Why Does Hot Water Have Low Pressure and How to Fix It?
If cold water flows fine but hot water has no power, the problem lies in your water heater, boiler, or pipes. We explain the causes.
Reviewed by Javier Romero — Certified Technician
Approved by supervisor Rafael Casas de las Peñas Del Corral
Stepping into the shower expecting a strong blast of hot water and finding a weak trickle is frustrating. If the cold water in your Madrid home has good pressure, but the hot water does not, the problem is clearly isolated to your domestic hot water (DHW) circuit.
### Main causes of low hot water pressure
- 1.Limescale buildup in the heater or boiler: In areas with hard water, limescale accumulates in the boiler's heat exchangers or on the electric heater's elements, narrowing the water passage until it's almost blocked.
- 2.Clogged tap filters: Sometimes the problem is as simple as the aerators (the little piece at the tip of the tap) being full of tiny limescale stones.
- 3.Partially closed shut-off valve: Check the cold water inlet valve to your heater. If it's not fully open, not enough water will enter for it to come out hot with force.
- 4.Old rusted pipes: If your house has old galvanized iron pipes, rust accumulates inside, drastically reducing the flow rate over the years.
### What can you do? The first step is to unscrew the filter from the shower or sink tap and clean it with vinegar. If, after removing it, the hot water still comes out weakly, the problem is in the equipment or the wall pipes.
Do not attempt to dismantle your boiler or electric water heater without knowledge, as you are dealing with water, electricity, or gas simultaneously.
Tired of showering under a trickle of water? Contact PowerPro Madrid. Call us or send a WhatsApp; our plumbers will locate the blockage and restore pressure to your shower.
