Spira condensing wood pellet boiler

How the Spira works

On start up, the auger feeds the wood pellets into the burner where they are lit by an ignition element. The burner output 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 boiler’s primary heat exchanger. The heat energy is then transferred to the water circulating around the radiators/underfloor pipework of the heating system.

It is important to note that in most modern pellet boilers, up to 20% of the energy that is produced is lost to the atmosphere through waste gases exhausted by the flue system. Grant wood pellet boilers have a unique secondary condensing heat exchanger which has been designed to capture some of this lost latest heat energy so it can maintain extremely high efficiencies.

Siting of appliance

Wood pellet boilers must be installed in damp free environments. The Grant Spira is designed to be sited in a garage, store of outhouse (unless fitted within the Grant SpiraPod which is an outdoor boiler housing for the Spira allowing for external installations).

To enable the boiler to operate safely and efficiently, a correctly sized and permanently open air vent (open to the outside) should be provided in the boiler room. The boilers will carry out an automatic cleaning cycle at pre-set intervals and this process will result in a temporary increase in the noise level so this should be considered when choosing a suitable location. Bulk storage hoppers will require vehicle access for refilling so it is also important to consider where the boiler and its accompanying hopper will be located before purchasing.

Boiler Maintenance

A unique feature of the Grant Condensing Wood Pellet boiler range is that our patented technology results in the boiler requiring very little maintenance compared with other wood pellet appliances. Grant biomass boilers have an automatic self-cleaning system for the primary and secondary heat exchangers to ensure they stay free of debris. They also feature a self-cleaning burner. Using a Grant approved EN Plus Grade A1 wood pellet with low ash content minimises boiler maintenance as larger amounts of pellets can be burned before the ash pan requires emptying which can be up to 2 tonnes in some instances.

Fuel Storage

It is important to ensure that you have sufficient space to store the wood pellet fuel. A bulk storage system can be employed for greater pellet capacity (eg. 4 tonne store) and this be fed directly into the integral boiler hopper supplied as standard with the boiler. Access to larger stores should also be considered to allow for bulk delivery lorries to deliver. It is also worth ascertaining you pellet supplier’s minimum delivery quantity before selecting a store as this could help determine which size store is most appropriate.