How to stop heating pipes freezing?

[rosie]

Sorry if this is in the wrong place, it's my first post here.

We have a small stone built property at about 350m near to St Mathieu in 87.

The property has a gas-fired central heating system, which we rarely use as we also have three log-burners. Last year we got our neighbours to put the heating on very low when it started to freeze, and we switched it off again mid February when we visited again. This used quite a lot of gas. It has occurred to us that our MAIN use of gas is to stop the heating sysyem freezing up[8-)], which seems self-defeating, or at least, a waste of gas/heating system.

Does anyone have the same problem, and if so, what do you do with gas prices being at an all-time high?

My husband suggested well-lagging all heating water pipes, covering radiators with duvets, blocking cellar air inlets,and draining hot and cold water supplies as far as possible, leaving the main stop valve turned off.

Will this be OK?

[Gluestick]

Simple answer is to add anti-freeze solution to the system; same as used in Ground Source heating, to prevent the "Slinkies" freezing.

Comme ça:

[Patf]

You can buy lengths of plastic foam tubing, slit down the side, that you just slip over the pipes. It's quite cheap. This is what we have on the pipes in our barn, (where the boiler is) which can get very cold.

Antifreeze is another good idea though.

It's a very expensive form of heating, as you say.

[PaulT]

Ours is currently a maison secondaire heated by oil. Over winter we turn the thermostat down to about 5 / 7 degrees when we are not there so that if the temp drops inside the heating comes on just to warm it slightly.

Discovered last winter that it you forget to turn the thermostat down and leave it at 25 degrees it uses so much oil that there is none left for your next visit - the cold and snowy first week of January.

Paul

[sid]

[quote user="Patf"]You can buy lengths of plastic foam tubing, slit down the side, that you just slip over the pipes. It's quite cheap. This is what we have on the pipes in our barn, (where the boiler is) which can get very cold.
Antifreeze is another good idea though.
It's a very expensive form of heating, as you say.
[/quote]

 

The insulation tubing you refer to works OK but I think it is primarily intended to keep the heat in, rather then keep the cold out; ie saving energy by reducing heatloss on the way to your radiators. When the heating is off, and especially if the piping is in a barn or other outbuilding, it only needs a slight gap in the insulation to allow that short length of pipe to freeze. Similarly if the split tubing doesn't close together after fitting, usually at the back where you can't see it.

Antifreeze or drain the heating completely!

 

[Gluestick]

Insulating pipes, as said already merely preserves retained heat energy. Over time, the pipes will drop to ambient room air temperature.

And anyway, what about the rads and the boiler heat exchanger?

Additionally, it is not just the heating pipes which are a problem: also the feed pipes from the rising main and the distribution pipes for domestic hot water will freeze, once the internal temperature drops below freezing point and remains so.

Thus water main should be left off: and all feed pipes installed or modified to enable proper drain-down.

Or heating of some form left on to ensure the ambient temperature within all of the house (Which areas have pipework carrying water), remains just above freezing point for the duration of the Winter: and that's November until early March, where we are!

[:-))]

[NickP]

 Gluestick, I take on board your anti freeze suggestion, but can you please explain to a plumbing Know nothing, can or how I get the anti freeze into a mains fed French oil fired central heating system. Also is there any value in some kind of electric heating for the condensation discharge pipe. Cheers [B]  

[Gluestick]

Simply, you use something like this: See here:

Course, if one wants to be flash, one can use one of these! [:D]

See here:

If was me (Or Chancer, of course![:)]), we'd knock one up from a gash garden sprayer and a nifty bit of adapter in place of a rad bleed screw.

You must de-pressurise the system to add the treatment fluid: and re-pressurise it afterwards.

Ideal solution for a sealed system, is to insert a complete anti-corrosion/anti-freeze liquid.

Any system must be operated for a couple of days after adding the liquid, to allow it to penetrate and mix right the way through.

Since the vapour condensing pipe is not under pressure and is open to atmosphere, it would only be residual water drops which might freeze, with no chance of bursting.

[Quillan]

If your heating system is what is called a 'closed' system and pressurised then you should have an inhibitor plus antifreeze in it. If you have to drain the system at any time then you should refill using such a chemical. A good old favorite is Fernox Alphi11 which can be bought in the UK, I don't know about France. Typically it costs around £160 for 25 litres which when diluted with 60% water will give protection down to -22. If you only drop to say -15 then you can dilute it with 75% water. You should flush your system before adding with something like Fernox Restorer IC-20. This stuff has been around for about 40 years in one form or another and can be used in 'open' systems also where you have a 'header tank'. It sounds like a lot of money I admit but look at it this way, unless you have a major leak and loose all the water it will last a lifetime, it means you can turn the system off and walk away, there is no corrosion in the radiators and boiler matrix which makes the system work the same the older it gets as it does not get clogged but more than anything it gives you piece of mind.

One tip, if you use this stuff and drain the system before hand put stopcocks either side of the boiler if it does not already have them. That way you can 'isolate' the boiler if there is a fault and you wont have to drain the whole system to fix it. If the circulation pump (which should last longer if you use this stuff) is separate put stopcocks either side as well just in case.

When you drain the system use a bucket who's capacity you know so that when the system is empty you know how much water is in the system to calculate the mixture you require. Don't forget to open the vent valve at the highest, furthest radiator when draining and more important don't forget to do it up again before you fill. The system should be run on full power for about 4 hours afterwards to make sure the chemical is properly mixed round the system (you put the chemical in first then the water). If your not sure then get a registered plumber to do it for you.

Finally the modern version is 'environmentally friendly', not toxic and does not harm you if you come in to direct contact.

[NickP]

Thanks Gluestick an Q for your rapid and informative reply. I shall call on the services of a local plumber to install the necessary products, it's just good to know that it can be done and what is needed before I ask for  the Devi. [B]

[PaulT]

Just think though that if you have a boiler that also houses the hot water tank that will not be protected nor the pipes serving the various basins etc. So whilst you might put anit-freeze in to the heating system think about the hot and cold water services.

[Quillan]

[quote user="PaulT"]Just think though that if you have a boiler that also houses the hot water tank that will not be protected nor the pipes serving the various basins etc. So whilst you might put anit-freeze in to the heating system think about the hot and cold water services.[/quote]

In France and like most modern UK systems now the heating side is 'closed' and preasurised. The water heating side runs off the mains with no cold water tank like we used to have. With the direct mains units you simply turn of the mains water and there will be a drain point somewhere near the lowest point of the system. Open all the taps and the drain point and simply empty the pipes. If you have a very old system with a cold water tank you can do the same thing, it just takes longer to empty. The water is normally heated by a coil if you have a hot water tank which would contain the inhibitor/antifreeze so there is no problem there.

[BIG MAC]

I would advise only opening vents when you are satisfied that water level has dropped below the level of the vent.......unless you want tthe contents of the header tank on your floor