Understanding the needs of your Wood Pellet Boiler
Are you contemplating changing from a fossil fuel boiler to a wood pellet boiler? If you are, it’s well worth understanding how it works. A basic knowledge of the inner workings of a biomass boiler will help you to ensure that the system you have installed will meet your expectations and deliver the flexibility and warmth you’re looking for.
What are your options?
The size and age of your property, will determine what type and size of wood pellet boiler you will need to meet your family’s needs for warmth and hot water. As with any major household renovation it is always advisable to get several opinions and quotes for comparison.
When looking for an installer, don’t be afraid to ask questions. This is an installation you will have to live with for the next 20 years. Check that they are experienced and can provide you with a similar installation to go and look at. Ensure they understand what you are expecting from the system; click here to see other important questions to ask.
How does a Biomass Boiler work?
In very simplistic terms your boiler works by taking the wood pellets from the hopper (which can be fed either manually or automatically) into the boiler at a set rate, where it is burned in the combustion chamber. The amount of heat that is produced is controlled by the rate at which the pellets are fed into the chamber. Thermostats placed in zones around the house will control the level of heat in each area, allowing you to control the room temperature according to your needs in the same way as a traditional oil/gas boiler.
As with any combustion process there are waste products, and in this case they are ash and flue gases. The flue gases will be expelled via the chimney automatically (what is expelled is tightly controlled), however the ash will need to be removed from the ash draw on a regular basis. The amount of ash the boiler will produce is obviously proportional to the amount of wood pellets burnt, but less obviously, it is directly related to the quality of the pellets. 5 tonnes of ENPlus pellets will produce no more than 5kg of ash.
When looking at the hopper options, there are two basic types, hand fill or automatic and they each have certain limitations. The automatic hopper will take wood pellets from a fuel store that will need to be located near the boiler; this option works well if you have out buildings that can be used. Automatic hoppers will also increase the cost of the system. If space and or cost are an issue then a manual feed hopper can work perfectly well. The only drawback maybe the need to lift and empty the bags of pellets into the hopper; pellets are available in 10kg for ease of use. It is not unknown for a staged approach to be taken with an installation where the boiler is first installed with a manual hopper, which is then upgraded to an automatic hopper when funds, time and space allow.
As with all boilers, irrespective of fuel type, it is necessary to get the boiler serviced at regular intervals to keep it working efficiently and to avoid unnecessary breakdowns. In order to claim your RHI your boiler must be in good working order.
Where will it be installed?
Again, this depends on the size and shape of your house, but it will generally be a direct replacement for an old oil or gas boiler, so will go in the same spot. There are a few other things to consider though:
- More space – a biomass boiler will take up more space than a traditional boiler, the amount of space available may dictate the type of wood fuel delivery you can have: bag vs bulk.
- Type of hopper – as we have mentioned previously if you have space near the boiler you might choose to have a bagged delivery, which will mean you will have to load the hopper by hand. If you have an easily accessible outbuilding that can be converted to bulk wood pellet storage then this can feed into the wood pellet boiler automatically, no lifting required.
- A chimney or flue – the boiler will also require a chimney or flue that is designed for wood fuel. You may also need planning permission to make alterations to your house, and you will need to check whether you live in a smokeless zone or not.
- Delivery access – with both bulk and bagged deliveries, lorries will require access to turn and unload. The nearer they can get to either the bulk hopper or pallet storage shed the better and easier life is.
To purchase high-quality wood pellets to fuel your boiler, check out our Woodlets purchase page here.