Domakihub How to Replace a Monobloc Kitchen Tap: Step-by-Step
A confident DIY guide to swapping out a single-hole mixer tap without calling a plumber.
Reviewed by Domakihub home & decor pros · 2026-06-23 · 5 min read
A dripping or dated monobloc mixer tap is one of the most satisfying kitchen fixes you can do yourself in an afternoon — no gas, no mains electrics, and no structural work involved. The video above walks through the full replacement on a real kitchen, while this guide gives you the ordered steps, the tools you will need, and the answers to the questions Greek homeowners, landlords, and hotel managers ask most. Whether you are maintaining a family home in Athens, a holiday villa on Crete, or a boutique rental apartment, this job pays for itself the first month through a lower water bill.
What Is a Monobloc Tap and Why Replace It?
A monobloc (or monoblock) kitchen mixer tap is a single-body unit that fits through one hole in the worktop or sink deck and controls both hot and cold water through one spout. The vast majority of modern Greek kitchens use this format because it is compact, easy to clean, and compatible with standard 35 mm ceramic cartridges.
Common reasons to replace one include a cartridge that has worn past the point of adjustment, persistent dripping, a broken lever, lime-scale damage to the spout, or simply a cosmetic upgrade when renovating. In most cases the replacement tap costs €40–120 and the job takes under two hours with basic tools.
Is This a Job for a DIYer or a Licensed Plumber?
Replacing a kitchen tap is cold-water plumbing — it involves isolating the supply under the sink and making push-fit or compression connections to flexible braided hoses. This is firmly within the DIY skill range for most homeowners and does not require a licensed technician in Greece, unlike gas appliances or mains electrical panels which must be touched only by certified professionals.
That said, if your isolation valves under the sink are old, heavily corroded, or simply absent — meaning you would have to shut off the rising main to the whole property — it is worth having a plumber replace those valves at the same time. In apartment buildings across Greece the main stopcock is often in a shared riser cupboard, so identify its location before you start.
How to Replace Your Monobloc Kitchen Tap
- 1
Gather tools and buy the right replacement tap
You will need an adjustable basin wrench (also sold as a tap spanner — essential for reaching the locking nut under the sink), an adjustable shifting spanner or 22 mm open-end spanner, PTFE thread-seal tape, a small bucket and old towels, and a torch. When choosing your new tap, check the hole diameter in your sink (standard is 35 mm), the distance between the underside of the worktop and the supply pipes (this determines how much clearance you have for the locking nut), and whether your water pressure is high (mains-fed) or low (gravity-fed tank), as some taps specify minimum bar ratings. Buy a tap that includes flexible braided hoses — most modern taps do.
- 2
Isolate the hot and cold water supply
Under your kitchen sink you will find two flexible hoses running to small inline isolation valves — one for hot, one for cold. Turn each valve a quarter-turn with a flat-head screwdriver so the slot is perpendicular to the pipe. Then open the tap fully to release pressure and drain any water left in the lines. If you have no isolation valves, close the rising-main stopcock for the property and open a lower tap to drain down. Confirm the water is off by trying the tap again.
- 3
Disconnect the old tap
Place your bucket under the connections. Unscrew the flexible hoses from the tail-pieces of the old tap — these are hand-tight or require a spanner, and a small amount of residual water will spill. Now go under the sink with your basin wrench. Reach up behind the sink deck and turn the large plastic or metal locking nut counter-clockwise. On older taps this nut can be very tight; apply penetrating oil and wait ten minutes if needed. Once the nut is off, lift the old tap straight up out of the hole from above. Remove any old sealant or rubber gasket material from around the hole and wipe the surface clean.
- 4
Fit and secure the new tap
Thread the flexible braided hoses down through the sink hole first, then lower the tap body into place. Most taps come with a rubber base gasket; if yours does not, bed the tap on a thin bead of clear silicone sealant to prevent water ingress around the hole. Go back under the sink and hand-thread the new locking nut upward onto the tap tail, then tighten with the basin wrench until firm — do not over-tighten on plastic nuts or you risk cracking them. Wrap two or three turns of PTFE tape clockwise around the male thread on each hose tail before connecting the supply hoses, and tighten with a spanner — snug but not forced.
- 5
Restore water, check for leaks, and test
Slowly reopen the isolation valves a quarter-turn and watch every connection point for drips. Run the tap on cold first, then hot, checking under the sink with a torch throughout. A tiny weep at a compression fitting usually means one more quarter-turn on the spanner; a weep at a threaded connection means isolating again, adding more PTFE tape, and reassembling. Once everything is dry, run the tap through its full hot-cold range and check that the flow is strong and the spout pivots freely. Dispose of the old tap at a local municipal recycling point (ΚΔΑΥ) — brass fittings are accepted as scrap metal in most Greek municipalities.
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FAQ
- My old tap has no isolation valves under the sink. What should I do?
- You will need to close the main stopcock for the property before starting. In Greek apartments this is often in a locked riser cupboard on the landing — ask your building manager. Use this opportunity to have a plumber install inline isolation valves while the supply is down; they cost very little and make every future maintenance job far easier.
- The locking nut under my sink will not budge. How do I loosen it?
- Apply a generous amount of penetrating lubricant (such as WD-40 or a dedicated rust solvent) and leave it for 15–30 minutes. Use a basin wrench rather than an adjustable spanner — the ratcheting head gives real mechanical advantage in tight spaces. If the nut is still frozen, a strap wrench around the tap body while holding the nut can break the bond. As a last resort, a plumber can use a nut splitter to cut the nut off without damaging the sink.
- Does the water pressure in Greece affect which tap I can buy?
- Yes. Mains-fed apartments in Athens and most urban areas run at 2–4 bar, which suits any standard mixer tap. Properties on islands or at altitude that rely on a gravity-fed roof tank often run at less than 1 bar. Always check the manufacturer's minimum pressure rating on the box — some ceramic cartridges need at least 0.5 bar to seal correctly, and low pressure can cause a tap to drip from the moment it is installed. If your pressure is borderline, choose a tap rated for low-pressure or gravity-fed systems.