Here we find ourselves down a rural unmarked lane in Kent, the site of a large barn conversion.

Exterior of Barn

It comprises a two storey hallway, and many original features.

Much of the house is already underfloor heated, using an L&K system with around 14 separately controlled zones.

Halfway through rewiring this lot of underfloor heating

What makes this system unusual is the various heat sources used to create the heating and hot water. There’s two fuel burning stoves, some solar thermal on the rooftop, and a Rayburn solid fuel stove.

We reused the Rayburn chimney, modifying the Selkirk components above the cooker

This was all installed by the present owners, who were almost singlehandedly responsible for the design and execution around 14 years ago. They made a very professional job, too.

Being 14 years younger at the time, the idea of using renewable energy was attractive, and their location had plentiful supplies of timber for the stoves.

Now the honeymoon of chopping logs, drying them out and moving them into the house was beginning to pall. The solar panels, whilst creating around 50% of their hot water requirements over the year, only save around 7.5% of the annual energy bill, because heating is responsible for around 85%.

They had even installed a separate electric boiler a few years ago, but this had been ruinously expensive to run. No surprises there; at the time of writing (January 2020) electricity is over double the cost of oil. Or gas.

The thermal store, denuded of components

Our customer had used a thermal store to amalgamate all the different energy sources, and provide hot water. The store had seen better days, and was a basic type with a coil rather than a plate heat exchanger, and this was giving a poor performance.

This is a 14yr old Rayburn stove. Wheels are extra.

Our customer had seen a Heritage cooker at a friend’s house, and wanted an oil fired one for their house.

We designed a new system that used a Heritage cooker, complete with a internal 30Kw boiler, to replace the Rayburn stove and the various other heat sources.

Heritage Duette Compact (ovens are the right hand doors)
Iron Cooker lids (chrome ones also an option)

We swapped out the thermal store for a solar compatible Fabdec Self Sustaining 3S unvented cylinder. This immediately and visibly improved the hot and cold water performance compared to the thermal store.

The Fabdec cylinder, from the inventors of Megaflo, incorporates the latest technology to recharge it’s own air gap. Expansion vessels are no longer required, and unlike the Megaflo, there’s no airgap that need periodically recharging.

Solar and boiler inputs

We had to order a unique cylinder for this job; it was the first Fabdec 3S solar compatible cylinder to be fitted.

The cooker was a Heritage standard Duette. it comprises a cast iron frame with modern pressure jet burners inside. For a heat store oil fired cooker, it is quiet, and very fast to warm up.

Cooker and Hot Water controls here……..

It has a digital timer so it can be ready when you get home, typical warm up from cold to cooking is less than half an hour. Read this and weep, AGA owners. PS: If you have an oil fired AGA, get this, if you turn the Heritage off, it will come on again!

This particular Heritage has two full sized ovens, plus a boiler inside. The functionality of the boiler is completely separate to the cooker. The only things they share are the flue and the casing.

Steel bunded oil tank with secure fill point

A new bunded steel oil tank was installed outside, there was a lake nearby so no chances were taken with the tank specification. Steel oil tank degrade gracefully, leaving the owner with plenty of warning when their lives are nearly up. Plastic moulded tanks give little warning of impending failure, and are also easily damaged by air rifles, and collateral damage from attempted oil theft.

New oil filters and safety fire valve. Silver cowl is boiler and cooker combustion air inlet.

Heritage Cookers are based in Liskeard, Cornwall.

We’ve got a fair bit of experience with them; I installed ours back in 2004, and it is still used every day.

Simon’s Heritage cooker, 16 years old. Must put the milk bottles out.