In standard boilers up to 20% of the energy produced is lost to the atmosphere through the flue system. Condensing boilers are designed to capture part of this lost energy (latent heat) and can therefore maintain extremely high efficiency levels. See our article ‘What are Condensing Oil Boilers?’ for more details.
No, condensing oil boilers can only run on kerosene. All Grant condensing boilers are also HVO biofuel compatible and so can future-proof your home for its changing heating needs.
The Award Winning Vortex boiler was launched in 2001, in the subsequent years that followed there was a customer demand for a competitively priced ‘A’ rated boiler, the design team at Grant devised the Euroflame range to meet this growing consumer demand.
Both the Vortex and Euroflame are high efficiency boilers, the major difference being the efficiency, the Vortex efficiency is from 92.6% to 97%, whereas the Euroflame efficiency is 92.1% to 93% and both are ‘A’ rated boilers, there would be a difference in price with the Vortex being slightly more expensive.
The Vortex has a larger heat exchanger area which gives it a higher efficiency than the Euroflame, the Vortex module has a frost stat and a service switch inbuilt.
There are 28 model variants in the Vortex range and 9 model variants in the Euroflame range, there is a Grant boiler suitable for every domestic application.
Features and characteristics of both Vortex and Euroflame are:
The award winning Vortex stainless steel heat exchanger and turbulator baffle system for ultra high efficiency
All models are Harp Band ‘A’ rating
Factory fitted internal condensate traps to make sitting the appliance straight forward
The unique heat exchanger is covered by a 5-year guarantee.
All Vortex and Euroflame boilers are compatible with Grant’s EZ-fit flue systems, which include low-level, high-level, rigid and flexi vertical balanced kits and also flexible and external conventional flue packs.
Seasonal Efficiency is the average annual efficiency achieved in typical domestic situations, and is confirmed by independent testing bodies.
These figures are verified on www.seai.ie. A simplified explanation of Seasonal Efficiency is that this is the average efficiency of the boiler over a year, taking into account climate, housing conditions, occupancy patterns, and controls.
Combustion Efficiency is defined as the amount of heat released during combustion over the heating value of the fuel burned.
This is usually shown as the net efficiency on a digital flue gas analyser, and may be higher or lower than the Seasonal Efficiency, depending on the time of year and the heat load.
We recommend that Outdoor Boilers should have a Frost Stat fitted. The Grant Vortex Module range is factory fitted with a Frost Stat set at 1.5ºC plus or minus 1ºC. A permanent live is required with a frost stat.
For added frost protection on Grant Vortex Modules, fit a pipe thermostat on a return pipe, set at 30ºC and wired to number 5 & 6 on the control panel. This will prevent the boiler heating the house unnecessarily. A bypass must also be fitted when wired as above.
Frost stats come as standard on all Grant Vortex Outdoor Modules. They are set at 2°C plus/minus 1°C and require a permanent live to the boiler.
Yes there are a number of products which may be used to give frost protection to domestic central heating systems. For total system protection against freezing particularly during extended periods without electrical power, we recommend the use of a combined heating system antifreeze and corrosion inhibitor used in accordance with the manufacturer’s instructions.
It is advisable to let your condensate run into a soil stack or the larger the diameter of pipe the better as this will help to prevent freezing water. If your condensate trap is not run off into a soil stack pipe and its running into a smaller waste pipe then remove the bung on the condensate trap.
In almost all applications you will not be able to use the existing flue. With condensing boilers there is a lower flue gas temp which leads to condensation/moisture in the chimney/flue. The condensing boiler will need a Grant approved flue which is stainless steel and properly sealed at the joints to prevent leakage.
As flue gas temperatures are very low on condensing boilers, a plume of water vapour can often be seen at the terminal (similar to your breath on a cold day). This is the boilers normal operating mode, but if this is likely to cause a nuisance to yourself or a neighbour’s property, we recommend you install a high level, vertical or a plume kit flue.
A condensing boiler has a second (condensing) heat exchanger where the flue gases are cooled to below their dew point by the water returning from the heating system. This has the effect of condensing the water vapour present in the flue gases, and liberating the heat energy that would otherwise be lost to outside through the flue system.
A combi (combination) boiler produces both heating and hot water from one compact appliance. No additional hot water cylinder is required, and the hot water produced by combi's is sent to your taps at mains pressure, which makes combi's an attractive proposition, especially when space is at a premium within the home. You save both money and time on the installation of a combi too, as there is less additional components to install.
Yes. The boilers are exactly the same as those fitted indoors, but are fitted inside a highly insulated weatherproof casing instead.
You should have your oil burner serviced annually by a competent oil service technician.
The serial number is a 15 digit number , located on a data plate on the inside panel of your boiler.
Grant oil condensing boilers need to be connected to a flue to remove the combustion gasses. Even if you are replacing your Grant boiler with a new version, you will require a new flue system too. It is not possible to connect to the old existing flue or liner, due to build up of debris, which could fall back into your new boiler and affect its performance.
Grant EZ-Fit Flue options
Grant has a range of unique EZ-Fit Flues. These are available as low level, high level or vertical kits, for internal and external applications, and even as unique EZ-Flexi liner packs, designed to enable condensing boilers to utilise an existing chimney. It is also possible to convert existing low-level flues to high level after installation.
Apart from the benefits of so many options the Grant EZ-Fit flue systems ensure ‘pluming’ is kept well out of the way of any windows, air vent or doors and out of sight.
Flue Terminals
The flue terminal (end part of flue situated externally) should be positioned so as to avoid combustion gasses accumulating in stagnant pockets around, or entering inside the property. Care should also be taken that the plume from a condensing flue does not cause a nuisance.
See our article on clearance for balanced flues for clearance distances in accordance with Building Regulations.
As flue gas temperatures are very low on condensing boilers, a plume of water vapour can often be seen at the terminal (similar to your breath on a cold day). This is the boilers normal operating mode, but if this is likely to cause a nuisance to yourself or a neighbour’s property, we recommend you install a high level, vertical or a plume kit flue.
In almost all applications you will not be able to use the existing flue. With condensing boilers there is a lower flue gas temp which leads to condensation/moisture in the chimney/flue. The condensing boiler will need a Grant approved flue which is stainless steel and properly sealed at the joints to prevent leakage.
The flues are suitable for rear, side and top exits.
There are two types of air source heat pump – ‘air to air’ and ‘air to water’. The Grant Aerona uses an air to water system which utilises heat energy captured from the air in ‘wet’ heating system radiators or underfloor heating. The process uses the same vapour/compression cycle that extracts heat in a domestic fridge. A refrigerant with a low boiling point is exposed to external air temperatures in an evaporator. The liquid boils off to a gas and absorbs the latent heat energy of the air. This gas is then compressed increasing the heat content in the refrigerant, before passing through a heat exchanger where it condenses back to a liquid state while transferring the heat to the water of the heating system. The liquid refrigerant is then re-circulated through the evaporator and the cycle is repeated.
The heat source used by Grant Aerona³ heat pumps is entirely renewable which helps reduce the amount of harmful greenhouse gases being released into the atmosphere and, in so doing, lowers the carbon footprint of the household.
Air source heat pumps must be correctly sized to ensure that it can provide the required amount of heat output at the design conditions – typically when the outside temperature is at -3°C. To do this an installer must first accurately determine the heat loss from the property and then, using this information, correctly select the required size of heat pump based on the design outside air temperature. Grant will also assist with sizing the ASHP and the Heatloss of the building.
The heat loss from the property must be determined from a full room by room heat loss calculation for the property concerned and not from:
The output of the previously used gas or oil fired boiler
An estimated heat requirement based on the floor area or building volume
The use of a simple heat loss calculator (e.g. Mears calculator)
The Energy saving Trust ‘Whole House Boiler Sizing’ simplified calculation method
The declared heat outputs for all ASHP’s are based on the average UK outside air temperature of 7°C. However, as mentioned above, a suitable ASHP has to be selected that will deliver the required heat output at the design outside air temperature (typically -3°C) when there is less heat energy in the air for the ASHP to draw from. At -3°C, the output of the ASHP will be reduced (typically to around 80% of the declared output). It is this lower heat output value that must be used when selecting the size of ASHP to be installed. The installer should ensure that any proposed ASHP system has been correctly sized and the unit selected in this way before proceeding with the installation.
Grant Aerona³ air source heat pumps are guaranteed for 5 years from the date of installation, unless the installation is more than six months from the date of purchase in which case the guarantee period will commence six months from the date of purchase. The guarantee period will be a total of three years (excluding consumable items) if the product is registered within 30 days from installation, subject to being serviced annually and installed in accordance with the manufacturer’s instructions. On completion of the installation, the heat pump must be commissioned and submitted to Grant Engineering Ireland Ltd.
Grant has a range of stainless steel cylinders specifically matched to the Aerona, which incorporate a larger primary coil for quicker heat transference. The cylinders are available in three indirect single coil versions, ranging from 200-300 litres and two indirect twin coil versions from 200-300 litres. Grant Heat Pump cylinders feature compression fittings which are conveniently located to make installation quicker and easier.
The north face of a building will usually have colder ambient air than any other side so, to ensure maximum efficiency from a Grant Aerona heat pump, position the unit on a warmer side, preferably south facing.
Grant’s latest ASHP uses R32 refrigerant which has a GWP which is considerably lower than other typical heat pump refrigerants such as R410, thus complying with the upcoming legislative targets. In addition to having a lower GWP figure of 675, R32 is a single-component refrigerant which means it has no temperature glide. Refrigerant blends that have two or more components exhibit temperature glide but as R32 only has one molecule in its formation, its saturated liquid and vapor temperatures are the same. By removing the risk for the refrigerant to suffer from glide, the system can recharge and recycle with greater ease, making it more efficient.
The coil of an existing cylinder will almost certainly be too small and this will result in longer cylinder reheat times at the lower water flow temperatures from a heat pump. For best performance a Grant High Performance cylinder should be used. This has a larger coil to reduce reheat times.
Grant heat pumps should be serviced annually. Failure to do so will invalidate the product guarantee.
Underfloor heating is generally installed into new builds since new floors are being installed. Underfloor can be retrofitted into existing building if existing floorboards are being lifted or new floor compositions being installed.
Yes, but usually they would be mixed on separate floors i.e. underfloor on the ground floor and radiators on the first floor.
No, the pipework would be pressure tested. Once it is confirmed that all pipework and connections are good then the concrete screed is poured. This is allowed to dry naturally for up to 30 days depending on thickness. Heat can then be introduced to the pipework at a low level and then slowly increased on a daily basis to required level.
No, the pipework would be pressure tested. Once it is confirmed that all pipework and connections are good then the concrete screed is poured. This is allowed to dry naturally for up to 30 days depending on thickness. Heat can then be introduced to the pipework at a low level and then slowly increased on a daily basis to required level.
Ideally the floor surface will be in the region of 24-27°C depending on desired room temperature. Floor surface temperature should not exceed 29°C.
Yes, this can be achieved by zoning of the house. Individual loops of pipework can be ran to each room and controlled by an individual thermostat. The quantity of heating zones can be determined at design stage.
Yes underfloor can be used with high temperature systems such as oil boilers and wood pellet boilers, a mixing unit will need to be added to the underfloor manifold to mix down the temperature to 35-40°C.
It is best practice to leave UFH stat controlled. When the room temperature drops below the set temperature a signal will be sent to the heat source. The heat source will then activate and bring room temperature up to required level. It is more efficient to maintain a rooms temperature as opposed to reheating rooms.
The manifold should be located as centrally as possible so as to reduce pipe run lengths and also to eliminate waste heat lost in distribution.
UFH is generally not installed underneath fixed items such as kitchen units, built in wardrobes, stairs, sanitary ware or showers/baths. These units are usually bolted to the floor and can damaged the pipework hidden below the screed surface.
UFH will work with most floor coverings, although some coverings work better than others. Some of the better working floor types include ceramic tiles, polished concrete, stone, engineered boards and carpet (with a TOG value of less than 2).
UFH does not rely on air circulation to disperse heat throughout a room, as the entire floor is radiating heat, an even dispersal of heat is given to all areas of the house eliminating any cold spots.
Wood pellets are cylindrical in shape and generally made from compressed sawdust, which is often the waste product from industries (e.g sawmills). They are fused by the natural lignin present in dry wood. It strengthens the wood as well as having water proofing properties.
All pellets used must meet ENplus standard EN14961-2 and be bark and sand free and must be approved by Grant before being used in the current Spira boilers. Failure to use approved pellets will invalidate the product warranty.
Moisture content below 10%
Calorific value of 4.8 – 5.2kWh/kg
Ash content of <1% (Low)
Bulk density of 650kg/m³ or less
Chlorine content of 0.03% or less
No additives
Using pellets which are not approved by Grant will void your boiler warranty. If you are in any doubt, please contact Grant before purchasing your pellets.
As the sawdust used to make wood pellets is a by-product e.g. from sawmill industries, or has been sourced from a managed forest where trees are planted to replace the ones cut down, they are classed a sustainable ‘carbon neutral’ source of fuel.
Yes. Wood pellets are available from a number of manufacturers and specialist suppliers. Also, some of the larger Plumbing and Heating merchants are now stocking wood pellets.
Pellets are available in both bagged quantities – usually in 10kg bags – or in bulk. The minimum bulk pellet delivery is typically 3 tonnes but this needs to be checked with the supplier concerned, as smaller deliveries may be possible.
There are a wide range of wood pellets, of differing qualities, available on the market. Only 6mm diameter pellets should be used in Grant wood pellet boilers. These pellets must first conform to EN plus standard EN14961-2.
Currently, Grant have tested and approved Balcas ‘Brites’, Laois Pelletts (GWP) and Premium Pellets for use with the Grant Spira wood pellet boilers. The use of pellets not conforming to the foregoing EN standard, may cause operating problems with the boiler and would invalidate the product warranty.
If the indoor pellet hopper (supplied with the boiler) is the only form of storage used then this will need to be filled manually with pellets supplied in bags. The hopper has a maximum capacity of 110kg or, eleven 10 kg bags of pellets.
If a bulk pellet store is used to feed the pellet hopper, the hopper will be filled automatically from the bulk store. Of course, it is important to regularly check the bulk store and to order a bulk delivery before it is empty.
If the indoor hopper only is used, then the boiler will automatically stop when the pellet level in the hopper reaches minimum. There is a facility to have a warning light to indicate when this minimum level of pellets is reached. Topping up the hopper with pellets will automatically re-start the boiler. However, to avoid this happening, the pellet level in the hopper should be regularly checked and topped up as required –usually once to twice a week.
If a bulk pellet store is used, then this will automatically top up the indoor pellet hopper. However, the pellet level in the bulk pellet store must be regularly checked and a delivery of pellets ordered before it becomes empty. The time between deliveries will depend on the size of the bulk store, the size of the boiler and how it is used. Typically, for a 26kW boiler around 3 tonne of pellets should last for about a year, based on a heating demand of 14,400kW input.
Wood pellets should always be stored in a damp free environment. Care must be taken to ensure that stored wood pellets never come into contact with water. Any external stores must be sealed and protected against rainwater entry. Grant market a range of internal and external pellet storage solutions, but advice on the type and location of bulk pellet storage is also available from the pellet suppliers.
On start up the auger feeds the wood pellets from the hopper into the burner where it is lit by an ignition element. The burner output is adjusted automatically (modulates) to achieve the set temperature by controlling the feed rate of pellets. The fan in the burner propels hot gas generated from the fuel into the Spira’s primary heat exchanger. The heat energy is then transferred to water from the central heating system, before being circulated around the house to either radiators and/or underfloor heating.
The noise from Grant wood pellet boiler comes from the following main sources; the flue fan, burner fan, self-cleaning process and the pellets themselves dropping into the burner. Whilst the combination of these is not excessively noisy, the Spira would be unsuitable for installation within ‘habitable’ rooms of a house, e.g. kitchen, utility room etc. which are more commonly used for locating conventional oil and gas boilers.
Suitable space must be allowed around the boiler for servicing and maintenance. Full details of the precise minimum clearances are to be found in the Installation and Servicing instructions provided with the boiler.
Typically, an overall floor area of 1700mm wide x 1500mm deep will be required to locate the boiler/hopper and provide the clearances required.
No. Grant Spira wood pellet boilers must be installed in a damp free environment along with the accompanying pellet hopper. The boiler can be located in an outbuilding, etc. but must not, under any circumstances be exposed to the elements (e.g. located under a car port or lean to canopy).
Yes. The base must conform to the requirements of Building Regulations. Full details are given in the Installation and servicing instructions supplied with the boilers.
Grant Spira wood pellet boilers can be used with 2-pipe, fully pumped hot water heating systems – either open-vented or sealed system – using radiators and/or underfloor heating.
Sealed heating systems must incorporate a suitably sized expansion vessel, a pressure gauge and approved filling loop. The 2.5 bar pressure relief valve required is supplied with the boiler.
Grant Spira wood pellet boilers can be used with most commonly installed domestic heating control systems, e.g. Y-plan and S-plan type control systems, where a programmer and room thermostat will control the operation of the boiler to the requirements of the householder.
Yes, provided that the existing system is chemically cleaned and flushed, and complies with current Building Regulations. The existing control system may also be used providing that it also complies with these regulations. If not the system and/or controls will need to brought in line with these requirements.
As with all boilers, a full heat loss calculation for the property should be made to determine the heat load that the boiler will be required to meet, under design conditions. If the heating system includes a circuit to a hot water cylinder then an allowance for water heating should normally be included in determining the final heat load to be met by the boiler.
During combustion a proportion of the heat produced is locked up in the flue gas. A conventional boiler cannot recover any of this heat and this energy is lost to the atmosphere through the flue.
The Grant SPIRA Condensing wood pellet boiler contains an extra heat exchanger which is designed to recover this heat normally lost by a conventional boiler. It does this by cooling the flue gases to below 90°C (Typically conventional boiler flue gases are 200°C plus) thus extracting more heat. This is achieved by cooling the flue gases to their dew point.
The Grant Spira is a condensing wood pellet boiler with a modulating burner and has exceptionally high efficiency levels. The 6-26kW model has a tested and approved full load efficiency of 97.4% and the 9-36kW model 93.1%.
This is comparable with high efficiency condensing domestic oil fired boilers (and better than many high efficiency gasfired boilers), making the Grant Spira both an energy efficient and ‘Green‘ alternative to fossil fuel burning boilers.
Grant Spira wood pellet boilers benefit from the use of award winning condensing technology, originally developed for Grant’s market leading Vortex oil-fired boiler range. This, in conjunction with the all-new fully modulating pellet burner, has resulted in an extremely efficient range of renewable home heating appliances. Higher efficiencies, coupled with lower and more stable fuel costs, creates a very environmentally and consumer friendly heating solution.
Only Grant trained and accredited wood pellet boiler installers can install the Grant Spira wood pellet boiler. Courses are available via the Grant Training Academy and can be booked by calling (057) 912 0089.
In order to ensure efficient and safe operation, Grant Spira wood pellet boilers must be serviced annually when amongst other things, the primary and condensing heat exchangers, combustion chamber, flue fan box and burner, must all be cleaned of any ash deposits and the burner re-set for a further year’s operation. The boiler will indicate when this is due, by displaying a ‘SERVICE’ message on the burner control panel. This service interval is based on the actual running time of the burner and thus may vary in length depending on the degree of use of the boiler.
The efficient combustion of the Grant Spira burner, coupled with the consistently high quality of the wood pellets approved for use with the appliance, results in a relatively small amount of fine ash being produced within the boiler. The majority of this will be collected within the easily accessible ash pan located inside the combustion chamber.
Furthermore, as the Spira incorporates automatic cleaning of both the primary and condensing heat exchangers, and the burner brazier, at pre-set intervals to remove any ash deposits, they generally only require manually cleaning out around once per year i.e. the ash pan requires emptying, or after about 3 tonnes of pellets have been burnt.
Yes, all boilers within the Grant Spira Wood Pellet Range are MCS approved.