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Secondary return bronze pump

Updated: 22 October 2026

The ensuite tap runs cold for a bucketful while the kitchen is fine, or the cylinder diagram shows a small bronze pump you do not yet understand. A secondary return keeps hot water near distant outlets so you waste less water waiting. The pump sits with the cylinder tappings, a non-return valve, insulation, controls and sometimes a flow-regulating valve. Worcester Bosch TB0050 is the UK reference sketch. Six bronze circulators are on the [bronze circulating pump comparison](/hub/heating/bronze-circulating-pump). Peter F. compared amazon.co.uk listings and public UK guidance. There was no lab test. A qualifying purchase can earn a commission at no extra cost to you.

The ensuite tap runs cold for a bucketful while the kitchen is fine, or the cylinder diagram shows a small bronze pump you do not yet understand.

Our top picks

Hanicks Hanicks 97549426

Best overall

Hanicks Hanicks 97549426
10.0/10about £140.00
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Trident Trident TP256-130BR

Best value

Trident Trident TP256-130BR
8.2/10about £89.99
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Unvented Components Europe Unvented Components Europe GPD25-6SQ-130

Rank 3

Unvented Components Europe Unvented Components Europe GPD25-6SQ-130
0.0/10about £94.77
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On this page
  1. 1.What a secondary return solves
  2. 2.Loop components in order
  3. 3.How the pumps in this comparison are sized
  4. 4.Insulation, timing and energy
  5. 5.When replacing the pump is not enough

What a secondary return solves

A dead-leg is a pipe run long enough that you dump water while heat sits in the pipe, or cools and repeats. A secondary circuit takes hot water past the remote branches and returns it toward the cylinder through a dedicated pipe and pump. You save water at the tap. You spend energy if the pump runs all day on high speed with no insulation or timer. TB0050 aims at reliable hot water without redesigning the whole system. Radiator problems are a different circuit. This loop is potable, which is why the pump is bronze, or an approved stainless model, rather than cast iron.

Loop components in order

Flow leaves the cylinder outlet, passes tees to basins and showers, then returns. A non-return valve stops hot water pushing into the cold supply. The bronze pump sits on the return near the cylinder, with the cast arrow matching the manufacturer. Isolating valves let you service it without draining the house. Insulation on the return, and often the flow, limits standing loss. TB0050 shows that pipework insulated. Bare copper in a loft eats the saving. A flow-regulating valve can stop the pump slamming zones open. Controls may be a timer, a cylinder stat or a demand switch. Large cylinders may have secondary bosses. Smaller ones use swept tees. The cylinder manual beats a generic diagram.
Hanicks Hanicks 97549426

Testsieger

Hanicks Hanicks 97549426
10.0/10about £140.00
View offer

How the pumps in this comparison are sized

The amazon.co.uk rows cluster near 6 m head and, where printed, 57–65 litres per minute, with 130 mm on the clearest listing, the GPD25. That matches the Archergas DHW15 class installers quote, even when the brand differs. Three speeds let you turn down after install. Extra head does not fix a return the size of a straw or a valve pinned shut. Match 1½ inch BSP unions to the tails. Hanicks prints 65 L/min and WRAS in the title. SE60B prints 57 L/min. Trident is about £89.99 with fewer dimensions on the card. Named picks are on best bronze circulating pump.

Insulation, timing and energy

Running a secondary pump all day on speed 3 warms the cupboard and the loft pipe while you sleep. TB0050 and common installer practice favour timed operation, or temperature-aware control, so the loop runs when people actually shower. Insulation is not optional on a long return. Pump-only purchases disappoint when that pipe is left bare. The energy cost is smaller than a main heating pump and it is never zero. Read the EEI on the nameplate if paperwork matters. Legionella control in commercial recirculation depends on holding return temperatures and on monitoring. HSG274 Part 2 is the context for care homes and similar buildings. A domestic home should still avoid lukewarm stagnant lengths by a sensible run strategy. The pump does not replace that.

When replacing the pump is not enough

If a new bronze unit is quiet and the ensuite still runs cold, check the non-return valve orientation, the bypass tees, trapped air, and whether the loop was ever designed for the extension you built. Insulation stripped in the loft behaves like a new uninsulated run. Landlords balancing water saving against a legionella policy need a written strategy, not only a Hanicks box. Approval proof for that file is on WRAS approved bronze circulating pump. The mechanical swap is on how to install a bronze circulating pump.

Common questions

Why is the pump bronze and not cast iron?
Wetted parts contact potable hot water. Bronze, or an approved stainless pump on other models, matches domestic hot water hygiene expectations. Radiator iron bodies belong on heating loops.
Where on the cylinder does the return connect?
It depends on the cylinder size and the boss layout. Large cylinders may have dedicated secondary bosses. Smaller units use a prescribed tee arrangement. Use the manufacturer drawing for your model.
What does a non-return valve do in the loop?
It prevents reverse flow that could push hot water toward the cold supply, or upset the balance when pumps start and stop.
Must I insulate the return pipe?
Yes, if energy use or comfort is the goal. TB0050 shows insulated return pipework. A bare long run wastes the benefit you bought the pump for.
Should the pump run all day?
Usually not, if you are trying to limit domestic energy use. Time it to occupancy, or use the controls in the system design. Continuous running without a policy is a legionella and cost question in a regulated building.
Can a secondary return save water without wasting energy?
It can, when insulation, the speed setting and the timers line up. A pump-only swap without those pieces often disappoints.

Related pages

Bronze circulating pump buying guide

Bronze circulating pump

Best bronze circulating pump for a UK secondary loop

How to install a bronze circulating pump on a loop

WRAS approved bronze circulating pump: what counts

Sources

Public UK sources named below. amazon.co.uk prices, stars and review counts on these six listings were taken from the listing files. Page updated October 2026.

  1. Wilo UK: bronze vs stainless domestic hot water pumps (retrieved October 2026)
  2. Worcester Bosch TB0050 secondary circulation (retrieved October 2026)
  3. HSE HSG274 Part 2: hot and cold water systems (retrieved October 2026)
  4. Archergas DHW15 reference duty (retrieved October 2026)
  5. BritTherm bronze circulator use cases (retrieved October 2026)
  6. Approved Document G (2024 amendments) (retrieved October 2026)
  7. amazon.co.uk listings for the six retained pumps (retrieved October 2026)