Buying a purifier is the easy part. Then a technician turns up with a drill, a bag of fittings and ten minutes to decide where everything goes. A little planning beforehand means a neater installation, easier servicing, and no surprises with leaks or a socket on the wrong wall.
Wall-mounted vs under-sink vs countertop
| Type | Best for | Needs | Watch out for |
|---|---|---|---|
| Wall-mounted | Most Indian kitchens | Sturdy wall near the sink, inlet and drain, socket | Takes wall space; must be at a comfortable height |
| Under-sink | Modular kitchens with clear wall and counter space | Cabinet space, ventilation, socket inside, hole for a separate tap | Harder to service; leaks can go unnoticed |
| Countertop | Rented homes, small kitchens | Counter space, nearby inlet and socket | Takes counter space |
| Gravity (non-electric) | Low-TDS municipal water, unreliable power | Just counter space | Manual filling; no RO |
Wall-mounted: what to plan
- Wall strength: the unit, full storage tank included, is heavy. Tiled concrete or brick walls take screws and anchors well. Thin partition boards may not. Ask the technician to check.
- Concealed pipes and wiring: show the technician where you know pipes and cables run, so they don’t drill into them.
- Height: the dispensing tap should be high enough to fill your tallest jug or bottle comfortably, but low enough for everyone at home to reach.
- Position: close to the sink so the inlet and drain lines are short, but not directly above the sink basin where splashes reach the unit.
Under-sink: what to plan
- Cabinet space: measure the cabinet’s inside height, width and depth, and compare it with the dimensions in the manual. Remember the pipes, the sink bowl and the drain trap take space too.
- A separate dispensing tap: usually needs a hole in the sink deck or countertop. Granite or quartz may need drilling by someone with the right tools.
- Ventilation and leaks: a closed, damp cabinet isn’t ideal for electronics. A drip tray or leak detector can help.
- Service access: the technician will need to reach the filters easily. Don’t block the cabinet with stored items.
The inlet connection
The purifier needs a cold-water supply. Typically the installer fits a tee connector on the line feeding your kitchen tap, with a separate inlet valve for the purifier.
- Choose the right source. If your kitchen has both a municipal line and a borewell or tanker line, connect the purifier to the one you actually want to drink. Make sure the purifier type suits that water. Our RO vs UV vs UF guide and borewell water purifier guide can help.
- Never connect to hot water. Keep the inlet away from geyser lines.
- Ask for a sediment pre-filter on the inlet if your water is muddy, especially in the monsoon. It protects the purifier’s internal filters and is cheap to replace.
Water pressure
RO purifiers have a working pressure range, which the manual states.
- Low pressure (common with gravity-fed water from an overhead tank on a low building) is handled by the RO’s built-in booster pump.
- High pressure (from a direct pressurised line or a home pressure pump) can stress fittings and filter housings. The installer may suggest a pressure-reducing valve.
If your pressure varies a lot through the day, mention it to the technician.
The drain line
RO purifiers send reject water down a drain line. Decide where it should go before installation:
- Into the sink drain: the installer clamps the line to the waste pipe. Tidy, but every litre is lost.
- Into a bucket or container: you can reuse the water for mopping, flushing and washing. Our guide to reducing RO water wastage explains how.
Ask for the drain line to be fixed securely so it doesn’t slip out and flood the floor.
Power
Electric purifiers need a reliable supply:
- An earthed 3-pin socket within reach of the power cord, ideally with its own switch.
- No extension cords or multi-plug adaptors on a damp kitchen wall.
- The socket should be away from water splashes. If it’s below the unit, fit a cover or keep a drip loop in the cable.
- If your area has frequent voltage fluctuations, ask the brand whether they recommend a stabiliser for their model.
For under-sink models, a socket inside the cabinet is usually needed. Arrange it with an electrician before installation day.
Where not to put it
- Next to the gas stove, where heat and grease build up.
- In direct sunlight, which can heat the tank and encourage algae in translucent parts.
- Directly over the sink basin, where splashes hit the electronics.
- Behind the fridge or inside a closed shelf, where airflow is poor.
- Too high, where family members have to stretch to reach the tap or the jug won’t fit beneath.
Day-one checks
Once the technician finishes:
- Run and discard the first tankful or two, or as the manual instructs, to flush the new filters.
- Check every joint for drips: inlet tee, valve, filter housings and drain.
- Test the TDS of the tap water and purified water. Our TDS meter guide shows how. Ask the technician to set the TDS controller if your purifier has one.
- Confirm the auto shut-off works: when the tank is full, the pump should stop and the drain should stop flowing.
- Note the installation date and keep the invoice and warranty card safe for future filter changes and claims.
Bottom line
For most Indian kitchens, a wall-mounted purifier near the sink is the simplest and easiest to service. Under-sink works well in roomy modular cabinets if you plan the tap hole, socket and access. Whatever you choose, sort out the inlet point, water pressure, drain line and an earthed socket before the technician arrives, keep the unit away from heat and sunlight, and check for leaks and TDS on day one.
Frequently asked questions
Is wall-mounted or under-sink better for a water purifier?
Wall-mounted is simpler and more common in Indian kitchens: it needs only a wall near the sink and a socket, and servicing is easy. Under-sink keeps the counter and wall clear but needs cabinet space, a hole in the sink or counter for a separate tap, and a socket inside the cabinet. Choose based on your kitchen layout.
Where should the water purifier inlet be connected?
Usually to the cold-water line that feeds your kitchen tap, using a tee connector and a separate inlet valve so you can shut off the purifier without cutting off the tap. Connect it to the source you want to purify, and never to the geyser's hot-water line.
Does an RO purifier need a particular water pressure?
Yes. RO purifiers have a working pressure range, which the manual states. Most include a booster pump for low pressure from an overhead tank. If your line is fed by a pressure pump or comes at high pressure, the installer may recommend a pressure-reducing valve.
Can I install a water purifier myself?
Gravity purifiers need no installation. Electric RO and UV purifiers are usually installed by the brand's technician, often as part of the purchase, and DIY installation may affect your warranty. You can still prepare the space, socket and inlet point in advance to make the visit quicker.
