David Hall, UK Director of Firebird, explores how the redesign of the company’s Envirogreen oil-fired combi boiler is making life easier for installers.
The combi boiler is undoubtedly the most popular type of boiler in the UK and in off-grid areas an oil-fired version is usually the first choice for smaller households with limited space. Although simple to install, from it is equally important to have a boiler that is easy to service and maintain. This type of boiler was long overdue for a re-design and we believe the Firebird Envirogreen combi HE range has quite literally revolutionised current boiler design thinking, making life a whole lot easier for the installer.
So, what has changed?
Accessible pipework connections, front service access, multi-directional flue options and a long, comprehensive warranty are all important considerations when choosing a boiler. But where the Envirogreen Combi really comes into its own is the Firebird by elco Low NOx burner. At 60mg/kWh it not only has lower emissions than any other boiler on the market, but is easily installed, commissioned and serviced using a single Allen Key. The trouble-free ‘plug and play’ burner, which requires only two settings for pump and air pressure, makes installation a breeze. To ensure the highest level of efficiency is achieved by the burner, the CO2 level is factory-set at optimum 12.5%.
Should this need to be adjusted for any reason, the CO2 level settings are printed on the burner casing, acting as a handy reference guide. With a Firebird digital control box and a simple diagnostic system, installation really couldn’t be more straightforward.
When selecting a boiler, long-life serviceable components are also something that should be taken into account. The electro-mechanical flow switch, for instance, which activates the hot water function, has been replaced with a temperature sensitive thermistor. When a hot water tap is opened, the thermistor will sense a change in conditions and electronically activate the boiler control circuits to run the circulating pump, which diverts the store water through the compact plate heat exchanger.
Another major development is the design and introduction of a ‘Hydroblock’, which reduces the number of individual components by incorporating them into a single moulded brass block. This improves fault diagnostics in the field and cuts unnecessary downtime due to leaks that may occur when the boiler is operating under pressure. The reduction in the number of pipework connections makes installation simpler and lowers the amount of maintenance required.
As oil-fired combi boilers have to perform two functions (heating and DHW), the width of a standard boiler has predominantly been in excess of 600mm. To overcome this, instead of the twin circulating pump approach used in most oil-fired combi boilers to perform these functions, Firebird has utilised a single, ‘A’ rated Grundfos pump and electronic diverter valve which uses integrated pressure-control to meet these requirements. This not only means that the size of the Envirogreen Combi HE has been reduced to 595mm in width, but equally as important, it has created a great space to work inside the boiler.
Corrosive debris that may be present in the primary pipework can potentially cause premature failure of the primary heat exchanger through pitting corrosion. Best practice flushing and inhibitor dosing reduces this risk, but the flow through the heat exchanger is also a key factor. In line with standard European practice, a complete unit has been designed which houses the secondary heat exchanger beneath the primary heat exchanger. By locating this unit at the bottom of the appliance, a wet top/bottom that promotes consistent flow through the boiler jacket is created. This type of design helps to eliminate corrosion failure and boiler inefficiency, as the potential for corrosive debris product build-up in the jacket flow paths and cavities is significantly reduced.
In off-grid areas of the UK there is still no real financially viable alternative to oil at current, so any advances in boiler technology that make installation, servicing and maintenance trouble-free will be welcomed with open arms.
Future in oil?
While oil may not offer the perfect solution in terms of carbon emissions, Firebird believes a modern high-efficiency oil system such as the Firebird Envirogreen range can provide an environmentally acceptable alternative to renewable alternatives.
Oil, it would seem is here to stay; whether in its current form, or as a reduced carbon liquid in the not too distant future.