Before you buy an older property in Spain, check water pressure at several taps, the condition of visible pipework, under every sink, damp patches, the toilets, how the drains run, the hot water, the boiler and gas installation, the stopcock, and the outdoor taps and irrigation.
Most of it you can do yourself in twenty minutes at a second viewing. The checklist below is in the order it makes sense to walk the property.
In this article
Why the plumbing matters in an older Spanish property
Older Spanish properties are often better built than people expect. The problem is rarely the original construction: it is thirty or forty years of patch repairs, part-renovations and hard water on top of it.
Modern installations here are built to the Código Técnico de la Edificación — HS 4 covers water supply, HS 5 covers wastewater, and there are requirements for protection against humidity. A property that predates those requirements may be perfectly sound, but it was not built to them, and nobody will tell you that at a viewing.
None of what follows means you should walk away. It means you should know what you are buying before you agree a price.
The checklist at a glance
| Area | What to look for | Por qué es importante |
|---|---|---|
| Water pressure | Weak flow from several taps | Scale, old pipes or a supply problem |
| Visible pipes | Rust, corrosion, staining, old repairs | Ageing pipework |
| Under sinks | Drips, damp wood, mould, smells | The commonest place a leak hides |
| Bathrooms | Slow drains, loose toilets, poor flushing | Waste pipe or cistern faults |
| Kitchen | Sink drainage, appliance hoses, leaks | A busy area with many connections |
| Hot water | No hot water, noise, rust, leaks | May need repair or replacement |
| Boiler | Odd noises, pressure loss, error codes | Heating system faults |
| Drains | Smells, gurgling, slow flow | A blockage or a vent problem |
| Stopcock | Where it is, and whether it works | It is what saves you in a leak |
| Outdoors | Wet patches, irrigation leaks, old taps | Almost always missed on a viewing |
The eleven checks in detail
1. Check water pressure in several taps
Test
Run the kitchen tap, a bathroom tap, the shower and an outdoor tap — first one at a time, then two together.
Red flag
Weak flow at several fixtures at once.
One weak tap is usually local: a blocked aerator, a partly closed valve. Several weak fixtures point at the system — limescale, old or narrow pipes, weak supply pressure, a faulty pressure regulator, or a hidden leak.
2. Look for old, corroded or mixed pipework
Test
Look at every run of pipe you can actually see — under sinks, in the utility room, the garage, around the boiler.
Red flag
- rust, or green and white staining on copper;
- corroded joints, pipes poorly supported;
- visible patch repairs, pipes entering a damp wall;
- valves too stiff to turn.
One old pipe is not a reason to walk away. Repeated patches along the same run are, and so is a mix of three different materials joined together. Our guide on whether to repair or replace old plumbing pipes goes into where the line falls.
3. Inspect under the sinks and inside the cabinets
Test
Open every cabinet — kitchen, bathrooms, utility, vanity units — and look at the dishwasher and washing machine connections.
Red flag
- swollen or darkened cabinet bases;
- mould, water stains, a musty smell;
- corrosion on fittings, a dripping trap;
- a loose waste pipe.
4. Check for damp patches and hidden leaks
Test
Walls near bathrooms and kitchens, floors above bathrooms, around the water heater or boiler, walls with pipes buried in them, and terrace or outdoor tap connections.
Red flag
Damp with no obvious cause — and anyone telling you it is only cosmetic.
A leak under a floor slab shows up as a warm or damp patch long before anything else appears, and detecting a slab leak early is the difference between a repair and a renovation.
5. Test every toilet
Test
Flush each one, then wait and watch what happens after the flush finishes.
Red flag
- water still running after the flush;
- a weak flush or slow refill;
- a base that moves, or water around the foot;
- smells at floor level, cracks in the cistern or pan.
A toilet that keeps running is usually cheap to fix. A toilet that moves is not — that is the seal, and often the floor underneath it.
6. Check the drains for slow flow, gurgling and smells
Test
Fill and empty basins, showers, baths and the kitchen sink. Listen as they empty.
Red flag
- slow drainage or gurgling;
- a sewage or rotten-egg smell;
- water backing up;
- several drains affected at once.
Several drains at once points at the main run rather than one trap. Worth reading on what the smells actually mean: bad smells coming from drains y how to prevent drain clogs.
7. Test hot water performance properly
Test
Time how long hot water takes to arrive, then leave it running for several minutes.
Red flag
- slow to arrive, or never properly hot;
- temperature swings while running;
- runs out quickly, or the unit is noisy;
- leaks, rust or staining near it.
Poor hot water can mean maintenance, a repair or a replacement — see our hot water systems service.
8. Check the boiler, the heating and the gas installation
Test
Ask for the service history and inspection records antes de you look at the boiler itself. What is missing from the paperwork tells you more than the unit does.
Red flag
- no records at all;
- pressure that drops, or error codes;
- noises, leaks or rust, poor hot water;
- improvised ventilation or DIY modifications.
Noise on its own can be air, pressure, limescale, poor circulation or a worn component — what a noisy boiler usually means. Gas work is not a DIY area in Spain and needs a qualified installer: see instalaciones de gas.
9. Find the stopcock before you buy — and turn it
Test
Ask to be shown the internal stopcock, then actually turn it. Check for an external stopcock or meter box too, and for isolation valves on the toilets and appliances.
Red flag
- nobody knows where it is;
- it will not turn;
- it turns but does not fully stop the water.
On the day a pipe bursts, this is the single most important object in the property. If you only do one thing on this list, do this one — what a stopcock is and why every owner should know where it is.
10. Check outdoor taps, irrigation and pool-area plumbing
Test
Outdoor taps, the irrigation system, pool water connections, the pump room, external pipework, the meter box, terrace drains, outdoor showers.
Red flag
- wet soil with no reason for it;
- a dripping tap or a cracked pipe;
- rusty fittings;
- damp at the base of an exterior wall.
Outside leaks run for months because nobody sees them from indoors — they show up on the bill instead. If there is a pool, see pools and related water systems.
11. Ask what the renovations actually replaced
Test
Ask when the bathrooms were renovated, whether the pipework was replaced or only the fixtures, whether the kitchen plumbing was updated, and whether the boiler or water heater was changed.
Red flag
A beautifully renovated bathroom with the original pipes still behind the wall.
This is the most common trap in an older Spanish property: the visible half was replaced and the buried half was not. Ask for invoices, guarantees and who did the work. Work done by a licensed professional comes with paperwork; work that has no paperwork usually did not.
How serious is what you found?
Not everything on the list is a reason to renegotiate. This is roughly how the common findings rank.
| Warning sign | Possible meaning | Risk |
|---|---|---|
| One dripping tap | Worn washer, cartridge or valve | Low |
| Low pressure in one tap | Aerator, valve or local pipe | Low |
| Damp under a sink | Local leak or waste problem | Medium |
| Bad drain smells | Dry trap, blockage, vent or sewer gas | Medium |
| Running toilet | Fill valve, seal or flush mechanism | Medium |
| Low pressure throughout | Scale, old pipes, supply issue or leak | High |
| No hay agua caliente | Heater, boiler, power or gas | High |
| Rusty water | Corroded pipes or water heater | High |
| Boiler pressure dropping | Leak, valve or system problem | High |
| Meter moving with taps off | A hidden leak somewhere | High |
| Damp floor, no clear cause | Hidden leak or slab leak | High |
| Stopcock stuck | Emergency shut-off may fail | High |
The one test that catches most of the expensive problems: turn off every tap and appliance in the property, then go and look at the water meter. If it is still moving, water is leaving the system somewhere you cannot see. Do this before you sign anything.
Questions to ask the seller or agent
Take this list to the viewing. The answers matter, but so does whether anyone can answer at all.
- When was the plumbing last inspected?
- Have any pipes been replaced, and which?
- Is there a history of leaks or damp?
- Where is the stopcock?
- Does the stopcock actually work?
- When was the boiler last serviced?
- How old is the water heater?
- Are there gas inspection or service records?
- Are there recurring drain smells or blockages?
- Has the property been empty for long periods?
- Is there a water treatment system?
- Are there warranties for recent plumbing work?
What is different about Costa Blanca properties
Two things set properties here apart from the generic advice you will read about buying an old house.
Hard water
- limescale narrowing pipes and reducing flow;
- taps, shower heads and valves furring up;
- boilers, heaters and appliances losing efficiency;
- higher maintenance over the life of the installation.
Properties left empty
- drain traps drying out, so smells come back in;
- a leak running for months with nobody there;
- stopcocks and isolation valves seizing up;
- boilers and heaters used only part of the year.
On top of those: older villas with mixed pipework, renovated bathrooms hiding original pipes, outdoor taps and irrigation leaks, pool-area plumbing, and hidden leaks that only get discovered after the purchase. Hard water in particular is not a cosmetic issue here — see how hard water affects pipes, boilers and appliances in Costa Blanca homes.
Read next Plumbing maintenance checklist for holiday homes in Calpe and the Costa BlancaIs a plumbing inspection worth it before you buy?
It is worth it when the property is older, has been renovated, has been standing empty, shows damp or low pressure anywhere, or comes with no boiler and plumbing records. Against the price of a property, an inspection is a rounding error; against the cost of repiping a villa after completion, it is nothing.
What a plumber checks that you cannot:
- visible pipework, and how it has been joined and supported;
- the stopcock and isolation valves, under test;
- water pressure measured rather than guessed;
- toilets, cisterns and drainage performance;
- sink and appliance connections;
- the boiler and water heater area;
- signs of leaks, and limescale symptoms;
- outdoor water points;
- whether further leak detection is needed before you commit.
That last point is the one that matters most. A plumber’s job at this stage is not to fix anything — it is to tell you whether what you can see is the whole problem or the start of one.
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Frequently Asked Questions
What plumbing problems should I check before buying an older property in Spain?
Water pressure at several taps, the condition of visible pipework, under every sink, damp patches and hidden leaks, the toilets, how the drains run, hot water performance, the boiler and gas installation, the stopcock, the outdoor taps and irrigation, and what previous renovations actually replaced.
Should I get a plumbing inspection before buying a house in Spain?
Yes, particularly if the property is older, has been renovated, has stood empty, shows damp or low pressure, or has no boiler and plumbing maintenance records.
Can old pipes cause problems after buying a property?
Yes. They can cause leaks, low pressure, rusty water, damp and repeated repairs. Patched or mixed pipework tends to become less reliable over time, not more.
How do I know if a property has a hidden leak?
Damp patches, musty smells, low pressure, the sound of running water, a water meter that moves when every tap is off, a warm area of floor, or unexplained stains.
Why does hard water matter when buying on the Costa Blanca?
Hard water builds limescale in pipes, taps, boilers, heaters and appliances. It reduces flow, lowers efficiency and raises maintenance costs over the life of the installation.
Where is the stopcock in an older Spanish property?
Usually near where the water supply enters the property: under the kitchen sink, by the meter, in a utility area, a garage, a bathroom cupboard, or an external meter box.
Who can check the plumbing before I buy on the Costa Blanca?
A qualified plumber can inspect pipework, pressure, drains, toilets, valves, the boiler, the hot water system and the signs of hidden leaks before you commit to the purchase.
Buying a property and want the plumbing checked first?
We inspect plumbing for buyers before completion — pipework, pressure, drains, boiler, hot water and the signs of hidden leaks. Better to know now than after the keys change hands.
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