If you are closing your holiday home for winter and not returning until the following season.
Drain down of the freshwater system is essential when closing your holiday home over the winter months.
Fresh water freezes at 0 degrees Celsius and can expand by 9% which can cause excessive force and can destroy
- Pipework
- Boiler Components
- Taps and shower valves. (It is recommended that shower valve/s are removed and stored safely once the water has been turned off and drain cocks opened).
If you leave fresh water in the system of your holiday home during the colder months you will run the risk of any or all the above damage.
Frost and Ice cause damage by two methods.
- Water freezing within appliances, pipes, taps or TMV valves
- Water pressure increasing within the entire system caused by water freezing in pipes external to your holiday home.
It is vital that before closing your holiday home for winter that a proper drain down procedure is carried out.
Because of the destructive power of water, and the damage that can result from a cold weather failure Atlas would recommend that to avoid any potential problems, and to ensure a proper drain down that the drain down process should be carried out by a recognised/specialist tradesman with the correct equipment to capable of blowing water out of the system, and a refractometer to check the anti-freeze levels
Your park will often be able to recommend someone who is experienced at this procedure.
*The above does not apply to the central heating system which is a self-contained pressurised system which should be regularly maintained by a qualified gas safe engineer.
However, the antifreeze level should be checked prior to any winter period using a refractometer to determine if the level of antifreeze is too low. A system with insufficient antifreeze/corrosion inhibitor is diluted and protection is very much reduced.
Living in your holiday home over winter.
You may feel that your home is not at risk of frost related damage when you are using the home full time during the winter months but BEWARE. During the last couple of winters due to extreme drops in temperature Atlas had many examples of boilers and mixer taps etc being damaged overnight even though the owners/customers were staying in the home and had the central heating on. This phenomenon has been known to Morco, our boiler supplier for some years but the lack of a really cold winter meant that the theory had never been put to the test. What happens is that the home, including the boiler cupboard, remains warm due to the central heating being on. Obviously, no damage due to ice formation can occur in these circumstances. However, nearly all holiday homes have the hot and cold-water pipes hung underneath the home. These pipes are lagged in line with the Water Regulations 1999 and with National Caravan Council standards, but they will only protect the water within the pipes from freezing for a period in cold conditions. While you are sleeping in a warm bed** with the combi boiler circulating the antifreeze/water/corrosion inhibitor mix in the sealed heating circuit around the radiators, the mains water inside the hot and cold pipes under the home is turning to ice. This has the effect of compressing the water that is still unfrozen elsewhere in the system. This water may be in the pipes under the van, inside the boiler, in the pipes inside the home and in the shower mixers or mixer taps. As the ice continues to form, the pressure increases. Combi boilers are usually specified to cope with mains water pressures up to 10 bar, TMV2 shower mixers will generally be in trouble at pressures above 6 bar. The hot and cold-water pipes under the typical home have a capacity of 3.6 litres. As ice forms, that volume increases to 3.925 litres and, as water is pretty much incompressible, this extra 0.325 litres needs to go somewhere. Depending on where the water turns to ice in the pipe, it may push apart a pipe fitting under the van, or it may blow O ring seals out of the boiler hot/cold water components or cause irreparable internal damage to shower mixer valves.
**There are 2 reasons why the problem is largely caused overnight:
- Temperatures are lower at night
- The hot and cold-water outlets are not in use as the owner and their family are asleep. Continually using hot and cold water during the day draws through the water that is about to freeze under the home and replaces it with water from pipes that are buried underground that may be 5-10°C warmer
Intermittent use of your holiday home during winter.
This is the most difficult to advise on as the only risk-free solution is to have an engineer drain down your home every time you leave the park. We appreciate this is an expensive approach, but it is the only one that is failsafe. You can choose to turn off the cold-water supply and carry out your own drain down without blowing the cold water through the pipes. You can also remove the shower mixer valves, leave electric power and a gas supply to the boiler so that the boiler frost protection works. All these will help to avoid damage, but they will not guarantee that no damage will occur.
For further in-depth information and helpful tips on the drain down procedure and levels of antifreeze we recommend that consult the Atlas handbook, or go to https://morcoproducts.co.uk/articles/winterisation-of-holiday-homes-with-central-heating-systems/
Take a look at our Owner's Handbook here 👉 Owner's Handbook
NB* Due to the arbitrary nature of damage caused by frost/extreme temperatures this damage cannot be covered by any warranty policy and claims for damage caused by frost and subsequent water damage should be referred to your insurance company.
