Protection of installations against freezing - what are antifreeze valves?
A failure of the heating system is a scenario that no one wants to experience - whether at the beginning of the season, when starting the heat pump for the first time after a break, or in the middle of winter, when the temperature drops exceptionally low. A small thing may decide whether a failure occurs - a momentary power outage, downtime of the circulation pump or simply an exceptionally long frost, sufficient for the water to freeze in the installation. This is prevented by an antifreeze valve. In this article we explain what what is this device, how does it work and in what situations is it actually useful.
Serious and expensive consequences of inattention
Frozen water in the installation does not only mean a lack of heat in the house - it is a real physical risk equipment damage. When water turns into ice, it increases its volume by almost 9%. enough to burst the pipe or damage the heat exchanger from the inside. In practice it means it's not a minor fault, but a major repair - the cost of such a failure is usually several, and sometimes even several thousand zlotys, in addition to the installation downtime in the worst possible case moment of the season.
Freezing most often occurs when:
- due to lack of electricity, the circulation pump does not force the flow, which results in faster cooling of the medium;
- the controller or anti-freeze function in the pump software will work incorrectly or not at all;
- the installation is started after a longer downtime, late in the heating season - especially after periods of frost.
Active installation protection - controller and circulation pump - only works when when the device is actually working and has Power supply. Therefore, it is a good complement to these protections is a purely mechanical solution that protects the installation regardless of whether in particular moment it is launched.
What is an antifreeze valve (and its other names)
It is a small thermostatic valve mounted on the heating system pipeline, and its task is to: protection of the heat pump against frost by dumping (bleeding) the medium before the water freezes critical point. In the industry it also functions as: anti-freeze valve, valve antifreeze, antifreeze valve and dump/drain valve for the pump heat. This protection complements the controller's automation, not replaces it - it works regardless of electronics and power supply.
How the antifreeze valve works
The operation is fully mechanical, thermostatic - without electricity and without a signal from the controller. Element thermostatic reacts to the temperature of the medium flowing through the valve:
- when the medium temperature drops to approximately 3°C, the valve opens the bleeder and some of the water begins to flow outside;
- the outflow draws warmer water from the installation in its place, which increases the temperature at a critical point;
- after the temperature rises to approximately 4°C, the valve closes.
The exact opening and closing temperature thresholds and maximum operating pressure vary models - the above values are typical market thresholds, not a rigid standard. It's worth it verify in the catalog card of a specific valve.
How and where to install the valve - the most common mistakes
- Number of valves. Usually two - one on the supply, the other on the return from the outdoor unit, as close to the heat pump as possible.
- Location. The coldest, most exposed point of installation.
- Position. Vertical, discharge directed downwards so that the medium flows freely.
- No insulation. The valve must not be insulated or installed near heat sources - it must "feel" the actual ambient temperature.
- Spacing. Min. 15 cm from the ground and min. 15 cm horizontally between two valves - too small a distance may cause the lower valve to ice up due to water flowing from the upper one.
The most common mistakes are: insulating the valve together with the pipe, installing it in a place protected from cold and omitting the second valve in one of the circuits - each of them can defeat the purpose of protection. Equipment dedicated to proper installation in central heating installations. you will find in our online catalog, in the category installation accessories.
glycol, Power supply emergency (UPS) or valve - what to choose
The valve is not the only way to protect the installation. This type of frost protection can be constructed in several ways - and none of them is the only right solution. Each of them finds its application in specific circumstances. The key is to understand how each of these methods actually works.
- Glycol it lowers the freezing point of the medium in the entire installation, but changes its hydraulic parameters, slightly reduces the efficiency of heat exchange compared to pure water and requires regular monitoring of the concentration. This is a system solution, planned at the design stage - not a point protection that can be retrofitted at any time.
- Power supply emergency (UPS) maintains the operation of the controller and circulation pump during a short power outage. However, it will not help if the controller itself fails, and its effectiveness depends on the battery capacity.
- Antifreeze valve works fully mechanically and thermostatically, without electricity and without the use of electronics - it protects the installation regardless of whether the controller, circulation pump or itself fails Power supply. This is the last line of defense if other protections fail.
The most failure-resistant type is an installation that combines these methods: an efficient controller supported by an emergency power supply, correctly selected circulation pump and mechanical valve as protection in the event of power failure.
Related installation items
- Circulation pump — maintains a continuous flow of medium, reducing the risk of local cooling. A proven and recommended solution from the IBO catalog is our energy-saving circulation pump BETA 2 25-60/180.
- Expansion vessel — compensates for changes in the volume of the medium; we have in our assortment wide selection tanks dedicated to heating installations; Before the heating season begins, it is worth checking the correct operation of this element of the installation.
- Magnetic separator — protects the antifreeze valve itself against clogging with sediments and impurities from the installation (including magnetite resulting from corrosion), which could block its narrow discharge channel at a critical moment. You will find a proven solution in the category separators and iron removers on our website.
IBO antifreeze valves are available in several connection sizes: IW 1 1/4", IW 1 1/2" and IW 1". If you need help selecting the appropriate valve or other IBO device for your installation, please contact us contact with our technical support department.
FAQ - frequently asked questions
Is an antifreeze valve sufficient as the only protection against frost?
This is an effective mechanical emergency protection, but it works best as the final line of protection for your installation - we recommend using it as a complement to efficient controller automation and a correctly selected circulation pump.
At what temperature does the antifreeze valve open?
Typically, when the medium temperature drops to approximately 3°C, it closes after rising to approximately 4-5°C - the exact thresholds vary between models.
Does the antifreeze valve work without electricity?
Yes - it works fully mechanically and thermostatically, without electricity, so it protects the installation even during a power outage.
How many valves are needed in a heat pump installation?
Usually two - on the supply and on the return from the outdoor unit, as close to the heat pump as possible, at the coldest point in the installation.
Can the valve be insulated together with the pipe?
NO. The valve must be in contact with the actual ambient temperature to operate at the right moment.
Glycol or antifreeze valve - which protects the installation better?
These are solutions of different nature: glycol lowers the freezing point of the medium, and the valve provides point emergency protection. Both of these applications complement each other well.
Where to buy an antifreeze valve for a heat pump?
IW antifreeze valves are available in the Dambat offer from our trading partners and installation wholesalers, the current list of which can be found in the tab partners on our website.
