How to protect central heating systems from freezing?
Freezing of the central heating system may cause serious problems. Ice is approximately 10% larger in volume than water. In addition, it obstructs the flow of the fluid in the system. Freezing of the central heating system can lead to burst pipes and valves, which will require costly repairs. In the worst case scenario, the burst pipe may be the one under the kitchen tiles.
Modern central heating systems
The automatic equipment used in modern central heating systems allows to maintain water temperature at a safe level. However, such a solution can be ineffective, for example during a power failure or when no fuel is supplied to the furnace. There is also a problem when the user needs to leave for a longer period of time. Another important factor is the condition of insulation in the building.
On the other hand, even minor, local freezing in the system can cause problems. Although it may not necessarily damage the pipes, small pieces of ice can get into the pump and auxiliary equipment, disrupting their normal functioning. For this reason, it is very important to properly prepare your centralheating system for cold winter nights.
How to prepare a central heating system for sub-zero temperatures?
It is worth to take into account protective measures already at the design stage of the central heating system. However, such measures will not ensure complete safety against low temperatures. For this reason, if you are planning to leave for a longer period of time or if a heavy frost is forecast, you should prepare your system in advance to withstand harsh conditions.
Designing the system
Systems at particular risk of frost are those installed in holiday cottages or cabins. However, even in residential buildings there are places when the systems are vulnerable to freezing, such as those installed in attics and basements, as well as uninsulated pipes along external walls. That is why when designing your system you should avoid such places as much as possible. If you have no choice but to route the piping up into the attic, you should remember to protect the pipes with thermal insulation foam. In certain places, it is worth to consider installation of electric heating cables to prevent the system from freezing.
Topping up the system with glycol
Antifreeze has a much lower freezing point than water. Topping up the system with antifreeze prevents it from freezing. Before filling the central heating system with glycol, water must first be drained. The system should be topped up with a fluid with the right concentration of glycol.
This is one of the most common solutions, as it brings down the freezing point (it can be used in temperature as low as -25°C), and enables continuous operation of the central heating system. Glycol is also used in many other types of systems, including solar installations and various types of heating and cooling systems.
Fluids for central heating systems should be environmentally friendly and have PZH hygienic approval, to ensure that even in the event of their accidental release, they do not pose a danger to health. In addition, special additives reduce the evaporation rate of glycol, decreasing the frequency of topping up the fluid.
The disadvantages of this solution include higher load on the pump and higher price. Glycol has a higher viscosity, increasing the required pumping power. However, this is negligible in terms of both the electricity bills and the service life of this equipment. The price of glycol solutions is much higher than water, but the overall costs will be much higher in the event of potential breakdown and the need for costly repairs. Moreover, once used to fill the system, the solution can last for years.
Draining water from the system
The most common way of dealing with very low temperatures is draining water from the heating system. After doing so, the central heating system may not be used until it is filled again with water or antifreeze. However, the absence of water in the pipes effectively prevents freezing of the system.
Protect your heating system
In order to avoid problems with your central heating system it is a good idea to protect it against severe frost, especially in the case of holiday cottages or other buildings left unattended for long periods of time. In such cases, the cheapest solution is to completely drain the pipes.
The situation is different in the case of buildings that require continuous heating. Automatic furnace control systems allow to maintain a safe water temperature to avoid its freezing. However, in some cases, part of the piping may have to be routed through areas where there is a risk of local freezing. A good solution to this problem is to protect such piping sections with thermal insulation foam. Another good method is to fill the entire system with antifreeze fluid, such as FACTORY GLY.
Central heating systems should always be properly protected against sub-zero temperatures, which can cause considerable and costly damage.
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