The BWT Perla Silk PS25UK is a 25-litre ion-exchange water softener sized for households of up to 10 people, with a nominal flow of 1,680 l/h to EN 14743 and a 24 kg salt reservoir. It meters what you actually use and regenerates in proportion, so salt and water go on softening rather than on a fixed timer. This is the standard (non-Wi-Fi) version, which can also run on domestic batteries for up to three months if there is no socket nearby.
25 L resinUp to 10 peopleTested to EN 14743Battery back-up optionTablet only salt22 mm kit & bypass included
1,680 l/h
Nominal flow (EN 14743)
EN 14743
Tested and compliant
5–50 l/min
Operating flow range
5 yr / 2 yr
Parts / labour @home
Applications & suitability
Where it goes
On the incoming cold main, downstream of the stopcock, meter and any pre-filter, in a utility room, plant room or garage. At 803 mm tall it is too tall for a standard kitchen base unit. It needs a waste pipe, an overflow route to outside and a 230 V socket.
Typical job
Replacing scale-fouled kettles, showerheads and cylinder elements in a multi-occupancy house, HMO, guest house or small commercial premises where demand runs all day. Sizing is based on average use at 300 ppm hardness.
Works with / replaces
Same unit as the Wi-Fi model without the app link. Supplied with 22 mm high-flow hoses, the Uniconnect block and bypass, so it swaps for most existing 22 mm-connected softeners. Runs on BWT Care Cube tablet salt; block salt is not supported on this size.
When not to choose this
This is the largest Perla Silk; larger commercial demand needs a duplex or commercial softener. You want app monitoring and salt alerts: choose the Wi-Fi version instead. You must fit inside a kitchen base unit: at 803 mm this will not, so look at the PS10 or PS15. You want to use block salt: this size takes tablet salt only. Incoming pressure above 5 bar needs a pressure-reducing valve first, and water above 30 °C must not enter the unit.
Key specifications
| Identity |
| Brand |
BWT |
| Model |
PS25UK |
| Household size |
Up to 10 people (average use at 300 ppm) |
| Performance |
| Resin volume |
25 L |
| Flow rate |
5–50 l/min operating; 80 l/min max with straight connectors; 1,680 l/h nominal (EN 14743) |
| Pressure drop at nominal flow |
1.0 bar |
| Min operating pressure |
1.7 bar |
| Max working pressure |
5 bar |
| Max working temperature |
30 °C water (5–40 °C ambient) |
| Salt & connections |
| Salt type |
Tablet only |
| Salt reservoir capacity |
24 kg |
| Connection size |
¾″ BSP (DN20) with 22 mm high-flow hoses and Uniconnect block |
| Connection height |
622 mm (overflow 527 mm) |
| Electrical & control |
| Power supply |
230 V mains via 12 V DC plug transformer; domestic battery operation up to 3 months (batteries not supplied) |
| Operation |
Automatic proportional regeneration, blending valve, brine safety valve, memory on power cut |
| Physical |
| Dimensions (H × W × D) |
803 × 276 × 470 mm |
| Weight |
70 kg approx. (operating) |
| Standard |
EN 14743 |
| Warranty |
5 years parts, 2 years labour @home (6-year upgrade available from BWT within 60 days of install) |
Installation & compatibility
Fit on the cold main downstream of the stopcock, meter and any protective filter, using the supplied Uniconnect block, bypass and 22 mm high-flow hoses; you also need a tundish or standpipe for the drain, an overflow to outside and a 230 V socket. Installation must comply with the Water Supply (Water Fittings) Regulations 1999, and your water supplier may expect a separate unsoftened drinking-water tap, so a competent plumber is recommended. Once fitted, BWT includes a free @home commissioning visit to set hardness and salt type.
Related & next steps
Smaller home? PS20UK
Same range, 20 L resin, up to 8 people.
View
Want app control? PS25UKWF
Same softener, Wi-Fi enabled with the BWT Best Water Home app.
View
Keep it fed: Care Cube tablet salt 25 kg
BWT’s own tablet salt, suitable for every Perla Silk size.
Add salt
Ideal for
A multi-occupancy house, HMO, guest house or small commercial premises where demand runs all day, in a hard-water area, where you want a softener that regenerates on demand rather than on a clock and keeps working through a power cut. Available for next-day national delivery or click & collect from our Reading trade counter.
At GetPlumb, we strive to provide reliable and cost-effective delivery options to our customers. Please review our shipping policy below.
🆓 Free Local Delivery (Orders £100 & above)
We offer FREE delivery on orders £100 or more
for selected local areas.
Eligible Postcodes Include:
- RG*
- SL*
- OX10*, OX11*, OX49*
- HP1*, HP3*, HP8*, HP9*, HP10*, HP11*, HP12*, HP13*, HP14*
- WD*, HA*, UB*, TW*, KT*
- W1* – W9*
- NW*, SW*
Delivery Time: 2–4 working days
Shipping Cost: £0.00
📦 Standard Shipping (Weight-Based Rates)
For orders that do not qualify for free delivery, standard
shipping rates apply based on total cart weight.
- For cart weight between 0–2 kg, the shipping cost is £4.50 with a delivery time of 2–4 working days.
- For cart weight between 2–24 kg, the shipping cost is £9.99 with a delivery time of 2–4 working days.
- For cart weight between 24 kg and above, the shipping cost is £60 with a delivery time of 2–4 working days.
🧱 Block Salt (Harvey’s) – Unit-Based Shipping
This rate applies only to Harvey’s block salt products.
- £7.99 is charged for every 3 items.
- The charge increases by £7.99 for each additional set of 3 items.
Examples:
- 1–3 items → £7.99
- 4–6 items → £15.98
- 7–9 items → £23.97
Delivery Time: 2–4 working days
📏 Large / Long Items (Length-Based Shipping)
For oversized items where the product length is 1.5 metres or more:
Conditions:
- Product length ≥ 1.5 m
- Cart weight ≤ 40 kg
Shipping Cost: £18.00 (flat rate)
Delivery Time: 2–4 working days
Collection from Store
Customers can also choose to collect their order from our store in
Reading, UK, at no additional charge. For any questions regarding shipping, please contact our support team at online@getplumb.co.uk.
