Vaillant ecoFIT Pure Boiler Installation in Fulham, SW6 — Compact, High-Efficiency Upgrade

A residential property in Fulham, SW6 needed a full boiler replacement. The existing unit was old, inefficient, and housed in a tight cupboard space. Ralf installed a Vaillant ecoFIT pure — one of the most compact high-efficiency combi boilers available — completing the full boiler installation in one day.

Why the Vaillant ecoFIT pure suits London flats and cupboards

Space is one of the defining constraints of London housing. Flats, maisonettes, and Victorian terraces throughout Fulham, SW6 and the wider South West London postcode were built with cupboard spaces designed around boiler technology from decades ago. When those original units are replaced, the new boiler needs to fit within the same footprint — or smaller.

The Vaillant ecoFIT pure is one of the smallest full-output combi boilers available in the UK market. At 720mm high, 400mm wide, and 338mm deep, it fits into cupboard spaces that would be too tight for older or larger replacement models. Despite its compact dimensions, it is available in outputs from 25kW to 35kW — covering everything from a single-bathroom studio flat to a multi-room family home with higher hot water demand.

This combination of compact size and full heating output makes the ecoFIT pure the most frequently specified boiler in Pristine Gas Ltd’s London installations — not because of any commercial arrangement, but because it consistently solves the space constraint that other models cannot.

What was included in this installation

Ralf arrived in the morning and completed the full replacement within the day.

The old boiler was isolated, drained, disconnected, and removed from the cupboard. The wall was cleaned and prepared before the new ecoFIT pure was mounted. Copper pipework drops were installed in parallel runs and secured with pipe clips — Ralf uses copper as standard for all boiler connections rather than plastic push-fit, for durability and for the cleaner finish inside a cupboard.

The system was thoroughly flushed to remove any sludge and debris from the existing pipework before the new boiler was connected. A Vaillant magnetic system filter was fitted on the return to capture residual particles and protect the new heat exchanger going forward. The smart thermostat was installed, paired to the boiler, and confirmed working. Every radiator in the property was tested for heat output and the system was balanced. The Gas Safe installation certificate was issued and handed over before Ralf left.

An annual boiler service is required each year to maintain the Vaillant manufacturer warranty. Ralf explains this at handover so the homeowner knows what to book and when.

A-rated efficiency — what it means in practice

The Vaillant ecoFIT pure carries an ErP A-rating, indicating efficiency of 92% or above under standard operating conditions. For comparison, a G-rated boiler — common in London properties last upgraded before 2005 — typically operates at around 65 to 70% efficiency.

The practical consequence is direct and measurable. A modern A-rated condensing boiler extracts significantly more useful heat from every cubic metre of gas it burns. The difference between a 68% efficient unit and a 92% efficient replacement translates into a meaningful reduction in gas consumption each year. For many London homeowners, the saving in annual running costs covers a substantial portion of the installation cost over the boiler’s working life.

For landlords and homeowners planning to sell, a new A-rated boiler also improves the property’s EPC rating. As minimum EPC thresholds for rental properties continue to tighten under current legislation, replacing an old G-rated boiler is one of the more straightforward ways to improve an EPC score without major structural work.

Cupboard boiler installations — getting the clearances right

Fitting a boiler inside a cupboard requires careful attention to the service clearances specified by both Gas Safe regulations and the boiler manufacturer. Vaillant specifies minimum clearances on all four sides of the ecoFIT pure — above, below, left, right, and in front of the unit — to allow safe operation and access for annual servicing.

When these clearances are not met, the consequences range from reduced boiler performance to premature component failure, and in some cases the boiler’s safety systems will lock it out entirely. Equally importantly, an annual service cannot be properly carried out if the engineer cannot safely access the boiler’s controls and serviceable components — which means the manufacturer warranty may be invalidated at the first service visit.

Ralf measures and confirms all clearances before mounting any boiler inside a cupboard. If the existing cupboard dimensions do not allow the required clearances for the chosen model, he will advise on the options — which may include a different boiler model with a smaller footprint, minor modifications to the cupboard, or in rare cases a different installation location — before any work begins. This is confirmed at the quotation stage, not discovered partway through an installation.

Covering Fulham SW6 and South West London

Pristine Gas Ltd is based in Holborn, WC1N and covers all South West London postcodes including SW6, SW15, and SE11. For boiler installation and replacement across South West London, most jobs can be arranged with next-day availability.

For a free, no-obligation boiler installation quote in Fulham, SW6 or anywhere across South West London, call 07472 251465. Ralf will discuss your property, current system, and hot water demand and give you a fixed price before any work is booked.

Related: Power Flush and Radiator Service in Kensal Town, W10 — why a clean system before installation matters