Combi Boiler, Condensing Boiler or Heat Pump?

A heating decision is one a home — or a building — will live with for at least ten years. Pick the wrong appliance and it shows up every winter on the bill and at every service visit. To pick the right one you need to know all three candidates properly: the combi boiler, the condensing boiler and the heat pump. We install all three regularly, and we know from site work where each of them wins.

The combi boiler: the standard for an apartment

A gas combi boiler is the default answer at apartment scale in Türkiye, and not without reason: the first cost is reasonable, installation is quick and service is available everywhere. If you are buying today, choose a condensing model without hesitation — because it recovers the heat in the flue gas, it saves a meaningful amount of fuel compared with a conventional unit. The thing to watch is capacity: a boiler chosen oversized “just to be safe” short-cycles and runs inefficiently.

The condensing boiler: the answer at building scale

Once you are talking about a block, a residential complex or a commercial building rather than a single flat, the nature of the job changes. A central boiler system heats from one point at high efficiency instead of dozens of independent combis; maintenance happens in one place and the flue problem is solved in one place. With a cascade arrangement the capacity is staged to match demand: at low load one boiler runs, at peak they all come in. Evening out the comfort differences between flats then comes down to heat cost allocators and hydronic balancing.

The heat pump: the running-cost champion

A heat pump runs on electricity but it is not an electric heater; it moves heat in from the outside air. Producing 3-4 kW of heat for every 1 kW of electricity it consumes (a COP of 3-4) puts its running cost level with natural gas and, in most scenarios, ahead of it. On top of that it cools in summer. It gives its best results with low-temperature systems such as underfloor heating. In areas with no gas infrastructure it has no real competition. We have collected the installation details for Ankara on our heat pump page.

Side by side

A practical decision guide

• Living in a flat with gas available: a condensing combi is the safe choice.
• Managing a building or complex: a central condensing boiler plus hydronic balancing.
• Building a new villa or detached house: think seriously about a heat pump with underfloor heating; over the long run this is the cheapest to operate.
• No gas infrastructure: the heat pump is effectively the only sensible candidate.

Whatever the point you are stuck on, we would rather come out for a survey and talk in firm numbers based on the building’s heat load — not “in our opinion”, but “according to the calculation”.

Projenza Engineering and Energy Solutions — an Ankara-based mechanical installation and energy company. About Us • Services • Projects • References