In an RO + UV purifier, the UV lamp kills bacteria and viruses that RO or the storage tank may let through. Because it works silently, a dead UV lamp often goes unnoticed for months. Here is how to check it.
How the UV stage works
Water flows through a steel or plastic chamber around a quartz sleeve. Inside the sleeve, a UV-C lamp (commonly 11W in homes) shines on the water and damages the DNA of microbes so they cannot multiply. The lamp is driven by a small electronic choke (ballast).
Signs the UV lamp or choke has failed
- The UV indicator light on the purifier is off or blinking.
- No blue glow visible through the UV chamber end cap (on models where it is visible – never look directly at a UV lamp).
- The water has started to smell or taste stale.
- The lamp is more than a year old.
How to check safely
- Switch off and unplug the purifier. UV light harms eyes and skin – never look at a lit UV lamp.
- Check the UV indicator first, and whether the UV connector is plugged in properly.
- Check for a burnt smell or blackened ends on the lamp.
- If you have a spare lamp, swap it in – if it lights, the old lamp was dead; if not, the choke is the likely fault.
- Make sure the quartz sleeve is clean and not cracked.
Lamp or choke – which one has failed?
| Symptom | Likely fault |
|---|---|
| Lamp ends blackened, old lamp | UV lamp |
| New lamp also does not light | UV choke / ballast |
| Indicator off, choke smells burnt | Choke |
| Everything off – pump also not running | SMPS/power – see SMPS guide |
We stock the Philips UV choke EB-S 118 (₹225). For a UV lamp of your exact size, send a photo on WhatsApp and we will confirm the match.
How often should the UV lamp be replaced?
Most home UV lamps are rated for roughly 8,000–9,000 hours, and the UV output weakens before the lamp actually stops glowing. Replacing it about once a year is a safe rule – add it to your RO maintenance checklist.
Frequently asked questions
Can I use the RO if the UV lamp is not working?
RO still reduces TDS, but the extra germ protection is gone. Replace it soon, especially for borewell or tanker water.
Is UV light visible from outside?
Some purifiers show a small blue window or indicator. Never open the chamber while the lamp is on.
Does UV reduce TDS?
No. UV only disinfects; RO reduces TDS.
Need help choosing the right part? Send a photo of your RO or its model name on WhatsApp (96252 23245) and we will tell you exactly what fits. Original parts at wholesale rates, Cash on Delivery and All India delivery.
Need the right part for your RO?
Original filters, membranes and pumps at wholesale rates. Send us a photo of your RO – we will tell you exactly what fits.
