Guides · Showers
Bristan 2.0 bar twin-ended shower pump review, researched
Research-based review of the Bristan ST PUMP20TN positive-head twin shower pump, with official specifications, installation limits and alternatives.
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Research note: We haven't had or installed this pump. This review is based on Bristan's product page, technical data and fitting instructions, not hands-on testing.
We haven't tested this. Figures are as the maker states them (checked 13 November 2026).
Our verdict
The ST PUMP20TN is a 2.0 bar twin-impeller pump for boosting hot and cold to a mixer shower on a positive-head, vented stored-water system. Bristan's data sheet rates it at 35 L/min and its fitting guide requires at least 0.8 L/min gravity flow through every outlet being pumped. It is a plausible middle option when 1.5 bar is too little, but the intermittent rating on the data sheet — 30 minutes on, 30 minutes off — and system requirements matter more than the headline pressure.
Bristan impeller twin ended, 2.0 bar. Confirm the model code ST PUMP20TN and positive-head system before ordering.
What it is
This is a single-speed, twin-impeller peripheral pump: one impeller boosts stored hot and the other stored cold. Bristan says it is for gravity-fed systems and mixer showers. It needs natural flow to trigger its flow switches, so it is not the negative-head model.
Key specifications
Official figures from the Bristan product page, technical data sheet and fitting instructions, checked 14 November 2026.
| Specification | Bristan figure |
|---|---|
| Product code/type | ST PUMP20TN; single-speed twin impeller, positive head |
| Rating | 2.0 bar; 35 L/min; 19 m closed-valve head on data sheet |
| Start flow | More than 0.8 L/min through each outlet being pumped |
| Electrical | 230 V AC; 420 W; 5 A fuse; 1.5 m cable |
| Duty | 30 minutes on / 30 minutes off on the product data sheet |
| Water temperature | 4°C minimum; 65°C maximum |
| Connections | 15 mm push-fit flexible hoses; four supplied |
| WRAS | 250304731, expiry 31 March 2030 |
| Warranty | 3 years on the product badge/data sheet |
The current product-page feature copy also mentions “5-year parts and 1-year labour”, while its badge and technical data say three years. We have not resolved that conflict: ask Bristan which guarantee applies to the unit and purchase date.
Installation and safety
Bristan says the pump must not be connected directly to the mains and the plumbing must be installed by a qualified person. Its electrical installation must also be done by a qualified person, to current regulations, with a 30 mA RCD in the supply circuit.
The guide calls for adequate hot and cold storage, 22 mm pipework for optimum performance, a dedicated air-free cold supply, the correct cylinder take-off, an inline strainer and a position close to and below the hot-water take-off. The pump must be primed and must not run dry. It is permanently connected through a double-pole switched fused spur, not the boiler or immersion circuit.
Use a qualified plumber and qualified electrician. This is not a DIY installation guide and not gas advice. See hiring a plumber and WRAS and water regulations.
Owner evidence
We did not find a readable body of model-specific owner reviews in the sources used, so we have not claimed a consensus. Bristan's “low noise” wording is marketing supported by anti-vibration feet, not a Leatmere noise test.
Pros and cons
Pros: boosts hot and cold; current WRAS certificate; published flow and electrical figures; anti-vibration feet and four hoses; three-year badge.
Cons: positive head only; intermittent duty on the data sheet; installation is exacting; guarantee wording conflicts on Bristan's current page.
Who it suits — and who should skip it
It may suit a positive-head mixer shower on a correctly sized vented cylinder/cistern system. Skip it for negative head, a combi, an unvented cylinder, direct mains connection or sustained demand outside its duty rating. Read shower pump sizing first.
Alternatives
For universal head, see the Bristan negative-head twin review. For one supply, see the Bristan single-ended review. The Salamander CT75 Xtra is another 2.0 bar positive-head twin. Also compare shower pumps compared, noise and mains boosters.
How we researched this
We read Bristan's current product page, product data sheet and installation manual, plus the Wickes listing, on 14 November 2026. We have not owned, installed or tested the pump.
Sources
Bristan product page; technical data; fitting instructions; Wickes listing. Opened 14 November 2026.