Does your new boiler quote need a condensate pump?

A new boiler does not automatically need a condensate pump. The answer depends on whether its condensate can reach a suitable drain by gravity. Before accepting a pump as an extra, ask the installer to explain the route, the alternatives and what the complete installation includes.

This matters when replacing a boiler in a difficult position or choosing a new location. A short line saying “condensate pump included” tells you the proposed equipment, but leaves several decisions unanswered.

What is the pump dealing with?

A condensing boiler produces slightly acidic wastewater called condensate. That needs a suitable drainage route. It is separate from the water circulating through your radiators: a condensate pump is not an upgrade to heating performance or shower pressure.

Worcester Bosch recommends an internal waste connection to reduce exposure to freezing. A blocked condensate route can interrupt boiler operation, so drainage deserves attention while the installation is being planned.

Source: Worcester Bosch: quick guide to condensate

Ask for the drainage options in order

HHIC’s installer guidance prioritises an internal gravity connection. Where that is impractical, it specifies a condensate pump to a suitable internal discharge point. External drainage is considered when internal gravity and pumped connections are impractical. The chosen boiler’s instructions also apply.

Ask which physical constraint rules out gravity: a higher drain connection, an obstructed route or an impractically long run. A pump may make sense, but “we always fit one” does not explain your home.

Source: HHIC condensate discharge guide, issue 3.0 (November 2023), pages 3, 8–9

Compare the whole job, not the accessory

Use this worksheet with each installer. These are questions for a surveyed quote, not instructions for designing or fitting drainage yourself.

Why the exact pump and access matter

A generic description is not enough to verify suitability. For example, Sauermann’s Si-82 family instructions give different flow capacities for combinations of lift height and pipe length, alongside condensate temperature and acidity limits. That illustrates why the installer needs to select for the actual route rather than a single advertised maximum.

The same instructions cover safety-switch testing and periodic maintenance. They are an example, not a specification for every pump. Ask for the manual for the model offered, the commissioning handover and an explanation of what its failure protection does. Do not assume the boiler guarantee covers the separate pump.

Source: Sauermann Si-82 / SI1800 / SI-1801 instructions, edition 23/01

A two-quote example

Imagine two installers propose the same replacement boiler in a utility room. Quote A includes a pump but leaves its location, wiring and future access unspecified. Quote B includes a longer gravity route through a cupboard and states who will restore the cupboard afterwards. This is an illustrative comparison, not a real customer case or a price benchmark.

Neither description alone proves which option is right. Ask A to complete the equipment and aftercare details. Ask B to confirm the proposed route is suitable and fully included. Then compare complete totals and the practical effect on your room.

If a third option moves the boiler closer to a suitable drain, have the installer explain the effect on the rest of the job too. Solving drainage alone does not settle the flue, gas supply or access requirements.

If the quote keeps an existing outside pipe

Ask the installer to assess the existing route rather than assume it can be reused. HHIC’s guidance explicitly calls for checking existing pipework and considering freezing downstream of a connection. Its guidance also warns that extreme prolonged cold can still defeat precautions.

The useful answer on a quote is what will be retained, what will change and why. A promise that the pipe “will never freeze” is less useful than a documented assessment.

Source: HHIC condensate discharge guide, issue 3.0 (November 2023), pages 3, 8–9

Settle the scope before booking

Send the same worksheet to each installer, along with the current and proposed boiler locations. Get any assumptions or exclusions clarified in writing before agreeing the work. Gas boiler installation must be carried out by a Gas Safe registered engineer qualified for the job; this guide is for comparing their proposals.

Boiler Comparisons introduces homeowners to independent installers for installation and replacement quotes. We do not install boilers ourselves, and availability depends on your postcode. Include the drainage question in your enquiry so each installer can assess it as part of the whole job.

Source: HSE: gas safety for homeowners