Samsung EHS Mono HT Quiet heat pump: models and specifications

Samsung's EHS Mono HT Quiet is a high-temperature air-to-water heat pump, sold as a monobloc: one outdoor unit that heats water and sends it indoors through pipework, with no refrigerant pipe running into the house.

The headline specification is temperature. Samsung lists a maximum leaving water temperature of 70°C across the range, and describes that as making the unit "a suitable replacement for gas boilers as provide a high temp"¹. Samsung also states the unit maintains 100% heating capacity at outdoor temperatures as low as -25°C¹.

That combination, high flow temperature and full output in cold weather, is what the HT in the name refers to. It is aimed at the renovation market, where existing radiators and cylinders were sized for a boiler rather than a heat pump³. For a household, the practical question is whether a high-temperature monobloc removes the need to change the rest of the heating system, and what dependence on electricity, an installer and a manufacturer's app it leaves in place.

What the EHS Mono HT Quiet is

The unit is a monobloc air-to-water heat pump. Samsung's own listing gives the type as "Mono" and the mode as "Heat pump (Air to Water)"¹. In a monobloc, the refrigeration circuit is sealed inside the outdoor casing and only water pipework crosses the wall, which is the configuration LG describes on its own monobloc units as "connected by only water piping eliminating the need for refrigerant piping"⁷. That matters for installation because it removes the need for a refrigerant-qualified engineer to work indoors, and it matters for maintenance because the whole circuit stays in one box.

Samsung positions the range for retrofit rather than new build. The 12 kW listing describes it as "a high temperature, low noise heat pump ideal for Europe's residential renovation market"³, and Samsung's own heating pages say the Mono HT Quiet solution "can deliver a high water temperature at low noise levels", making it "ideal for the residential renovation market"⁸. The design is a premium dark colour intended to blend into a building rather than stand out against it¹.

The trade-off in a monobloc is that everything sits outside. There is no separate indoor unit to house, but the outdoor casing carries the compressor, the fan and the controls, so its siting, its clearances and its noise output are all decided at the outdoor position. Where a monobloc can go, and how close to a boundary, is covered in where a heat pump outdoor unit can go, and the difference between this configuration and a split system is set out in monobloc and split heat pumps.

The range: 8, 12 and 14 kW, single or three phase

Three outputs are offered, and each is available on either a single phase or a three phase electrical supply. That gives six model numbers, and all six appear on Quiet Mark's certification listing for the range⁴.

The choice between single and three phase is an electrical question, not a performance one. Both versions of each output carry the same 70°C maximum leaving water temperature and the same 100% heating capacity at -25°C³. Three phase is common in larger properties and in homes that already have a three phase supply; a single phase unit is the usual fit where the house has an ordinary domestic supply. What a property can support, and whether an upgrade is needed, is a matter for the installer's survey, and the wider subject is covered in electricity supply, fuses and wiring for a heat pump.

Sizing is the other decision. The output needed is set by a heat loss calculation rather than by floor area, and the process is explained in heat pump sizing and heat loss calculations. Choosing an output above what the house needs does not make it warmer; it makes it cycle more.

Specifications: 70°C flow and full output at -25°C

The two figures that define this range are the flow temperature and the cold weather output. Samsung lists a maximum leaving water temperature of 70°C, described on the product pages as "Max LWT 70℃: a suitable replacement for gas boilers as provide a high temp"¹. The 70°C figure applies when the outdoor temperature is between -15°C and 43°C³. Separately, Samsung states the unit is "capable of reliably providing 100% heating performance even in extremely cold weather (temperatures as low as -25°C)"¹.

Those two claims do different jobs. The 70°C figure is about what the unit can put into the water, which determines whether existing radiators and a hot water cylinder can be kept. The -25°C figure is about how much heat it can still produce when the air outside is at its coldest, which determines whether the house stays warm on the coldest days of the year without a backup heat source. Samsung's testing is described as internally tested under lab conditions based on EN 14511⁹.

What the specification does not say is how efficiently the unit runs at those extremes. The general relationship is set out in heat pump efficiency: COP, SCOP and SPF, and the case for high-temperature units specifically in high-temperature heat pumps.

For a household, the practical reading is that this range is designed so that a boiler can be swapped for a heat pump without replacing every radiator. That is a real reduction in disruption. It is not a claim that the running cost will match a gas boiler, because that depends on the flow temperature the system actually settles at, the electricity tariff, and how the controls are set.

Noise: Quiet Mark certification and the 35 dB(A) figure

Six model numbers carry Quiet Mark certification: the three single phase units and the three three phase units⁴. Quiet Mark describes itself as "an internationally recognized certification awarded to products that meet rigorous standards for noise reduction"¹⁰, and the certification is held by a wide range of heat pumps, including units from LG, NIBE, Midea, SolaX and ATAG⁷.

The decibel figure Samsung quotes is 35 dB(A), described as "as low as"¹⁶. How that number is arrived at matters more than the number itself. The measurement is taken 3 metres from the front of the outdoor unit, in an anechoic room, with an outside temperature of 7°C¹. An anechoic room has no reflective surfaces, so nothing bounces back towards the microphone, and a 3 metre distance in a straight line from the front is not the same as the distance to a neighbour's window around a corner or over a fence.

Planning rules use a different test in a different place. For air source heat pumps under permitted development rights, the MCS 020 assessment "checks whether the heat pump sound is within a 37dB threshold one meter from the neighbour's window"¹⁷. A laboratory figure of 35 dB(A) at 3 metres and a boundary figure of 37 dB at 1 metre are not comparable, and passing one does not establish the other. The assessment itself is explained in MCS 020: the heat pump noise assessment, and the wider subject in how noisy is a heat pump.

Quiet Mark does not publish decibel levels for the products it certifies¹⁸, so the badge indicates that a product met the scheme's criteria rather than giving a figure to compare against another unit. For a household, the certification is a starting point; the siting of the unit relative to a neighbour's window is what decides whether the installation is acceptable.

Smart control: SmartThings and energy monitoring

The range is compatible with Samsung's SmartThings app, which the product listings describe as "allowing you to monitor and control your heating system remotely"¹⁶. That is the manufacturer's app route, and it sits alongside the physical controls on the unit and any wired thermostat in the house.

Remote control of a heat pump is not the same as monitoring a home's energy use. Smart meters support whole-home energy monitoring¹⁹, and they come with an in-home display²⁰. Smart heating controls "automatically optimise your heating settings to save you money and energy"²¹. Official guidance notes that smart meters are independent of smart heating controls, but that "combining the two can enhance your ability to manage your home's heating and energy use remotely"²². In Wales, the same point is made in the Welsh Government's guidance on smart meters²².

The distinction matters for independence. A heat pump controlled through a manufacturer's app depends on a home broadband connection, the manufacturer's servers and the app continuing to be supported. A smart meter and its in-home display depend on the energy supplier and the national smart meter network. Neither is a substitute for the other, and neither removes the need for a working local control on the unit itself. The wider subject is covered in heat pump controls, weather compensation and smart operation.

Installation and maintenance: side panel access

Samsung describes the unit as "simple to set up and maintain with easy side panel access"¹. In practice that means the panels an engineer needs to remove for servicing are reached from the side of the casing rather than requiring the unit to be moved or the front to be cleared. For a monobloc, where all the working parts are in one outdoor box, that access is the difference between a routine service and a dismantling job.

The control kit is the interface between the outdoor unit and the rest of the system. There is no published UK price for the MIM-E03EN control kit in the material available here, so it is installer-quoted and normally appears as a line in a full installation quote rather than as a separate retail price. The same is true of the pipework, the cylinder and the labour.

Servicing arrangements for heat pumps generally, including what a service covers and how it interacts with a warranty, are set out in heat pump servicing and maintenance and does servicing a heat pump affect the warranty. The installation process from survey to handover is covered in heat pump installation.

What it costs in the UK and where to buy

Samsung lists the range on its UK Climate Solutions site, and Quiet Mark lists the models as certified products available for the UK market¹. Samsung also notes that "these products may only be available in specific regions"², so availability of a particular output should be checked locally rather than assumed.

On price, the figures that exist are retail listings for Samsung monobloc units rather than for this range specifically, and they vary widely between listings. An 8.0 kW Samsung monobloc is listed at £2,618.99 and a 16.0 kW unit at £3,490.15²³. A separate listing shows an 8.0 kW high temperature quiet monobloc at £4,614.99, with a stated high street price of £5,949.99, and an 8.0 kW monobloc at £2,618.99¹⁶. These listings disagree with each other, and the documents do not resolve the difference, so they should be read as indicative rather than as a price for a particular model.

What moves a quote is the same as for any heat pump: the output and phase of the unit, whether a cylinder is being replaced, whether radiators need changing, and the electrical and flue work. Wider cost context is in how much does a heat pump cost in the UK, and grant support in heat pump grants and funding across the UK.

Refrigerant and the 2027 rule change

The EHS range is listed as using R410A in government guidance on domestic hybrid heat pumps⁵. That is a high global warming potential refrigerant, and it puts the range on the wrong side of a rule that takes effect shortly.

From 1 January 2027, only refrigerants with a global warming potential below 150 may be placed on the market for all split systems up to 12 kW and self-contained monobloc systems up to 50 kW²⁴. R410A is well above that threshold. The rule governs what can be placed on the market from that date rather than what can continue to be used, but it is a material consideration for anyone buying a monobloc now and expecting to keep it for its working life.

The alternatives and the regulatory background are set out in heat pump refrigerants: R290, R32 and the F-gas rules and R290 vs R32 heat pumps. Samsung's own R290 monobloc range is covered in Samsung EHS Mono R290 heat pump.

What a high-temperature monobloc means for energy independence

A heat pump changes what a home depends on. It removes the gas connection, the gas supplier and the standing charge that goes with them, and replaces them with electricity. That is a real shift in sovereignty: the fuel is no longer piped in from a network the household cannot choose to leave, and a home with solar panels and a battery can generate and store some of its own heat. The wider picture is in heat pumps and household energy independence.

What remains is a set of dependencies. The home still draws from the grid, still buys from an electricity supplier, and still relies on the unit's manufacturer for parts, controls and any app-based features. A monobloc adds one more: because the refrigeration circuit is sealed in the outdoor casing, servicing and repair of that circuit stay with a qualified engineer and, in practice, with the manufacturer's parts supply. The 70°C capability reduces one dependence, the need to replace radiators and a cylinder, but it does not reduce the electrical one.

The honest position is that this range is designed to make a heat pump fit an existing heating system with less disruption than a low-temperature unit would. It does not make the home independent of the grid, and it does not remove the need for a properly sized system, a competent installer and a tariff that suits how the unit runs. What it does is widen the set of homes where a heat pump is a practical swap rather than a whole-house project.