St Paul’s Church is a busy community hub with numerous activities occurring throughout the week in addition to regular worship. The Church is an old, large and poorly insulated building.

The Church Hall, located adjacent to the Church, is a flat-roofed 1960’s building. Dunster was asked to provide an economically viable and practical biomass heating solution to replace the defunct mains gas boiler that heated the Church. A containerised system was chosen as no suitable building was available and the Church wished to minimise disruption on site. Preparatory site works included the casting of a concrete base for the container and laying 15m of heat main from the boiler to the Church basement. The plant room was delivered to site fully built with only minor works, such as erecting the flue and connecting to the existing heating systems, required after delivery.

System Design and Installation

The existing radiators have been retained in the Church and Hall but the mains gas boilers have been decommissioned with heat now delivered from the biomass system via heat exchangers. The old Church system had very basic controls with no modulation so was either ‘on’ or ‘off’ and delivered heat at such a rate that after a few hours it had to be turned off to prevent overheating. Inevitably, the Church then cooled down becoming too cold after a short time. The networked ETA controls provide weather compensated heating that can be set up in advance to heat the building for the periods required. Thermostats feedback the actual temperature to the boiler and can be used to adjust the required temperature and override pre-set heating times. The whole system is linked to the internet allowing remote adjustment and monitoring of the boiler. The system is designed to be operated for longer periods at lower temperature levels so helping to maintain the fabric of the building whilst improving overall habitability.


The environmental and economic benefits of the system both support the wider work of the Church and demonstrate its position as a responsible, community leading, organisation. It is anticipated that the inclusion of biomass heating will be a positive influence on the local planning department when it considers forthcoming plans to re-develop the Church Hall.


November 2012


Space heating for a large Church and associated Church Hall (St Paul’s Church)

Boiler and Plant

140kW ETA Hack wood pellet boiler installed in a purpose-built container with a 3,000-litre accumulator tank.


The boiler is expected to use approximately 45 tonnes of wood pellets per year to produce around 185,000kWh of heat.

Fuel Supply

Pellets are pumped through flexible hoses into the V-shaped pellet store at one end of the container. An auger running along the base of the store transfers pellets directly into the boiler. The store will hold around 12 tonnes of pellets when full and deliveries are made by rigid bodied road tanker.

Grant / Funding

The project was funded by the diocese and has received Renewable Heat Incentive accreditation.

Savings / Investment

Income from the Renewable Heat Incentive means that the investment should be paid off in under 5 years leaving 15 years with an annual net income of around £6,500 to support the work of the Church.

CO2 saving

Estimated at 22 tonnes per annum.

Our 90kw ETA Hack wood chip boiler suffered water damage in late 2014. Dunster Biomass Heating was the only company that could fix the issues without costing me new components. What we have learned is simple. Experience is key! When there is an unusual problem you need more than a guy with a manual – you need a company with the expertise, ability and willingness to solve the problem!

Nick Hiscox, Director, GSF Livestock Equipment