Comfort Optimum

    • Reduce your energy consumption by up to 75%
    • Year-round comfort with built-in cooling function
    • Optimum technology for higher annual efficiency
    • Efficient hot water production with TWS technology
    • Flexibility – for new-builds or refurbishments
    • One solution – heating, domestic hot water and cooling
    • Low sound level
    • Online – control your heat pump from anywhere
Thermia Comfort Optimum

energy class when the heat pump is part of an integrated system


energy class when the heat pump is the sole heat generator Energy class according to Eco-design Directive 811/2013



  • Efficient performance in all seasons

    Efficient performance in all seasons

    The Thermia Comfort Optimum is a ground-source heat pump that offers you high annual efficiency thanks to its unique technical solutions. With an impressive coefficient of performance (COP) of 4.34 (Diplomat Comfort 10 at B0/W35 according to EN14511), the Thermia Diplomat Optimum Comfort enables you to reduce energy consumption by up to 75%.

  • Heating


    Most common European heating systems are water-based, with heat being distributed via radiators or hydronic floor heating. The output temperature of the water distribution system is usually 30-35°C for floor heating and 45-55°C for radiators. Thermia heat pumps offer a low-carbon alternative to traditional boilers in modern buildings, whether for new-builds or refurbishments and regardless of the temperature required in the heating system.

  • Cool in the summer

    Cool in the summer

    The heat pump provides heat during the winter while in the summer the process can be simply reversed. The heat pump collects heat from the house and deposits it into the ground borehole to provide cooling. The Comfort Optimum provides cooling as a result of the passive cooling module built into the unit. By circulating the cool brine in the ground loop, cooling is produced at a very low cost, which is significantly more cost-efficient than traditional air conditioning.

  • More hot water, faster

    More hot water, faster

    The hot water tank is fitted with our TWS (Tap Water Stratification) technology, which means that hot water is produced faster and at higher temperatures than with traditional technology. Because the hot water is diluted to tap water temperature, the volume of usable hot water is considerably higher due to the high temperature.

    Thermia versus other brands in terms of hot water production:

    Thermia with TWS technology Typical traditional water heater
    • Recharging from 40°C to full load for a water heater using TWS technology: just 21 mins.
    •  Recharging from 40°C to full load for traditional water heater: 50 mins.
    • Time to fully recharge tank after peak consumption: 21 mins.
    •  Time to fully recharge tank after peak consumption: 50 min.
  • Intelligent control system

    Intelligent control system

    The controller coordinates and controls the heating system. Thermia heat pumps work with complete precision to give your home the best possible indoor climate at the lowest possible cost. Our controller is very easy to use.

    The controller displays visualized heat curves and, once it is set, you never need to think about it again. Raising or lowering the temperature can be achieved at the touch of a button.

  • Optimum technology

    Optimum technology

    Optimum Technology is a technology that constantly monitors your system and adjusts the pump’s performance accordingly. The controller continuously monitors the system and, if needed, automatically adjusts the speed of the circulation pumps to maintain the defined temperature delta for brine and heating circuit. Speed-controlled Class-A circulation pumps guarantee that daily operation is always adjusted according to the user’s requirements and conditions. This means that you can be sure your heat pump is always running at its most efficient level.

  • Flexibility


    Thermia Comfort Optimum is available in four output sizes: 4kW, 6kW, 8kW, 10kW, in a three-phase (400V) version only. Diplomat Optimum Comfort has built-in 180-liter hot water tank. With a range of accessories, it can also be adapted to heat a swimming pool.

  • Thermia Online

    Thermia Online

    The Thermia Online app enables you to check that your heating system is working properly, reduce the temperature when you are on holiday, or receive a notification if anything unexpected comes up. Our online system provides installers with comprehensive diagnostics data and also enables them to respond promptly to notifications or access a live feed on system performance. The Thermia Online app is available for both Android and iPhone.

  • Pool heating

    Pool heating

    Thermia Comfort Optimum can easily be supplemented to heat your pool, all year round. In this way, you can enjoy your pool in all seasons while substantially reducing the cost of heating it.

  • The essence of Scandinavian design and durability

    The essence of Scandinavian design and durability

    Thermia heat pumps are designed, tested and manufactured in one of the harshest climates in Europe. Swedish winters can be extreme. February is usually the coldest month, with temperatures dropping as low as -30°C or even lower in the north and heating is essential from September to May. Thermia Diplomat Optimum Comfort is built on 40 years’ experience of developing and supplying heat pumps.

Climate protection begins at home

Climate protection begins at home

Air and ground source heat pumps have the potential to reduce your home’s CO2 emissions by up to 50% and can act as your individual contribution to the commitment to source 20% of European energy from renewable sources by 2020.


If you have any questions please contact us

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Heat Pumps Ireland

0845 299 72 72 1890-948200 042-933 86 88

Ashgrove Renewables

Tel: +353 (0)22 47900