How to install a bathroom sink mixer: step-by-step tutorial

Installing a bathroom sink mixer yourself is no rocket science — it's within reach of any amateur DIY-er, takes 30-45 minutes the first time, and saves 50-100 TND in plumber fees. Here's the complete step-by-step tutorial, with the exact tools you need and the 5 mistakes that waste half a day.

Tools and materials

Tools

• Plumber's wrench (adjustable or pipe wrench) — ~25-40 TND
• 16-18 mm flat wrench
• Phillips screwdriver
• Flashlight or headlamp
• Bucket or rag
• Cutter or scissors

Materials

• New mixer (see our price guide)
• Flexible hoses — usually included; otherwise 8-15 TND/pair
• O-ring or sealing washer — usually included
• PTFE/Teflon tape — 3-5 TND. Essential.

Verify you have everything before starting.

Step 1 — Shut off water and prep

1. Locate the two shut-off valves under your sink (cold/blue, hot/red). Turn both fully clockwise.
2. No shut-offs? Cut water at the main meter.
3. Open the old mixer to release residual pressure.
4. Place a bucket under the sink for residual water during disassembly.

Tip: photograph current connections before dismantling.

Step 2 — Remove old mixer

1. Unscrew flexible hoses from both sides with the flat wrench.
2. Find the central nut under the sink. Loosen with plumber's wrench.
3. Limescale-stuck nut? Spray white vinegar, wait 5 min, retry.
4. Pull mixer up through the sink.
5. Clean the area thoroughly.

Step 3 — Prep the new mixer

1. Unbox. Verify all parts present.
2. Screw flexible hoses into mixer body. Hand-tight + ¼ turn with wrench, no more.
3. Wrap 4-5 turns of Teflon tape (clockwise) on the flexible hose threads going to the wall side.
4. Verify O-ring is on the mixer base.

Step 4 — Position and fasten

1. Pass flexibles through the sink hole.
2. Place mixer in hole, centered.
3. Underneath: place metal washer, then mounting nut. Hand-tight, then ¼ to ½ turn with wrench. No more.
4. Verify the mixer is stable above.

Common mistake: over-tightening cracks the sink ceramic.

Step 5 — Connect to shut-offs

1. Screw each flexible end onto its shut-off valve. Hot left, cold right (verify with your photo).
2. Hand-tight, then ¼-½ turn with wrench. Teflon does the sealing.
3. Visual check: no twisted or pinched hoses.

Step 6 — Test

1. Open shut-offs slowly (¼ turn first).
2. Inspect under sink with flashlight. Wait 30 seconds — some leaks take time.
3. Test at the mixer: cold, hot, mixed.
4. Connection leak? Close water, add more Teflon.
5. Base leak? Check O-ring position, retighten.
6. Clean up. Keep packaging + receipt for warranty.

5 common mistakes

1. Forgetting to shut off water — #1 cause of flooding.
2. No Teflon — micro-leaks appear in weeks.
3. Over-tightening — cracks the ceramic. Rule: firm + ¼ turn, no more.
4. Reversing hot/cold — verify before closing up.
5. Not flushing the aerator — Teflon residue clogs it. Unscrew, rinse, re-fit.

FAQ — Mixer installation

How long does it take? 30-45 min first time. 15-20 once experienced.

Do I need a plumber? No if you can use a wrench. Yes for old installations without shut-offs.

Stuck nut? Vinegar, wait 5-10 min, retry.

Can I reuse old hoses? No. They age in 5-7 years.

Leak after install? Base: check O-ring. Joints: more Teflon.

Summary

Installing a mixer:

1. Shut off water
2. Remove old
3. Prep new (Teflon!)
4. Position + fasten
5. Connect
6. Test

Total: 45 min first time. 50-100 TND saved. Plus the satisfaction.

See our mixers in stock — delivery throughout Tunisia, cash on delivery.