-5 years.


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## Eithneangela (21 Dec 2010)

My boiler is a black box, to me.  Where would I put anti-freeze?  I'm really interested because at the moment there is a foot of snow sitting on top of the boiler (and the shed, clothes line, frozen clothes, garden benches and chairs etc....).  The Boiler is a big thing in the back garden, which is covered by horrible steel stuff, or maybe that's part of the boiler.  Would it help if I put a blanket around it?


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## esox (22 Dec 2010)

its really good that you've snow on top of your boiler cause it means the boiler is not loosing any heat.

for example look for the house with the most snow on the roof, usually has the best insulation in the attic


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## Welfarite (22 Dec 2010)

esox said:


> its really good that you've snow on top of your boiler cause it means the boiler is not loosing any heat.
> 
> for example look for the house with the most snow on the roof, usually has the best insulation in the attic


 That's a cool way of checking! love it!


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## DGOBS (22 Dec 2010)

This is being viewed backwards.....cost of antifreeze etc, a frost thermostat costs about 20 euro! and everytime as it needs it will override the boiler controls to prevent it freezing


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## esox (22 Dec 2010)

yea frost stat is a must for any outside boiler usually comes pre installed in uptodate models, but what's happening is stat starts boiler working initially and runs up to required temperature then there is a residual heat in boiler casing long after boiler has stopped running meanwhile pipes going from boiler to house drop in temp and are freezing while the frost sits inside boiler casing oblivious to whats happening outside.

run boiler on time control costs nothing but your oil.


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## roker (23 Dec 2010)

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[*]Renders water non-corrosive to steel, cast iron, copper, brass and aluminium
[*]Combined antifreeze and protector
[*]Prevents limescale build-up
[*]Compatible with all metals and materials commonly used in heating systems
[*]Maintains efficiency so extending system life
[*]Non-toxic, environmentally friendly
[*]Protects heating and chilled water ter

*

*Product Uses *​*
*[FONT=Arial,Arial][FONT=Arial,Arial]Fernox Alphi-11 Protector is a combined antifreeze and inhibitor, which gives long term protection against internal corrosion and limescale in commercial heating and chilled water systems. Fernox Alphi-11 Protector is compatible with all metals and materials commonly used in central heating systems, including aluminium. 
For continued protection we recommend Protector levels are checked regularly (annually). The concentration of the product can be easily measured on site using a Fernox Protector test kit.​[/FONT][/FONT]*Physical Properties​*[FONT=Arial,Arial][FONT=Arial,Arial]Fernox Protector Alphi-11 contains mono-propylene glycol. 
Colour: Colourless 
Odour: Mild 
Form: Clear liquid 
pH (conc) 5.7 – 6.1 
pH (soln 25%): 7.0 – 7.5 
SG: 1.04 at 20​[/FONT]​[/FONT][FONT=Arial,Arial][FONT=Arial,Arial]°[/FONT][/FONT][FONT=Arial,Arial][FONT=Arial,Arial]C ​
[/FONT][/FONT]*Application and Dosage​*[FONT=Arial,Arial][FONT=Arial,Arial]The minimum recommended "in-use" concentration of the product is 25% in order to ensure adequate corrosion protection. This concentration will protect down to -11​[/FONT]​[/FONT][FONT=Arial,Arial][FONT=Arial,Arial]°[/FONT][/FONT][FONT=Arial,Arial][FONT=Arial,Arial]C. A concentration of 40% will protect down to -22[/FONT][/FONT][FONT=Arial,Arial][FONT=Arial,Arial]°[/FONT][/FONT][FONT=Arial,Arial][FONT=Arial,Arial]C. Alphi-11 Protector can be introduced via the feed and expansion tank or injected directly into the system via a suitable point (e.g. dosing pot). Introduce into the system after having drained a quantity of water at least equal to the amount of Alphi-11 to be added. Engage the circulating pump and have the system online for a few hours in order to achieve an even distribution. [/FONT][/FONT]*Concentration *​[FONT=Arial,Arial][FONT=Arial,Arial]25%​[/FONT]​[/FONT]​[FONT=Arial,Arial][FONT=Arial,Arial]30%​[/FONT]​[/FONT]​[FONT=Arial,Arial][FONT=Arial,Arial]35%​[/FONT]​[/FONT]​[FONT=Arial,Arial][FONT=Arial,Arial]40%​[/FONT]​[/FONT]​*Protection​*​​[FONT=Arial,Arial][FONT=Arial,Arial]-11°C​[/FONT]​[/FONT]​[FONT=Arial,Arial][FONT=Arial,Arial]-15°C​[/FONT]​[/FONT]​[FONT=Arial,Arial][FONT=Arial,Arial]-18°C​[/FONT]​[/FONT]​[FONT=Arial,Arial][FONT=Arial,Arial]-22°C​[/FONT]​[/FONT]​


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## john martin (23 Dec 2010)

Plenty of technical detail there on the anti-freeze but what would be the price on an avereage system?


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## DGOBS (23 Dec 2010)

Esox, fair point, but then place a 'pipe stat' on the flow or return pipe in the coldest part of the run and feed it back to the circulating pump to provide overrun (would usually fit this at the boiler to shift residual heat left in the boiler into the house)


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## roker (23 Dec 2010)

Don't know price, I did previous reseach, the price of antifreeze is got to be less than having burst pipes. Try the Fernox website

Not much point in having a frost stat on the boiler to protect the tank and pipes in the attic which are not on the hotwater system


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## DGOBS (24 Dec 2010)

Roker, mute point you just made, as you can't add antifreeze to them either!
and th thread here was 'heating pipes'

Tank and pipework in the attic should be protected with insulation, and if you
are in fear of freezing, then open you attic hatch to allow some warm air the circulate up there for a while.

An out door frost stat (as in open air) could also be added to provide a permenant feed to the circulating pump 
(moving water is much less likely to freeze)


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## roker (24 Dec 2010)

Dgobs. I am not sure what you mean by mute point, but we are talking about two separate system here. 
The primary circuit which goes from the small header tank circulates radiators and boiler can have anti freeze added. (some later houses now have a pressurised system without header tank)
Obviously this cannot be done to the hot water system for the taps, the thermostat mentioned was on the primary circuit and cannot help the pipes and tank in the loft this is a different problem best served by insulation.
Opening the attic hatch will allow warm moist in and cause condensation in the attic when thr air cools.


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## DGOBS (25 Dec 2010)

Yes of course some condensation will occur, but a much better option than frozen water pipes

The mute point, was, as far as the conversation was about central heating pipework as opposed to domestic water

To add antifreeze to domestic heating systems is not required once the system is properly controlled, as in stats for frost, pump overrun etc, as this would negate the need for antifreeze.

IN this country it is hard enough to get householders and plumber to correctly dose systems with the required chemicals such as inhibitor


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## roker (25 Dec 2010)

This is like saying run the car every few hours instead of putting antifeeze in.
Suppose ther is a power cut? Also recently the thermostat failed on my boiler and the Hight temp cut out did not work either, fortunatley I was around to hear the system boiling off and switched it off.


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## DGOBS (25 Dec 2010)

But your trying to crack a nut with a sledgehammer!

So your anti-freeze idea is to protect against those breakdowns of boiler stat failure or pump failure (where your heating is broken down) on those 'how many nights a year' that there is a potential for the system to freeze, and at what cost....200+ euro every 4/5 years??????

Against one or two stats (at a 30 euro cost) that are there to protect the system, at a very low cost of fuel that this would take (it's not like that system will kick in for long to prevent a freeze) and will only use the protection when it is required (on how many nights a year?) when the system
is not already in use

After all, the fact that all decent outside oil modules have frost stats fitted as standard, and practically every gas boiler manufacturer now has frost protection as an on board built-in feature, but hey, all us designers must be wrong eh! We have just worked in the industry for years, looking at all the data, considering failures, breakdowns, ect and attempting to design them out.

If anti-freeze was a viable consideration do you not think this would already be considered a standard practice, as with inhibiting system water, chemical flushing etc.

There is also further considerations, the chemicals you are touting, have not been tested in conjunction with any appliances to my knowledge, so the materials used, from metal, to seals, to plastics etc maybe effected in what manner? If a gasket breaks down as a result an floods a house, or an entire apartment block who is liable? 

Lets say there is a failure in the dhw cylinder coil or a non-return valve sticks open, the there is contamination into the domestic water, how would person (or baby/child) be at risk from the anti-freeze?

The method i propose here, is considered an acceptable standard that provides a reasonable means for protection against a domestic heating system freezing in our winter.............the choice is yours


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## roker (25 Dec 2010)

Back to my original question, how does the frost stat protect the heating header tank in the attic? which does not have hot water circulating. Fernox is a well proven product go to their website. It seems the designers got it wrong because of all the complaints about freezing up.


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## DGOBS (25 Dec 2010)

Don't you mean installers, as in sealed system with the correct protection devices installed...(or an insulated top up tank)

Actually, I give up, your right I am wrong, go spend your money and do as you please......afterall there is always one

Fernox launched this product for SOLAR!

Happy xmas and goodnight, from the artic pole of Ireland


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## losttheplot (27 Dec 2010)

Do the central heating timers just act as switches, when you set the heating to switch off does it just cut the power to the burner. If this is the case would the burner have any power to fire up to protect against frost. Is it a case that plumbers and electrcians just take shortcuts when setting these up.

Another problem I've encountered is the over heat thermostat cutting out due to residual heat when the burner swithces off, how is this prevented.


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## DGOBS (27 Dec 2010)

Overrun stats would have a permanent live feed from the 5amp spur that supplies power to the timeclock to allow override

Your residual overheats can be avoided but fitting a pipe stat (not set below 55deg) wired to the pump, this will shunt and residual heat left in the boiler into the house avoiding those overheats


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## losttheplot (29 Dec 2010)

Thanks, useful info. I'll look into getting one fitted as it's a bit of a nuisance. It doesn't seem to happen to any of the neighbours, I've turned the thermostat down to "2" but still seems to happen, not as much though. Could it be a fault with the safety thermostat?


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## DGOBS (29 Dec 2010)

Could be, that it's popping at too low a temp, most are 120deg hi limits


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## esox (31 Dec 2010)

hey dgobs, imo don't think the pump-overrun is shifting the residual heat left between boiler and boiler casing where the frost stat is located, happened to two of my new enviormax's the piping froze in no time.

I think the manufacturers need to design a stat which is inn direct contact with outside air temp. but this will create its one problems as stat will fire boiler all too often.

wot do you think?


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## DGOBS (31 Dec 2010)

Yes, the old outside stats were always a better idea (like with the weather compensators)

What part of the country are you located?


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## esox (1 Jan 2011)

mullingar, have never fitted a weather compensator as part of a boiler- rad system, have only seen it fitted as part of ufheating package think it was system-links , do you think its feasible for a domestic situation?


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## DGOBS (1 Jan 2011)

Yes, there is reasonably priced ones about, but even external stats would do


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## Shane007 (4 Jan 2011)

DGOBS is quite correct. All outside boilers and even boiler house models should have a frost stat installed. Newer outdoor models have them fitted by the manufacturer but they do require a permanent live to them and not taken from the timeclock live to the boiler. Many installations I have come across do not have this.
Frost stats normally kick in at +4C and turn off when the temperature surrounding the stat rises above this temperature. 
I would recommend installing an additional pipe stat, fitted to the flow pipe from the boiler and set to 30C. This will turn off the boiler when the water within the flow pipe reaches 30C. 
If your heating system is zoned by motorized valves, ensure the frost stat is wired to one of these to open same, otherwise the pump could be pumping against a closed circuit. Alternatively fit an automatic bypass valve between the positive side of the pump and the return pipe, set to 400mBar. This will create an open circuit around the boiler. Manufacturers recommend the latter.


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## AlbacoreA (5 Jan 2011)

DGOBS said:


> ....Lets say there is a failure in the dhw cylinder coil or a non-return valve sticks open, the there is contamination into the domestic water, how would person (or baby/child) be at risk from the anti-freeze?...



If this also an issue with inhibitors?


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## Shane007 (5 Jan 2011)

It could only be into domestic hot water which you wouldn't/shouldn't be drinking.


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## AlbacoreA (5 Jan 2011)

I thought it went into all the water hot and cold that isn't mains fed. 

Kids do a lot of odd things


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## Shane007 (5 Jan 2011)

Heating circuit pipes are completely separate from domestic hot and cold water. The only place the meet is at the coil that passes through the hot water cylinder, hence heating the domestic hot water supply.


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## AlbacoreA (5 Jan 2011)

Originally you said "domestic hot water" now you say "domestic hot and cold water". They also meet where main water gets into the heating loop. if theres a problem it can back fill into the domestic loop. DGOBS said that earlier, and also if the coil fails it will get in at the cylinder either.


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## Shane007 (5 Jan 2011)

Of course they meet at the filling loop, however, only whilst filling. Filling loops should be disconnected once filled, as per building regs. Automatic filling loops are no longer allowed.
I only said about hot and cold because you said "I thought it went into all the water hot and cold that isn't mains fed."


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## AlbacoreA (5 Jan 2011)

Well its either cold, or cold and hot is correct. It can't be both. 

Your taking a big assumption there that building regs have been complied with, or that the system was installed or modified after the regs came into force. Or that its working as designed with out any failures. 

How do you top it up if its disconnected? (regardless of why).


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## Shane007 (5 Jan 2011)

I am not sure what you are talking about, re: hot and cold. I made a statement about contamination of inhibitor/anti-freeze into the domestic supply from the heating circuit. The only place where they meet is at the coil in the cylinder or as you correctly pointed out at the filling loop if the loop is an automatic filling valve. This will also have a non-return valve.
With regard to how is it topped up, the system will have 2 stop valves and flexible hose. Just re-connect the flexi-hose, open the stop valves until the required pressure is achieved, close valves and disconnect flexi-hose. This system will also have a non-return valve installed to prevent back feed of heating circuit water into the mains feed, should the pressure be greater.


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## AlbacoreA (5 Jan 2011)

One system I saw was filled from the attic tank. No non-return valve. Someone left it open working on something else, and the system back filled into the tank. The tank feeds the hot and cold water taps, say to the bathroom. So its not beyond belief that someone brushing their teeth would ingest some of this water. Or just take a drink from it. The only cold water not fed from the tank is the kitchen. I'm mainly in the attics of older houses and I've never seen disconnected filling loop as you describe, even in houses only 10yrs old. 

I guess my point is real life is often not what always by the book.


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## Shane007 (5 Jan 2011)

I have never heard of filling a pressurized system from a tank in the attic, as you would never achieve the required pressure from gravity in a normal size house. It would have to be quite a few floors high. Of course, if the clown who did so tried, the pressure of the heating system would push the heating water back into that tank. It's certainly a new one to me.
Filling loops are only in pressurized systems, so you will never see one in an attic. They are normally located either close to the boiler or in the hot press, etc. Vented systems are filled by the expansion tank (the small tank in the attic), hence called the feed and expansion tank. This is only on gravity systems. The F & E tank is fed by a ball valve so it does not have a direct feed from the cold water supply and heating water could not pass back into the cold feed. 
You are certainly correct about real life and the book!


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## DGOBS (5 Jan 2011)

But it should be by the book, people wonder why we get so many boiler breakdowns, it is normally from shoddy 'not by the book' installations


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## AlbacoreA (5 Jan 2011)

But it illustrates your point about the danger of antifreeze. The end user may not know their system is flawed, until theres a problem.


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## esox (6 Jan 2011)

[QUOTEI would recommend installing an additional pipe stat, fitted to the flow pipe from the boiler and set to 30C. This will turn off the boiler when the water within the flow pipe reaches 30C..[/QUOTE]

shane007, are you possibly using this stat to break the connection of the frost stat, surely you can't install this on switched live or permanent live circuits...???


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## villa 1 (6 Jan 2011)

There is nothing uncommon with filling a sealed heating system with a 45 litre feed and expansion cistern. I've seen countless installations done this way.
This cistern tops up the cistern has a 15mm feed pipe that fills the heating up automatically when needed. This feed has a check valve incorporated to stop expansion up into the citern. 
Expansion within the heating system is accomodated within the usual expansion vessel.
This permanent feed will stop the need top up the heating via the mains supply cutting out needless service calls due to low pressure cut outs.


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## Shane007 (6 Jan 2011)

Hi Esox, yes you can. Permanent live to frost stat (independent of timed live or switched from timeclock), wired to pipe stat, then to switched live on boiler. Our electrician confirms this who does all our wiring installations.


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## Shane007 (6 Jan 2011)

villa 1 said:


> There is nothing uncommon with filling a sealed heating system with a 45 litre feed and expansion cistern. I've seen countless installations done this way.
> This cistern tops up the cistern has a 15mm feed pipe that fills the heating up automatically when needed. This feed has a check valve incorporated to stop expansion up into the citern.
> Expansion within the heating system is accomodated within the usual expansion vessel.
> This permanent feed will stop the need top up the heating via the mains supply cutting out needless service calls due to low pressure cut outs.


 
Well this is a new one to me. I have never seen it in 24 years and I hope I never do! Why would you even want to do it in this way. It won't work and if you have a pressure drop, it is highly likely that you have a leak, so therefore, fix the leak and not automatically top up to hide the fact. That is another reason why disconnecting the filling loops are an advantage over a gravity system that tops up if there is a leak. It will show up on the pressure gauge, i.e. zero pressure.
Sealed system with a cold pressure of 1 bar or a hot pressure of 2 bar will require a minimum heat height of 10m and 20m respectively to fill (0.1bar per meter of head height). So if there is a pressure drop, how can the system possibly top up from a gravity fed system??? You will not achieve the required pressure to fill the system. So what you are saying is basically nonsense. Your needless service calls due to low pressure cut outs are not so needless. If there is a pressure drop in a sealed system, it means there is a failure within the system, either a blow off from the 3bar safety valve caused possibly by a failure in the expansion vessel diaphram or a leak! Most householders would not know how to fix this and if you go along and install your so called fix, then I am afraid it is time for me to hang up the boots and let you off....
Apologies for ranting, but get real.


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## villa 1 (6 Jan 2011)

You can rant all you want 007 and I am getting real.
 I am 35 yrs in the business in this country both in a contracting and training capacity. I am a time served plumber( in one of the best apprenticeship systems in the world, fact)  so don't even try to question my experience. I've heard so much good talk about the NVQ training system in the UK!!
I am fully aware of the static/working pressures within a heating system both open and closed, yawn!! It is quite feasible for a boiler to work in a semisealed system once the system head for that particular boiler is satisfied. This is an option, depending on the heating appliance and I have indeed seen several systems working perfectly in this manner.
What would you do with a solid fuel heating appliance. Would you pressurise that as well. These particular systems are all over this country and are they all leaking?
You need to do a few more short strand training courses before you become a complete expert!!


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## Shane007 (6 Jan 2011)

Villa1, I am astonished by your attitude and your personal attack on my qualifications and where I obtained them. This is a forum for helping people and if you wish take it to a personal level, then I am not interested in your innuendos and sarcasim.
1. I still disagree with your theory of filling a pressurized system from a gravity feed. For example, a bungalow with room height of 8ft and 9" ceiling joints will give a head of under 3m. This will give a static head pressure of 0.3 bar. How are you going to pressurize a sealed system to 1 bar from 0.3 bar of pressure and why would you try when you can fill with a filling loop with mains fed pressure? Double this for a two storey house and you still only have approx 0.6 bar of pressure. 
2. With regard to solid fuel, nobody mentioned these as we are only speaking about pressurized sealed systems and of course if we were, we would not be pressurizing the system and therefore filling the system from a feed and expansion tank in the attic.
3. Nobody also stated that all systems are leaking. We are discussing filling a pressurized sealed system. I think you have lost your trail of thought and are trying to focus too much on a personal attack, which I believe is showing your wonderfully trained character.
4. If I am incorrect, I will gladly and openly admit so and I have no problem in doing so, but please show me in detail, in theory, in any which way you feel comfortable, but please do not try to slander my character. 

Forums are wonderful places for the general person to obtain information from eachother and we all can learn something. If situations take turns as this has, then I am afraid we have turned a win win situation into a lose lose situation. I apologise if your ego or anything else has been offended, so I will bow out and leave you to whatever you do best.


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## DGOBS (6 Jan 2011)

I love the way they even adopted the name 'automatic filling loops' for pressure reducing valves, it's great they are no longer allowed, it's a pity it's not enforced!


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## villa 1 (7 Jan 2011)

Shane 007 sorry for tweaking a nerve but you told me get real and in my estimation that is saying that I do not know what I am talking about. Bad Idea!!
I will have to re-iterate what I have already said in plain language, so lets go again.
You can feed a system boiler, gas fired, from a feed and expansion cistern and if you want proof I can pm you the housing estate(s) which is served by the Bord Gais network. 
Householders/building owners have to pay a plumber to recharge their pressurised heating system when boilers lock out due to low pressure brought on by minute leakages in pipes, fittings and gland packings in valves, not leaks!! This expense will go when the system including the heating appliance is fed from a feed cistern (which of course will satisfy the necessary pressure/head requirements).
I certainly agree that forums like these are great learning facilities and I get great pleasure in giving free helpfull advice to anyone who requires it. But you started the "spat" and I had to no other option that to give likewise back.
End of, and have a nice day!!


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