Connecting solutions

Integrating existing heating and hot water systems with renewables can often be problematic. So, when Paul Browes wanted to connect a new wood-fired central heating Rayburn with his pressurised oil-fired system, he found the perfect solution.
Paul Browes, who lives in a 16th-century farmhouse in Witnesham, Suffolk, was shocked when he calculated the annual oil costs of his ageing range cooker. Although it was only used for cooking, it was using over 400 litres of oil per month (approximately £200) with no way to reduce the consumption.
Instead of continuing on with the inefficient cooker, he set out to limit his reliance on fossil fuels and embrace a more sustainable way to heat his home. Paul looked to a wood-fired central heating Rayburn to replace the cooker and also supply a renewable source of heating and hot water. He then called in Chris Plant of Chris Plant Heating and Plumbing for advice on the models available, as well as the possibility of linking it with the existing oil boiler and a forthcoming solar thermal installation.
After 35 years in the trade, Chris – a Rayburn Guild member whose business is based in Framlingham, Suffolk – has plenty of experience installing central heating range cookers. He recommended the Rayburn 345W as the ideal model for Paul’s needs as it not only provided excellent cooking capabilities with the indirect, radiant heat from the cast-iron construction, but also more than met the heating and hot water requirements of the property. Chris then discussed the most effective approach to optimise the system for wood burning.
“The 345W was perfect for the heating and hot water requirements, but with renewable heating the priority, we still needed to maximise the Rayburn’s output and minimise use of the back-up oil boiler,” said Chris. “Paul had already set about researching the options and had discovered the Eco-Connect from AGA Rayburn. I knew it offered everything he was looking for and would be a great investment, so we discussed it further and looked at the system requirements.”
Although it has always been possible to design a shared plumbing system, there have been inherent problems with devices available to help heating engineers. For example, most modern automatic boilers are designed to operate with sealed pipework systems, but solid-fuel and wood appliances generally use a traditional open-vented system, making it quite a tough challenge to match the two systems together.
Seeking maximum benefit
Householders also want to get maximum benefit from using renewable energy, so the system needs to be controlled automatically where preference is given to drawing from the renewable source rather than the fossil fuel. The Eco-Connect panel solves all of these problems and makes connecting Rayburns, renewables and traditional systems a simple job.
Paul’s new installation ensures that the Eco-Connect favours the wood-fired Rayburn as the primary source of heating and hot water. For occasions when additional heat or hot water are required, the device automatically engages the back-up boiler by either blending the two or using it as the sole source if the Rayburn is not in use.
“When I first had the system installed it was difficult to estimate how often the boiler would kick in,” Paul explained. “As it happens, it’s only ever called upon if I have guests and the hot water demand is higher than usual – and even then it’s only for five minutes every hour. Day to day, we have it in Eco mode and provided we keep the Rayburn well-fuelled, it can act as theprimary heat source all year round, which means we don’t have to use the boiler at all.”
Eco-Connect works with a diverse range of systems, including solar thermal, boilers, central heating range cookers, thermal stores, heat pumps, underfloor heating, radiators and wood burning stoves. The system comprises a wiring centre, pump station and a heat exchanger with associated motorised valves to which the various flow and return pipework and electrical connections are made.
Thermistors are used in conjunction with an intelligent control panel to sense the water temperature of the flow and return pipes and domestic hot water (DHW) cylinder. It also incorporates a display panel showing the current operating status and which energy source is being used – e.g. wood-fired Rayburn or boiler.
Heat is diverted by the Eco-Connect to where it is needed – for example, the hot water cylinder and/or the central heating circuits. If the renewable appliance is not giving sufficient output, the fossil fuel boiler is brought into operation in a mixed mode.
However, if the homeowner has selected one of the ‘eco’ options, the boiler will not automatically fire. This is particularly useful for installations with solar thermal, so in Paul’s case, he incorporated a triple coil cylinder with a view to installing solar thermal panels in the near future. Once completed, he expects this to produce enough DHW for the property without needing the oil boiler at all.
Self-sufficient approach
David Carpenter, Rayburn’s Technical Director, said: “We know that Rayburn customers are a pragmatic and practical group of people who want to get the very best from their heating systems. However, with the cost of fossil fuels on the rise, we’ve seen many customers opt for a more self-sufficient approach with wood or solid-fuel Rayburns. Obviously, being able to link these products to an existing central heating system, or even include solar and wood burning stoves, is a great option and that’s why we developed the Eco-Connect panel.
“Paul’s set-up is just the sort of installation we envisaged for this technology and we are really pleased to see it working well and economically.”
Transforming home heating
Rounding up the success of the installation, homeowner Paul Browse described the improvements: “After a quick calculation, I was astonished at the savings I’d made. We barely use oil anymore and the Rayburn really has transformed the way we heat our home.
“From an installation point of view, it initially took some careful planning, but was simple enough to incorporate into the existing system. And with the Eco-Connect panel already pre-set with operating modes, I haven’t really had to think about it since. All in all we couldn’t be happier.”
For more information please visit, : www.rayburn-web.co.uk