Do you need a compact solution that doesn't compromise on power? Look no further. Specify or install our Evo S stainless steel wall-hung condensing boilers, in outputs of 40–70kW on our low-height frame and header kits, for the smallest cascade footprint on the market. 

Perfect for projects where location and space can present a challenge, Evo S offers a compact solution - models up to 70kW measure just 487mm wide x 577mm deep x 764mm high. What’s more, when installed on one of our low-height frame and header kits, the total height from the floor to the top of the flue connection is just 1474mm, making Evo S an ideal fit for plant rooms with restricted headroom. This also makes Evo S particularly suitable for replacing older non-condensing floor standing boilers without the complication of an increased installed height to accommodate. 

More than just space-saving 

Evo S delivers more than just compact dimensions.  Installing an Evo S cascade brings several benefits over relying on a single large boiler to heat a building.  For instance, whereas a single appliance trying to supply heat to a large area carries the risk of oversizing, which can result in excessive use of fuel and increased wear and tear, an Evo S cascade system allows multiple boilers to work harmoniously together for an efficient and flexible solution.  Additionally, it provides added protection against breakdown. 

This was a key factor for William Freer Limited when they were tasked with delivering a space-saving and reliable heating system for a church in Leicestershire. The team installed three Evo S boilers in cascade, using a low-height frame and header kit, with a plate heat exchanger for hydraulic separation.  The result? A dramatically reduced plant footprint and a highly efficient, cost-effective heating system that’s easier to service and maintain, now and in the future. 

Efficient, reliable, and future proof   

Whether for new build or retrofit applications, Evo S cascades offer outstanding efficiency. Each boiler features a 5:1 turndown ratio, Class 6 low NOx emissions, and up to 97% gross seasonal efficiency. The robust stainless steel heat exchanger ensures long-term durability and high system tolerance, supported by a five-year heat exchanger warranty for added peace of mind. 

To further protect boilers when installed on existing systems, our latest Plate Heat Exchangers (PHEX) offer enhanced boiler protection and performance. 

Plan your cascade with ease. 

To simplify specifications, use the Evo S Cascade Builder tool. Just answer a few short questions to receive everything you need to configure the perfect Evo S cascade system for your next project.