# ChatGPT — raw output, 2026-09-14 09:16 (+07), free, default model, one message, no follow-ups Interface Russian; answer in English. Ran a web search and answered over about a minute with source chips (Leroy Merlin, "Plumbing Advice", Checkatrade, YouTube, "Basic Lowdown"), an ASCII diagram of the tap, and a "Загрузить фото" (upload a photo) offer at the end. Captured from the DOM (the copy button was avoided because the operator's clipboard was in use); source-chip labels are kept as they appeared. Chat URL kept open for review. --- Yes — this is a very reasonable first plumbing DIY job. A single-lever mixer that drips from the spout while fully closed is usually suffering from a worn ceramic cartridge, and after ~10 years that is a very plausible failure. [Plumbing Advice +1] The important trick is don't buy the cartridge before you remove the old one. "35 mm" is common, but diameter alone isn't enough; the base shape, locating pins, height and spline/handle connection also need to match. [Leroy Merlin +1] ## What to buy in Portugal At a Portuguese hardware shop, ask for: > "Um cartucho cerâmico para torneira monocomando de lavatório. Quero substituir este — pode ajudar-me a encontrar um igual?" Take the old cartridge with you if possible. You may hear these terms: torneira monocomando = single-lever mixer tap · cartucho cerâmico = ceramic cartridge · torneira de lavatório = basin tap · cartucho 35 mm / 40 mm = cartridge diameter 35 mm is very common. For example, Leroy Merlin Portugal currently lists 35-mm ceramic cartridges around €5–€19, depending on brand/type. [Leroy Merlin +1] I'd buy: 1 × exact replacement ceramic cartridge · small tube of plumbing/silicone grease suitable for O-rings — optional but useful · a replacement retaining nut is not normally necessary, so don't buy one unless the original is damaged. ## Tools You probably already have most of these: adjustable wrench / chave inglesa · small Allen-key set / chaves Allen · small flat-head screwdriver · Phillips screwdriver, just in case · old towel · rag · flashlight · small container for screws · optional: adjustable water-pump pliers. Don't use ordinary pliers directly on chrome surfaces — they'll scratch it. Wrap a rag around the part if you have to grip it. ## Step-by-step **1. Prepare the basin** — Put the plug in the drain. This sounds silly, but there is a surprisingly good chance that your tiny handle screw will fall directly into the drain otherwise. Put a towel around the bottom of the basin too. **2. Shut off the water** — Under the basin you'll normally have two small isolation valves — one hot and one cold. Turn both clockwise until they stop. Then open the tap. You should get a short burst of remaining water and then nothing. If water continues flowing strongly, stop. Don't start disassembling the tap until you've actually isolated the supply. If there are no isolation valves, you'll need to shut off the appropriate main water supply instead. [Plumbing Advice] **3. Remove the lever** — Look closely at the single lever. There is usually either a little red/blue decorative cap, or a tiny hole containing an Allen screw. Pop the cap out gently with the small screwdriver if necessary. Then loosen the screw — commonly an Allen screw, often around 2–3 mm, although designs vary. [YouTube] You don't necessarily need to remove the screw completely. Once it's loose, pull the lever straight upward. If it doesn't move easily, don't immediately start attacking it with pliers. Years of limescale can make it stick. **4. Remove the decorative cover** — Under the handle you'll usually find a chrome dome/collar. Unscrew it. Depending on the tap, this may be hand-tight. If it's stuck, use a cloth and adjustable wrench very gently. Underneath you'll find the cartridge-retaining nut. **5. Remove the retaining nut** — This is the important part. [ASCII diagram: LEVER → chrome collar → RETAINING NUT ("remove this nut") → CARTRIDGE → TAP BODY] Use the adjustable wrench. Do not put huge force into it. If it feels completely seized, stop and reassess. On a 10-year-old tap, limescale/corrosion can make this the point where a DIY job turns into a damaged tap body. [Checkatrade] **6. Remove the old cartridge** — Once the retaining nut is off, pull the cartridge vertically upward. It may come out easily. Or it may be stuck. If it's stuck: wiggle it gently left/right; try pulling upward; use a cloth for grip. Don't start levering aggressively against the tap body. Once it's out, this is your shopping reference. **7. Identify the replacement** — Measure: cartridge diameter; overall height; shape of the bottom; location of the two/three locating tabs; top/handle connection. Take a photo of the old one and, ideally, take it to the hardware shop. A 35-mm cartridge that looks approximately right isn't necessarily correct. The locating pins need to land in the corresponding holes in the tap body. [Leroy Merlin +1] **8. Clean the inside of the tap** — Before putting the new cartridge in, inspect the cavity. If you see limescale, bits of old rubber, dirt, wipe it out carefully with a rag. Don't aggressively scrape the brass/plastic seating surface. **9. Install the new cartridge** — Put the new cartridge into the tap body. Pay attention to orientation. The locating tabs underneath must line up with the holes/notches in the tap body. It should sit down properly. If it won't seat, don't tighten the retaining nut to force it down. Remove it and check the orientation. A correctly positioned cartridge should essentially drop into its locating points. [Basic Lowdown] **10. Reassemble** — In reverse: cartridge in; retaining nut on; tighten the nut firmly but not brutally; chrome collar back on; lever back on; tighten the little Allen screw. Don't overtighten the retaining nut — excessive force can damage the cartridge. [Leroy Merlin] **11. Turn the water back on slowly** — This is where I'd be particularly cautious as a first-timer. Open the two isolation valves slowly. Watch underneath the basin. Check: both flexible hose connections; around the tap body; around the cartridge area; around the base of the tap. Then operate the lever. Finally, close it completely. The spout should stop dripping. ## What if it still drips? There are three possibilities. **A. You bought the wrong cartridge** — very common. The cartridge needs to match the tap's geometry, not merely its diameter. **B. The cartridge isn't seated correctly** — remove it and check that the locating tabs are correctly positioned. **C. The tap body itself is damaged** — this is where I'd stop. If you've installed a correctly matched new cartridge and it still continuously drips from the spout, don't keep tightening things harder. The tap body/seat may be damaged, or the replacement may not actually be compatible. ## When I'd call a plumber For your first plumbing job, I'd use this rule: **DIY is fine until something requires significant force.** Stop and call a plumber if: you can't fully isolate the water; the retaining nut is completely seized; the cartridge won't come out without aggressive force; the tap body starts twisting; you crack/bend a pipe or flexible hose; water starts leaking from somewhere you weren't expecting; the new cartridge doesn't solve the dripping; the tap body itself is badly corroded; you discover the tap is an unusual proprietary model and can't identify the cartridge. The biggest mistake would be thinking "I'll just give it another turn with the wrench." That's how a €10–20 cartridge replacement can become a €100+ tap/plumbing problem. ## My recommended approach Since you've never done plumbing, I'd actually do this as a two-trip job: **Trip 1:** Shut off water → disassemble → remove cartridge → photograph/measure it. **Trip 2:** Take cartridge to the Portuguese hardware shop → say "cartucho cerâmico para torneira monocomando" → get an exact match. Then installation should be relatively straightforward. If you want, a photo of the tap from above and underneath the basin would let me identify where the screw, cartridge and isolation valves are likely to be before you start. [Загрузить фото] --- First read: all six checklist steps present and in order (isolate, open the tap, lever off, collar and retaining nut, cartridge out and matched, refit and reopen slowly), plus the plug-the-basin tip. Portuguese phrasing to say at the counter. Stop-and-call list is the fullest of the nine. Asks for a photo at the end. Checks in the sheet.