The sound you stop noticing
You flush, and then there’s a soft hiss that never quite stops. Or the cistern refills for two seconds every ten minutes, on its own, for no reason.
That’s a fill valve that isn’t sealing. It’s the single most common plumbing fault in rented property on this coast, and it’s the one most often left alone until something worse happens.
Why it isn’t just wasted water
On mains water, a running toilet is a bill. On a community supply in an apartment block, it’s also a nuisance that a neighbour will eventually report.
But the real cost is what it does to the valve seat. A valve that trickles past its seal slowly scales up. What started as a five-euro part becomes a valve body, then a cistern issue, and in the worst case it overflows — because the fill valve never shuts off and the overflow can’t keep up. That’s when it goes through a ceiling into the flat below.
Greg has been called to more water-damage claims caused by a toilet than by any other single fitting.
What usually fails
The fill valve — the one that lets water in and should stop it. Scale on the seal, or a float that’s lost its adjustment.
The flush valve — the seal at the bottom that holds water in the cistern. If water trickles into the bowl continuously rather than the cistern refilling, it’s this one, not the fill valve.
Knowing which of the two it is saves a wasted visit. If the cistern refills by itself, it’s the fill valve. If the bowl has a constant trickle, it’s the flush valve.
Why it’s a same-day fix here
Because it’s the most common failure, Greg keeps reusable flush cartridges, fill valves and toilet connectors in the van. They’re the parts that fail on this coast, so they’re the parts he carries.
That’s the difference between a repair and a return visit: the part is already there, and a straightforward valve swap takes minutes rather than a second appointment.
What to check yourself first
Lift the lid and look at the water level. If it’s above the overflow mark, the float needs adjusting — sometimes a five-second fix. If it’s at the right level but the valve still runs, it’s the seal.
Don’t bend the arm to force it. On a scaled valve that just delays it, and it can crack the plastic.
If you manage the property from abroad
This is the fault to fix before it becomes an emergency. It’s cheap now, and it’s a ceiling stain later — and a ceiling stain in a rental is a compensation conversation, not a plumbing one.
Greg covers Marbella, Calahonda and the surrounding coast, and works with owners and property managers who aren’t on site. Send a photo of the inside of the cistern and he’ll tell you which part you need.
