Domakihub Replace a Shower Mixer in 5 Steps — No Plumber Needed
A clear, tool-by-tool guide for swapping out a worn or leaking shower mixer yourself.
Reviewed by Domakihub home & decor pros · 2026-06-23 · 5 min read
A dripping or temperature-erratic shower mixer is one of the most common plumbing faults in Greek homes, holiday villas, and hotel bathrooms — especially after a long summer season of hard water use. The video above from This Old House walks through the valve swap on camera; this article breaks the same job into five clear, ordered steps with the local context you need. Whether you are maintaining a rental property on a Greek island or fixing a leaky bathroom in Athens, this guide will get you there without calling a plumber.
Why Shower Mixers Fail Faster in Greece
Greece has some of the hardest mains water in Europe. Calcium and magnesium deposits accumulate inside the cartridge and body of a mixer over time, causing the temperature control to stick, the flow handle to stiffen, or water to weep around the escutcheon even when the tap is closed. In coastal and island properties that sit empty for months, seals dry out and crack, making the first shower of the season a warm drip rather than a proper rinse.
For holiday rentals and hotels the stakes are higher: a guest who cannot adjust the temperature at 07:00 is a bad review. Replacing the mixer — rather than endlessly re-greasing or descaling — is usually the right long-term call once the cartridge has been replaced once already.
Choosing the Right Replacement Mixer
Before buying, identify the type of mixer already fitted. Bar mixers (also called exposed shower mixers) have both hot and cold inlets on a horizontal bar at the wall and are the most common type in Greek bathrooms. Concealed mixers hide the body in the wall and show only the trim plate and handles. Thermostatic mixers add a separate temperature-lock dial and are mandatory in hotel bathrooms under Greek hospitality regulations (they prevent scalding).
Match the new mixer to the existing centre-to-centre inlet distance — 150 mm is standard in Greece and across Europe — so the new unit drops onto the existing pipe stubs without rerouting copper. Buying a brass-bodied mixer rather than a zinc-alloy one pays off in hard-water areas: it resists pitting and the threads hold over repeated disassembly.
How to Replace a Shower Mixer: 5 Steps
- 1
Turn Off the Water Supply and Drain the Pipes
Locate the isolation valves on the hot and cold supply pipes directly behind or below the mixer — most Greek installations have them. Turn each valve clockwise until it stops, then open the mixer handles fully to drain residual pressure. If there are no isolation valves, shut off at the apartment or building stopcock. Lay an old towel in the tray to catch drips and protect the surface.
- 2
Remove the Old Mixer
Unscrew and lift off the handle covers (often a push-fit cap concealing a cross-head or Torx screw). Remove the handle screws, pull the handles off, and unscrew the escutcheon plates — these usually thread off counter-clockwise by hand or with a rubber-strap wrench to avoid scratching the chrome. Use an adjustable spanner to loosen the inlet nuts connecting the mixer body to the pipe stubs; protect chrome fittings with tape over the jaws. Once both inlet nuts are loose, the whole bar lifts free.
- 3
Clean the Wall Surface and Inspect the Pipes
Once the old unit is off, clean limescale and old PTFE tape from the pipe stubs with a cloth and a little white vinegar. Check that both pipe stubs are straight, undamaged, and protrude roughly the same distance from the wall — if one is pushed further in, a short brass extension nipple from any Greek hardware store (χρωματοπωλείο or υδραυλικά) will bring it flush. Also confirm the hot supply is on the left stub and the cold on the right, as standard; reversing them will confuse thermostatic mixers.
- 4
Fit and Seal the New Mixer
Wrap each pipe stub thread with 3-4 turns of PTFE tape (clockwise when facing the pipe end) to create a watertight seal without over-compression. Hand-thread the new inlet nuts onto the stubs, then tighten firmly with a spanner — snug but not forced, as over-tightening cracks brass nuts. Slide the escutcheon plates over the stubs before fitting the body if your model requires it. Press the new mixer bar onto both stubs simultaneously, align it level (use a small spirit level), and tighten both nuts evenly a quarter-turn at a time so the bar stays centred.
- 5
Restore Water and Test for Leaks
Turn the isolation valves slowly back to the open position and watch the inlet connections for 30 seconds before touching anything else. Then open the mixer handles: water should run cleanly, temperature should respond to the handle position, and there should be no drips at the wall plate or inlet unions. If a joint weeps, close the valves, dry the fitting, add one more wrap of PTFE, and re-tighten. Once the system is fully dry and leak-free, fit the handle covers and escutcheons flush to the wall — a thin bead of neutral-cure silicone behind each escutcheon keeps water from tracking into the wall cavity.
Rather have a pro handle it?
Get a vetted plumbing pro in your city — one number, booked in EN/EL/DE.
FAQ
- Do I need a licensed plumber to replace a shower mixer in Greece?
- For a like-for-like swap on an existing supply point, Greek regulations do not require a licensed plumber — a competent DIYer or a general handyman can carry out the work. However, any work that involves moving or extending pipework inside walls is classified as installation work and should be done or certified by a registered plumber (υδραυλικός με άδεια).
- How do I know if I need a new cartridge or a whole new mixer?
- If the mixer body is solid and corrosion-free but the temperature is hard to control or the flow is weak, replace just the ceramic cartridge first — it costs €10–30 and takes 20 minutes. If the body is cracked, the chrome is flaking, or the inlet threads are damaged, replace the whole unit. Mixers over 10 years old in hard-water areas are usually worth replacing outright.
- What is the standard inlet distance for shower mixers in Greece?
- The vast majority of bar mixers sold and installed in Greece use a 150 mm centre-to-centre inlet spacing, matching the European standard. Always measure your existing pipe stubs before buying a replacement — some older installations or imported fittings use 120 mm or 180 mm spacing, and choosing the wrong size means rerouting the pipes.