Baxi
The Baxi HP60-8-1-PHMB is an 8.5 kilowatt monobloc heat pump using R290 refrigerant. It delivers flow temperatures up to 75 degrees Celsius with an A triple-plus efficiency rating.
The Baxi HP60-8-1-PHMB and Assure HP55-8-1-PHMB are 8.5 kW monobloc air-source heat pumps designed for domestic heating and hot water. Utilizing R290 refrigerant with a low GWP of 3, these units provide high-temperature performance up to 75°C. They achieve an A+++ ErP rating with a SCOP of 5.2 at 35°C. This technical guide provides essential data for heating engineers regarding installation clearances, electrical requirements, and hydraulic specifications for these single-phase units.
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Full technical specifications extracted from the manufacturer brochure. Empty sections are hidden.
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The Baxi HP60-8-1-PHMB and Assure HP55-8-1-PHMB represent a high-performance monobloc solution for UK residential retrofits and new builds. Both models deliver a nominal capacity of 8.5 kW at A7/W35 conditions, maintaining operational capability down to outdoor temperatures as low as -25°C. A significant technical advantage is the maximum flow temperature of 75°C, which allows for effective legionella cycles and potential compatibility with existing radiator circuits without extensive resizing.
Efficiency is a core metric for these units, evidenced by the A+++ ErP rating at both 35°C and 55°C flow temperatures. The Seasonal Coefficient of Performance (SCOP) reaches 5.2 at 35°C and remains high at 3.89 for 55°C applications. This performance is underpinned by the use of R290 (propane) refrigerant. With a Global Warming Potential (GWP) of just 3 and a charge of 1.1 kg, R290 is a future-proof choice that meets tightening environmental regulations while providing superior thermodynamic properties compared to traditional synthetic refrigerants.
From an installation perspective, the monobloc design simplifies the process by containing the entire refrigerant circuit within the outdoor unit. The physical footprint is substantial, with a width of 1390 mm, a height of 872 mm, and a depth of 523 mm. Engineers must account for the 122 kg unit weight during siting. Minimum clearances are strictly defined to ensure adequate airflow and service access: 300 mm behind the unit, 500 mm at the sides, and 1000 mm at the front. The unit operates at a sound power level of 49 dB(A), which translates to a sound pressure of 41 dB(A) at one meter, facilitating compliance with MCS-020 noise assessments in typical suburban environments.
Electrical requirements specify a 230V single-phase supply with a recommended 20A MCB. The hydraulic circuit is rated for a maximum operating pressure of 3 bar. For hot water provision, these heat pumps are compatible with Baxi ASHP Pre-plumbed Cylinders or standard ASHP-specific cylinders. Control is managed via the Baxi START App, providing end-users with remote access while allowing engineers to monitor system performance. The manufacturer offers an extended 7-year warranty, subject to terms and conditions, providing long-term assurance for both the installer and the homeowner.
Common questions from engineers and homeowners about the Baxi Assure HP55-8-1-PHMB.
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Specifications on this page are extracted from the manufacturer brochure. Always cross-check against the latest datasheet before commissioning or quoting. Last updated 30 April 2026.