A mixer shower works the opposite way: it blends hot and plumbers merchants cold water drawn from the property's existing supply, whether that is a combination boiler, a vented cylinder, or an unvented cylinder, and its performance rides entirely on what that system can provide. On a property with an unvented cylinder or a combi boiler delivering strong, consistent mains pressure to both hot and cold, a mixer shower can perform very well, often better than an electric shower, because it is not limited by the kW-versus-flow trade-off that constrains instantaneous heating. On a property with a low-pressure vented cylinder fed from a loft tank, the same mixer shower may deliver disappointing pressure unless a pump is added to the system.
Plumb2U stocks immersion elements, thermostats and cylinder spares across the sizes trade buyers need to correct a capacity mismatch properly, at trade prices with next-day despatch, so the replacement part is the right one, not just the nearest one.
Flexible hoses connecting the unit to the water supply are the third recurring item, for the same reasons flexible hoses wear anywhere else in a plumbing system: material fatigue, pressure cycling, and simple age. A hose that is starting to weep or show wear at a fitting is a straightforward, low-cost replacement, and one worth catching before it becomes a bigger job.
For a trade buyer troubleshooting inconsistent hot water on an otherwise healthy system, checking the heater's rating against the cylinder's actual capacity is a faster diagnostic step than assuming a fault with the element itself. Matching the two properly, rather than replacing like-for-like from whatever failed, is usually what actually resolves the complaint.
Plumb2U stocks both braided and rubber flexible hoses across the sizes and ratings trade buyers need, at trade prices with next-day despatch, so the choice comes down to the job, not what happens to be on the shelf.
Here is the trade-off in practice. An electric shower heats mains water instantaneously as it passes through, the same principle as an instantaneous water heater, and the incoming cold-water temperature sets the starting point. In winter, mains water arrives colder, so the unit needs a bigger temperature rise to reach a comfortable shower temperature. To manage that rise within its rated kW, it has to reduce the flow rate passing through the element. That is why the same shower can feel noticeably weaker on a cold morning than it did in the summer: it is not faulty, it is doing exactly what its rating allows.