The basic functionality of a conventional boiler is to get as much out of the heat it burns as possible. Although typically in relation to gasses given off it doesn’t perform to the standard of a combi boiler it will however retain heat from this lost gas and further use it heat hot water in as economical manner as possible. This conversely means that it won’t need as much heat from the burner. when increasing water temperature.
An interesting fact regarding modern boilers is due current building regulations all new domestic boilers should have the capacity to be either condensing or non condensing. What this means is that a combination boiler in order to meet these regulations will take in air from inside the room where as the conventional boiler will operate as normal and take air in from outside.
Due to the nature of the structure of a condensing boiler it does require more ancillary components such as circulation pump, cylinder or water tank and also an expansion tank in the loft. Hot water will be stored in a tank and is switched on when you know you are going to need ir conversely can be operated on a timing based system.
Condensing Boiler Positives
– They are good for large scale heat production
– Over time they are at least 25% more efficient than non condensing models
– The system utilises a very large percentage of the heat it produces
Condensing Boiler Downsides
Once the storage tank runs out of hot water you will have to wait for the water to reheat, thus there is the constant concern of running out of hot water.
Opting for a heat only gas boiler systems
If you think you’ll need a heat only boiler, but don’t want lots of external components, a sealed system could be more suitable. This is a boiler system with a hot water cylinder, but the feed and expansion tank (usually in the loft) is replaced by an expansion vessel in the boiler, which also typically contains the circulation pump and may house some of the valves.
A heat only boiler could be the solution for you, this sealed system does exactly what it says. The loft expansion tank is replaced by an expansion vessel the boiler itself will also consist of the circulation pump.