Yes, we generally recommend that water go through a sediment pre-filter before entering the UV light chamber. This makes sure that your water is clear enough for effective UV disinfection. If your water is cloudy, UV light may not be able to contact and destroy dangerous microbes in the water.
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If you have “hard water” (water that is high in magnesium and calcium), you’ll most likely want to install a water softener in front of the UV water treatment system. If left untreated, hard water can cause scale build up on the UV lamp, thus decreasing the UV process effectiveness.
After pretreatment has been installed, the incoming water to the UV system meet the following parameters:
If your water does not meet the above parameters before entering the UV chamber, then pre-treatment equipment may be necessary. Again, pretreatment is important because high levels of sediment, iron and water hardness may degrade the performance of your UV system and not allow it to properly treat the water.
First and foremost, if you have purchased a UV water filter with the intention of filtering or sterilizing water in your home (understood as the entire household), lamps in the range of 25W, 30W, or 55W are used for this purpose. These UV water filters are installed at the water inlet to the house, as close to the water source as possible, even within the building. Smaller UV lamps such as 16W, 11W, etc., will not suffice for sterilizing the entirety of water in a household.
UV lamps of 25W can be used in apartments or small cottages, conditionally - remembering that they must be properties with low water flows. It is also important to consider the fittings, which are typically 1/2" in size, often too small to sterilize water in a household where more than 1-2 people live.
✅ In practice, the UV water filter for home use is most commonly either a 30W 8 GPM or a 55W 12 GPM lamp. These are lamps with a 3/4" fitting and sufficient capacity to purify water - even in households with multiple occupants, as well as in areas where biological contamination of water has been detected.
We will analyze this issue point by point, documenting the most important or noteworthy moments with photographs.
The UV lamp should be connected as close to the water source as possible, but since it is a product for indoor use, it can be installed in various locations within the building. This could be the boiler room; the sterilizer does not have specific requirements, although it is recommended that the temperature is above freezing.
☑️ However, in the case of installing UV lamps in unoccupied and unheated houses during winter, it will be necessary to drain the water from the UV lamp, as freezing could cause damage.
The water sterilizer should be installed, as mentioned above, as close to the water source as possible, but within the building and after any pre-filters. These pre-filters should be selected appropriately to provide mechanical protection for the UV lamp. Unless we are dealing with a lamp that sterilizes, for example, only one faucet - in that case, a flexible approach should be taken.
✅ If hard water is an issue in our region, installing water softeners should be considered. Flow-through water softeners (galvanic cells with turbulator) with 3/4" or 1" fittings can be found in the Nordic Tec catalog.
The chosen location for installing the UV water sterilizer must have easy accessibility because approximately once a year, the bulb will need to be replaced.
The chosen location for the water sterilizer must also have access to the electrical network - the sterilizer is a classic electrical product operating at 230V, thus requiring access to an electrical socket.
After opening the box containing the UV water sterilizer, you should ensure that all components are included in the kit. This should definitely include the stainless steel sterilizer tube, two protective tubes made of thick cardboard (which should contain the UV-C bulb and the quartz sleeve), a power supply with a black electrical plug, an additional cable for the UV bulb (usually blue, occasionally another color), wall mounting brackets, and O-rings (silicone seals - at least 2 pieces).
Handle the quartz sleeve and UV bulb with extreme caution.
✅ It is recommended to wear gloves to avoid leaving fingerprints on the glass. Clean the UV bulb and quartz sleeve with a lint-free cloth using clear alcohol. Fingerprints left behind can weaken the effectiveness of UV rays - and in the case of the bulb, may even lead to its rapid burning out. (A similar phenomenon occurs with car bulbs).
Once the UV bulb and quartz sleeve are clean, proceed with the assembly.
We start by unscrewing the nuts, which are usually supplied on the threads of the UV sterilizer. We unscrew both nuts - the open-ended and the closed-ended one.
Next, we need to fit the O-rings, silicone seals, onto the quartz sleeve of our UV water purufier. We start by fitting the seal onto the open-ended cap of the glass tube - approximately 12mm from its edge, as shown in the image below.
This action requires great caution to avoid damaging the glass quartz sleeve. It should be inserted in such a way that its end protrudes on the other side of the UV sterilizer. This is illustrated in the following photographs.
Once we complete the task and the quartz sleeve is concealed inside the reaction chamber - our UV sterilizer - we will see a view similar to the one in the above picture. The quartz sleeve will not be fully concealed but will rest on the silicone seal. It is crucial that the seal is positioned at the correct distance from the edge of the glass tube. This ensures that the next step of UV lamp installation proceeds smoothly.
Fit an O-ring (seal) onto the closed end of the glass tube protruding from the opposite end of the stainless steel tube.
If the protruding part of the glass tube is too short to fit the seal, it means that the seal on the open end of the tube is set too low (i.e., at too great a distance from the tube's edge). In this case, you need to go back to the point of fitting the first seal. Remember that it should be about 1.2cm from the edge of the tube (i.e., from the hole prepared for the UV bulb).
After correctly fitting the seal on the closed end of the quartz tube, you will see a view like the one in the photograph below.
We perform the action shown in the image below - that is, we need to screw the closed nut onto the stainless steel sterilizer. The closed nut should be placed where the closed end of the glass tube is located. Many people rely on silicone O-rings as seals and do not pay attention to sealing the threads when tightening the nut. However, we recommend tightening the nut according to the accepted practice in plumbing for sealing threaded connections - using adhesive or Teflon tape.
✅ Important - we tighten the nut slowly and carefully to avoid damaging the glass tube.
We remind you that tightening the UV water filter nuts must be done with caution to protect the quartz tube.
We perform the same action on the other side of the sterilizer. That is - we screw the open nut from the side where the open end of the glass tube protrudes - into which we will later insert the UV lamp bulb.
✅ We remind you to carefully seal the thread and to tighten it gently to avoid damaging the O-ring or the tube.
If you want to learn more, please visit our website UV Water Sterilizer Installation Mistakes to Avoid.
Please remember that the UV lamp bulb should be thoroughly cleaned with a lint-free cloth and clear alcohol, and should not have fingerprints on the glass (as this can lead to rapid burning of the bulb - even shortly after it has been burned out). For this reason, it is recommended to use gloves - as shown in the attached photos in the instruction manual.
First, you should connect the blue cable to the bulb socket (there is a suitable plug there). Make sure it is securely connected to ensure a closed circuit. Then, insert the bulb into the socket from one side. Connect the 2 pins on the other side to the remaining end of the blue cable. In some kits, the cable may be a different color than blue - this has no technical significance, as the connection principle is the same. The bulb must be connected from both sides, otherwise it will not emit UV rays, and thus will not work.
At this point, we dispel doubts - many people ask whether the blue cable can be so close to the UV bulb, whether it will melt or be damaged by the temperature emitted by the UV rays. We assure you that this is a proven solution, used by our company since . It is safe and does not pose a risk of damaging the cable, which is resistant to temperatures.
After correctly connecting the bulb from both sides, it will look like the one in the photograph below:
With utmost caution, we insert the connected bulb into our UV lamp system - from the open end of the quartz tube. The bulb is inserted into the UV filter - ensuring that the cable with the power supply remains outside.
Finally, we carefully pull down the cover of the UV lamp socket - which is intended to protect the bulb's power supply from dust and moisture for a long time. If the threads have been properly (i.e., tightly) connected - we have a prepared UV lamp system - which will need to be connected to the water supply network.
Below is the UV water filter with the electrical part cover pulled down.
We remind you that the location of the UV water lamp installation must also be accessible in the future - i.e., we must have easy and unobstructed access to it in case of, for example, needing to replace the bulb in our water sterilizer.
✅ The UV lamp can be mounted vertically or horizontally.
We remind you that we must ensure that the lamp is mounted on the wall stably and securely. If we are mounting it on flexible hoses instead of solid rigid pipes - we cannot rely solely on the brackets provided in the kit - but we must purchase additional clamps from a plumbing store.
Before starting the system, make sure that all hydraulic connections are properly connected. The direction of water flow through the UV-C lamp is arbitrary.
First, turn off the water supply with the lamp still not connected to the network and check the tightness of our connection, both from the water connections side and the nuts of our UV sterilizer.
If everything is fine, leave the water turned off for a minute or two to allow any potential dust residues inside the lamp to be flushed out.
When we are sure, we turn on the UV lamp to the network, i.e., start water sterilization.
Mounting a bypass with this type of device is recommended but not necessary. However, it will allow for potential servicing of the UV lamp without draining water from the entire system. Sooner or later, there will surely be a need for service operations such as bulb replacement or cleaning of the quartz tube.
Below is a schematic of connecting the UV lamp to the water, with a visible bypass.
The schematic also shows protective filters for the lamp. Additionally, you can optionally add an electrolytic water softener if you have exceptionally hard water. It will protect the stainless steel tube and prevent scale buildup on the quartz tube, which can hinder water sterilization (it requires clarity).
Replacing the bulb is an inevitable task in the Nordic Tec UV lamp system. Water sterilization is based on a mercury bulb from Philips, but even the best brand cannot guarantee that the bulb will sterilize water for years. Typically, lamps operating continuously 24/7 (turned off only during household members' longer absences of 1-2 days) require bulb replacement after about a year.
The bulb replacement process is essentially the same as its installation. Therefore, we refer you to the previous points of the instruction.
A common question concerns the operation of the UV lamp, i.e., how the lamp operates, when it turns on, whether it operates only when water flows, etc.
✅ Definitely, the UV lamp operates continuously, i.e., in a 24/7 system - if effective water treatment with UV-C rays is desired. The Philips bulb is designed for this purpose and it is not a problem. More harmful to the bulb than continuous operation is its constant switching on and off.
???? Do not turn off the UV lamp for short periods of a few hours - do not turn off the sterilizer at night or when leaving for work, etc. To turn off the UV lamp and stop water sterilization, we should not be at home for more than 1 or 2 days (e.g., for a weekend trip).
???? Do not synchronize the lamp switch with the pump - this can damage the bulb in just a few days.
We must accept the fact that a turned-off lamp does not provide a barrier for E. coli and other water contaminants, which can then enter our water system.
We must also accept that water sterilization requires electricity consumption - and this should be taken into account at the purchasing stage. The power consumption of the UV lamp is not huge, and there is no real saving to be made on it.
You may notice the phenomenon of water heating by the UV lamp if the water remains in the sterilizer for some time. This is an incidental phenomenon and is not dangerous. Only a small volume of water (which stood in the steel tube) will be heated. Simply turn on the tap for a moment to start the flow of cold water.
Heating water by the UV lamp cannot damage the sterilizer, the bulb, etc. Ultraviolet radiation is also unable to cause water to boil, so this should be seen as an insignificant side effect. We most commonly encounter this in the morning when the water in the sterilizer has been standing overnight.
If you are looking for more details, kindly visit The Role of UV Sterilizers in Multi-Stage Water Filtration Systems.