Saunier Duval 5Bar Isomax Boiler Pressure Collector

✅ BOILER INSTALLATION FLUE OUTLET 1.

✅ Flue outlets for each type of boiler The first thing you need to be clear about is the type of gas boiler you are going to install: a room-sealed low nitrogen oxide (NOx) emission boiler or a condensing boiler.

✅ Each boiler model requires a different flue outlet, both in the type of material and in the slope it must have.

✅ Room-sealed boiler It always has a metal flue outlet, normally aluminium, either painted white or unpainted.

✅ As it is a sealed-chamber boiler it needs two pipes: one that draws clean air from outside and carries it to the boiler, and another that expels to the outside the fumes the boiler produces when burning.

✅ The flue outlet for room-sealed, low nitrogen oxide (NOx) emission gas boilers can be coaxial (vertical or horizontal outlet) or twin-flow: Coaxial installation: consists of one pipe inside another, normally 60 mm in diameter for the inner pipe and 100 mm in diameter for the outer one.

✅ The inner pipe is responsible for expelling the gases, while the space between one pipe and the other supplies clean air to the boiler.

✅ The most important thing with this type of flue outlet is the total distance: in the best case, it is usually no more than 6 m in total, although there are boiler models that do not go beyond 4 m.

✅ Within the coaxial outlet there can be two possible types of installation: Coaxial vertical outlet installation: this type of flue outlet is characterised by leaving the boiler in a vertical position.

✅ Its installation is suitable for flats and houses where the boiler is right below where the chimney arrives and can be connected directly.

✅ Whenever this installation is used, it is advisable to fit an accessory called a "condensate collector" so that, in case of rain or if there is some condensation in the chimney, it prevents water from entering the boiler.

✅ To prevent dirt, trim covers can be fitted to the top of the pipe, which block the entry of dirt, birds and rain.

✅ It is highly recommended to fit trim covers in the installation.

✅ Coaxial horizontal outlet installation: as in the previous model, this type of flue outlet has two pipes, one inside the other, and the maximum distance it can reach with a room-sealed gas boiler is about 6 m (always check the boiler's specifications).

✅ It differs from the previous one in that it leaves the boiler sideways and is installed whenever the chimney has to be led outside through the wall.

✅ If you are going to fit this type of flue outlet, remember that it needs to slope outwards to prevent water produced by condensation or rain from entering the pipe.

✅ Example of boiler installation with coaxial outlet: Twin-flow installation: consists of two separate pipes and has the advantage of allowing the boiler a maximum installation distance of 20 m for gas discharge and 20 m for clean air intake from outside.

✅ It is normally installed in newly built flats, where the boiler on the first floor must, by regulation, vent the fumes at the highest part of the building.

✅ The two-pipe flue outlet has different dimensions from the coaxial ones.

✅ It usually has two pipes of 80 mm diameter each and, like the previous ones, is made of aluminium (painted or not).

✅ Example of installation for flue outlets with separate pipes: Condensing boiler It differs from the previous one in that the fumes leave at a lower temperature, which is why they condense and cause a flow of water to return towards the boiler.

✅ This boiler comes prepared for this water flow and it is not necessary to install a condensate collector as with traditional boilers.

✅ Bear in mind that to install a condensing boiler a drain connection is needed near the boiler so that it can constantly discharge water.

✅ There are three possible types of flue outlets for condensing gas boilers: Coaxial vertical flue outlet: As we have already seen, the vertical flue outlet is characterised by leaving the boiler directly upwards.

✅ However, with the condensing boiler it is not necessary to install a condensate collector since it is designed to take in water.

✅ Another of the main differences is that the pipe material is polypropylene.

✅ As it does not expel gases as hot as other boilers, it does not need metal pipes but rather a plastic capable of withstanding the corrosive water created by condensation.

✅ The usual dimensions of the flue outlet of a condensing boiler are 60 mm inside diameter and 100 mm outside diameter.

✅ Coaxial horizontal flue outlet: It also consists of two pipes, one inside the other, but in this case the slope must point towards the boiler so that it can collect the condensation water and drain it through the built-in drain.

✅ The pipes are made of polypropylene.

✅ Twin-pipe flue outlet: Consists of two 80 mm polypropylene pipes that allow the boiler to expel gases over a much greater distance than with a coaxial flue outlet.

✅ The gas exhaust pipe must always slope towards the boiler so that it collects the condensation water.

✅ Some gas boiler manufacturers make somewhat larger coaxial outlets so that they can reach more metres: this pipe size is 80 mm inside and 110 mm outside and they reach up to about 8 m maximum. 2.

✅ Installing the flue outlet Before choosing a boiler you need to know how the flue outlet is going to be installed and ask for the boiler model that best suits your needs.

✅ Once the flue outlet has been decided, the next step is to confirm the existing hydraulic and gas connections in the home.

✅ Each manufacturer has a particular configuration of the inlet/outlet connections, so you need to see which brand best suits the conditions you have at home.

✅ You need to find where the connections are located.

✅ One of the most common layouts is the one we show you below: All gas boilers include a diagram similar to the example so that you can see whether it fits the position of the water inlets and outlets in your home.

✅ If you cannot find a suitable model, the connections will have to be modified with copper pipe so that they fit the boiler's perfectly.

✅ Remember that the order of these connections must always be respected or the gas boiler will not work properly.

✅ Example of a hydraulic and operating diagram of a gas boiler: 3.

✅ Boiler connections Each boiler connection has a different function: Domestic hot water outlet: takes the already heated domestic water to the taps throughout the home.

✅ Cold water inlet: this is the connection where the mains water is connected directly.

✅ Heating return: this is where the return pipe from the radiators must be connected, that is, where the water from the radiators returns to the boiler to be heated again and continue circulating through the heating circuit.

✅ Heating outlet: the pipe carrying the already heated water to the radiators is connected here.

✅ Gas inlet: the gas must be connected here.

✅ It is very dangerous and must never be carried out without the supervision of a professional.