They are designed to heat water instantly for domestic use. A combi boiler heats water from the cold mains directly and as you turn on the tap, the water is heating before it reaches the tap outlet. Once you finish taking a shower, or finishing the dishes you just turn the tap off, signaling the boiler via the flow switch and the boiler stops heating the water. They have a second heating unit, which gives you instant hot water. Are you wondering how a combi boiler works?
The boilers do not have any type of storage tank. They are also able to give heat to the central heating system. The thermostat will tell the boiler when the heating system will need to come on. Then, the pump that is inside of the boiler will fire up. There is a small game in the pipe that the water will start to flow through. This is known as the venture effect. This will create a pressured differential, which is going to cause the gas valve to open up.
From here, the gas is going to be ignited into the main burner. The heat exchange holds a limited amount of water, which is rapidly heated up when you turn on the tap. It circulates around the boiler through the heat exchange. If the water expands, it is absorbed by the sealed expansion vessel.
The thermostatic element is going to be expanding when the temperature has arrived at sixty degrees Celsius. When this happens, the hot water valve is going to close up and the heating valve is going to open. This is going to allow the water to flow to the main heating system.
What does it mean when a boiler is condensing like most of them do? This means that they are cooling the flue gases down in order to produce energy. This is going to lower the cost to run it and improve the efficiency. The process will cause a build up of acidic condensation that will consist of a PH balance between three and four. The condensation will be leaving through a pipe and is going to leave out the drain. It is important that you place the boiler near a drain for this very reason.
The boiler is not going to turn on unless the fan is on. It is important that you check the pipe and make sure you have the right one. You wouldn’t want the acidic condensation to eat through the pipe. Make sure it drains properly as well.
Combi boilers are more suited to small apartments or single-family houses. One of the gases produced by the Combi-boiler is steam (vapor water). A typical increase of efficiency is ten to twelve percent.
If your looking to have a new Boiler installed including the efficient Combi boiler check out Northern Gas Heating who won the Domestic Installer of the Year award at H&V News Awards 2010.