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Oil boilers

Why is a renewables company offering installation and servicing of oil boilers?

Great question! We'll explain...

Oil boilers are great at providing high flow temperatures for heating, and oil has one of the highest energy densities of common heating sources. Why change in that case? For one, the environment – they produce a lot of CO2 for the heat they produce.

Historically, the only cost-effective options available to provide central heating were oil or LPG. So, if you want to move away from oil or LPG, what are the options? You could put in a heat pump – there are some considerations though. Most heat pumps work at a lower flow temperature than oil boilers. Conventional heating systems are designed to run at a boiler output temperature of around 70°C to 80°C, meaning the pipe and radiator sizing is set for that temperature. The original system design is key to the cost of adding a heat pump, and heat pumps have, until recently, been unable to produce flow temperatures in this range; generally, they produced a maximum flow temperature of around 55°C. Also, as the flow temperature of the heat pump is increased, its SCoP reduces. For some properties, this may not be an issue because the pipes and radiators were oversized in the original installation, but for others it will be.

One potential solution is to have a ‘bivalent’ or hybrid heating system. A bivalent system is where the property retains the original heating system but has the addition of a heat pump. The heat pump provides heating and hot water up to the point where the outside temperature is so low that the heat loss exceeds its capability. At this point, the oil boiler takes over as it can supply a higher flow temperature.










Where possible, we try to keep capabilities in-house to retain control of the process, quality and costs for our customers. To modify existing oil boiler systems to incorporate a heat pump requires the ability to modify existing systems. Achieving this also gives us the ability to design, install and service oil heating and storage systems. While this does not totally remove the generation of CO2, it does reduce it.


We believe it is better to take some gain rather than none at all. This bivalent solution also reduces the amount of oil used, reducing fuel costs.

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