Combi Boilers for Apartments and Flat
Combi Boilers for Apartments and Flat

Combi Boilers for Apartments and Flat

Combi Boilers for Apartments and Flat

A combi boiler is ideal for a small house or flat with one bathroom and roughly ten radiators. They're energy-efficient, provide hot water on demand, and take up little space. Because there are so many advantages to installing a combi boiler, each manufacturer offers its selection. It might be challenging to know where to begin because of this.


A combi boiler is the best heating option for tiny houses and flats. Combi, system, and conventional boilers are the three types of boilers. Only combi boilers do not require any external components (tanks in the loft or a hot water cylinder). As a result, they're small heating systems, and the only area you'll need to dedicate is a spare kitchen cabinet.


They are both compact and draw hot water directly from the mains. This means they can respond quickly if you want heating or hot water. The sole disadvantage is that, unlike regular and system boilers, they cannot fulfill significant heating demands since they do not store domestic hot water in a cylinder. As a result, they're ideal for tiny houses and flats with only one bathroom.

Why Choose Combi as a Boiler

A combi boiler is a gas boiler that combines a water heating system and a central heating unit into a single body to provide immediate hot water, minimising the need for a separate hot water tank.


One benefit of integrating two distinct boilers into one body is that it takes up substantially less area in your house than a system or ordinary boilers, making them excellent for homes where space and storage are a concern.


If you intend to purchase a combi boiler, use the table below to find out what size boiler you’ll need for your flat. Generally, flats have fewer bedrooms, bathrooms, and radiators, so you’ll likely require a boiler with an output of between 24kW and 28kW.


Result in kW







Up to 10




Up to 15




Up to 20

Consider Equipment Life

It would help if you also remembered that one massive water heater would fire at a lot greater BTU, which means it would burn substantially hotter than it would in a modular setup. Even if the single commercial boiler is designed with more lasting components, the increased heat will cause more wear and tear, affecting the equipment's entire life.

In contrast, the reduced heat on the smaller modular units will allow these boilers to survive longer and have longer equipment life.

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Q: What kind of fuel does your boiler use?

Piping Considerings

Anytime a single, big commercial boiler is put in your apartment building, it will be responsible for all the hot water for the property. However, numerous smaller units in a redundant or staged boiler system can share the strain.


With the more efficient staged approach, each smaller boiler fires up to fulfill the demand of your renters – as needed. Your staged system can be piped in one of two main ways: flat system piping or piped in a series. Let's look at how these plumbing options function with three tiny boilers sequenced in a row: Boiler A, Boiler B, and Boiler C.

The Better and Balanced Solution

Boilers X, Y, and Z are piped parallel with a balanced system. This implies that all three units will operate simultaneously but run at a substantially reduced pace. The three units will supply their demands evenly whenever residents require hot water.

Multiple water heaters e sequenced or balanced and are ideal for multi-family boilers for flats.


When the units are piped in parallel, they're piped in a single line and given hot water one at a time. It can run erratically to meet hot water demands. In a series piping:



Boiler X always operates very hard in this configuration. Therefore, it will break down quicker than Boiler Y or Boiler Z.

One Large Boiler vs. One Boiler System

Although one industrial boiler may seem like the cheaper alternative, what happens when it breaks down? When the one commercial boiler is down, the whole unit is down; and residents are out of hot water. Similar to a light bulb, the boiler system is either on or off – no in-between alternative exists.


In contrast, when you pick numerous smaller modular boilers for apartments — such as multifamily condensing boilers — the other boilers will continue running and piped to keep the property with hot water. While you may have less hot water if one boiler goes down, employing numerous boilers for your home will have a less negative impact than a single industrial boiler.

Contact Us For Special Offers

Choosing the correct boiler system for apartment complexes can be difficult and daunting. However, you don't have to do it alone. The specialists at Zara Heating have been aiding contractors, end-users, property & facility managers, and engineers.