Booster pumps fail in three ways. The motor seizes from limescale in the impeller chamber, the seals perish and the unit weeps from the pump head, or the pressure switch sticks and the pump runs continuously, overheats, and trips its thermal cut-out. On a typical London traditional system, a Salamander, Stuart Turner, or Grundfos pump sits next to the hot water cylinder or in an airing cupboard and feeds an upstairs bathroom from the cold-water storage tank in the loft. When the pump fails the shower runs to a trickle, the bath takes 25 minutes to fill, and the basin tap on the same circuit develops the same drop in flow within a few days as the impeller continues to degrade.
We replace booster pumps as a like-for-like swap where the system geometry is sound, and we upsize where the bathroom has been extended or the property now has two showers running off the same supply. Common replacements include the Salamander RSP CT Force, Stuart Turner Showermate Eco, and Grundfos NMT in single or twin-impeller form depending on whether the pump is feeding hot only, cold only, or both supplies together. Every install includes a vibration-dampening mount kit, flexible bellows on the inlets and outlets to isolate noise, a check valve on each supply, and a wired-in fused spur to the manufacturer's electrical specification. The unit is commissioned, leak-tested, and the bathroom run through a full hot-and-cold cycle before we leave.
Where this service applies
- Booster pump no longer starting on demand, motor seized or pressure switch failed
- Pump runs continuously even with no draw-off, sticking switch or check-valve failure
- Pump weeping at the casing or impeller chamber, perished mechanical seal
- Loud humming, grinding, or vibration through the floor when the pump starts
- Significant drop in shower flow over weeks, impeller degrading in hard water
- Upgrade from a single-impeller (cold-only) to a twin-impeller (hot and cold) following a bathroom extension
- Replacement of an out-of-warranty unit before a tenanted property re-let
- New installation to support a power shower or rainfall head on a gravity-fed system
- Whole-house cold-mains booster pump on a property with a documented weak supply
How we deliver
No surprises, no upselling. The exact path every job follows.
- 1
Diagnostic on the existing pump
We confirm the failure mode (motor, switch, seal, impeller) and check whether a manufacturer service kit will return reliable life or whether replacement is the correct call. Some Stuart Turner and Salamander units take economic seal kits, many do not. - 2
Pump specification and sizing
We match the replacement to the system: single-impeller for cold-only, twin-impeller for hot-and-cold, and rated bar pressure matched to the number of outlets and head height to the loft tank. - 3
Isolate and remove
Hot and cold supplies isolated at the dedicated service valves (fitted on every modern install) or at the cold-tank gate valve, electrical supply isolated at the fused spur, and the old pump lifted out cleanly. - 4
Mount and pipework on the new unit
Pump bedded on a manufacturer's vibration-dampening pad, flexible bellows fitted to the 22mm copper inlet and outlet tails to isolate noise, and new check valves installed on both supplies. - 5
Electrical connection
Pump wired to a dedicated 3-amp fused spur on its own RCD-protected circuit. Earth-bond verified. Where the existing supply does not meet the manufacturer's spec we upgrade the spur before energising. - 6
Prime, commission, and bleed
Supplies opened, pump primed under static head, and any trapped air bled at the bleed screws on the casing. Pump cycled three times under load before any panel or cabinet is reinstated. - 7
Performance test and warranty registration
Shower flow measured at the head, both hot and cold, before-and-after readings logged, and the manufacturer warranty registered on your behalf so the cover begins cleanly from the install date.