Is my boiler or heat pump brand Quiet Mark certified?

For a household, the badge answers one narrow question: is this particular listed model among the quieter units its maker sells? It does not give a sound figure. Quiet Mark does not publish decibel levels, a position stated on its own product pages and confirmed by a Welsh Government report on air source heat pump noise, which notes Quiet Mark assessing sound quality beyond the dB rating of products but not publishing dB levels³.

The practical consequence is that certification and declared sound data are two separate things. Every boiler and heat pump is acoustically tested before it comes to market, to specific ISO standards, with decibel levels declared and included on the energy label of each unit¹. That label, not the badge, is where a number lives.

How selective the certification is

The badge is deliberately scarce. Quiet Mark states that only the quietest 20% of any heating sub-category is eligible for certification, and that between only 10% and 20% of the quietest best performing products in a category are awarded it². Eligibility and award are therefore two different filters: a product can be in the quietest fifth of its category and still not carry the mark.

The boiler figures show how much narrower the award is than the testing. Only 30% of boilers tested by Quiet Mark received accreditation, with the noise range assessed along kW output³. That matters because boiler noise is not a single number: a range is assessed across its output sizes, so a small combi and a large system boiler in the same family are not judged as one object.

Scale puts the selectivity in context. Quiet Mark assesses the declared sound measurements of approximately 400 boilers every year and the declared decibel levels of approximately 375 heat pump models each year¹. Against those volumes, the certified list is short. Quiet Mark also reports that its scheme as a whole covers over 1,000 appliances and acoustic materials, from more than 90 global brands, across more than 70 product categories¹.

For a household, selectivity cuts both ways. A badge is meaningful evidence that a specific listed model was judged among the quieter options in its class. It is not evidence that the brand is quiet across its range, and it says nothing about installation quality, siting or the acoustic effect of where the unit is placed.

How products are assessed

Assessment starts before the badge. All boilers and heat pumps are acoustically tested prior to coming to market, carried out to specific ISO standards, within which decibel levels are declared and included on the energy label of each unit¹. Quiet Mark then reviews the declared sound measurements rather than running its own laboratory programme on every unit.

For heat pumps, Quiet Mark states that all heat pumps are tested to the same standards, which gives a decibel level while the product is in operation, with heat pumps split into like-for-like sizes². That size-splitting is what makes a comparison between one unit and another meaningful at all: the units are judged against others of comparable output rather than against the category as a whole.

The wider certification landscape uses a similar principle. Heat Pump KEYMARK covers third-party tests of product performance, sound emission and safety checks, and its stated benefits include certified product quality, compliance with EU standards and Ecodesign, increased consumer confidence and reduced costs for testing, inspection and certification⁵. KEYMARK describes its testing process as strong because it is based on regular measurements of the actual units by neutral bodies, so that consumer expectations for safety and energy efficiency are fully met⁵.

Quiet Mark describes annual re-evaluation of the categories it covers, which is consistent with the yearly assessment volumes it publishes¹. Certification is therefore a judgement on a listed model at a point in time. A badge on a page for a 2023 boiler or a specific heat pump output does not automatically transfer to a revised model, a different output in the same family, or a range that has since been updated.

Boiler brands and models that hold Quiet Mark certification

Vaillant holds the widest set of boiler listings in the material available. Ranges appearing on Quiet Mark include the ecoFIT sustain combi boiler range, the ecoTEC exclusive Green IQ boiler range, the ecoTEC Plus Combi Boiler 2023, the ecoTEC pro boiler range and the ecoTEC plus system boiler range⁷. That spread covers combi and system formats, which matters because a household choosing between a combi and a cylinder-based system is not choosing between certified and uncertified on noise grounds alone.

ATAG appears through the iC Economiser Plus boilers, which Quiet Mark lists as quiet mark certified and notes can be placed in any room of the home¹². That claim is about siting flexibility rather than a sound figure, and it is the kind of statement the badge is used to support.

Two cautions apply to this table. First, a listing is per range or per model, not per brand: Vaillant makes boilers that do not appear here. Second, the badge is a noise judgement only. It says nothing about efficiency, warranty length or support, which are covered separately in the guide to boiler manufacturers and to manufacturer warranties.

Heat pump brands and models that hold Quiet Mark certification

Heat pump listings are more numerous and more granular than the boiler ones, because certification is recorded against specific outputs. NIBE appears with the S1156-8, the S1156-13 and the S735-4, each listed as a tested quiet product or as Quiet Mark Certified¹³. Samsung appears through the EHS Mono HT AE080BXYDEG single phase quiet heat pump, with Quiet Mark certified model numbers listed¹⁶.

Midea's M Thermal Nature Plus Series is listed at two outputs, the MHC-V8WD2RN7-B2 and the MHC-V14WD2N7-B2, both shown as Quiet Mark Certified for the UK market¹⁷. A third Midea entry, the MHC-V12WD2RN7-B2, also appears¹⁹. LG's THERMA V R290 Monobloc is listed at four outputs²⁰. SolaX appears through the Thermal R290 Series STU1-C08R290 outdoor air to water heat pump²⁴, and InstaGen through the IG4-MP1-A1, which Quiet Mark notes allows alerts and notification sounds to be silenced²⁵.

Daikin's certified heat pump listing is the Altherma 3 H HT, with certified models including variations in three phase and single phase, and Daikin also appears as a brand on Quiet Mark²⁶. Vaillant's heat pump side is covered by the aroTHERM plus range, which Quiet Mark records as having received the award, and by the aroTHERM Split air source heat pump, listed as a Quiet Mark certified product²⁸.

Worcester Bosch is a separate case. The manufacturer refers to its Quiet Mark certified heat pumps on its own hybrid systems page³⁰. That is the maker's own statement about its products rather than a Quiet Mark listing, so it carries less weight than a certification page and the specific model should be checked against Quiet Mark directly. For the wider picture on that brand, see Worcester Bosch and heat pump manufacturers.

What Quiet Mark does not tell you

The most important limit is the absence of numbers. Quiet Mark does not publish decibel levels, a line repeated across its product pages and its own guidance¹⁹. The Welsh Government's phase 1 report on air source heat pump noise and permitted development rights records the same position, describing Quiet Mark as assessing the sound quality beyond the dB rating of products but not publishing dB levels⁴.

That leaves a household with a badge and no figure. The declared decibel level for a specific unit sits on its energy label, produced under the ISO-standard acoustic testing every boiler and heat pump undergoes before market¹. Anyone comparing two certified heat pumps, or checking a unit against a planning or permitted development noise condition, needs that declared figure rather than the badge.

Three further limits are worth stating plainly. Certification is a noise judgement and nothing else: it does not speak to efficiency, running cost, warranty or support life. It is a point-in-time judgement, subject to the annual re-evaluation cycle Quiet Mark describes¹. And it is not a substitute for siting: measured sound at the unit is only part of what a neighbour hears, and the Welsh Government work on permitted development exists precisely because installation position and boundary distance drive the outcome⁴.

For a household weighing energy independence, the badge is a small input. A heat pump shifts space heating and hot water off gas and onto electricity, which reduces reliance on a gas supplier but increases reliance on the grid and on the electricity tariff unless the home also generates. Noise certification does not change that balance; it only narrows the field of units likely to be acceptable to the household and its neighbours. The wider trade-offs are set out in heat pump manufacturers and in manufacturers and energy independence.