09/11/2020
  • Boilers
  • Varmax
Varmax boiler up to 637 kW output

Hamworthy Heating has recently extended their range of Varmax floor standing condensing boilers to now go up to 637kW output from a single boiler, with the ability to cascade multiple boilers to match high demand heating projects.


A popular choice for heat networks due to its wider differential temperatures, the Varmax boiler is non dependent on system flow for safe operation. Thanks to an internal circulation loop and pump the boiler does not need to be installed in a traditional primary circuit removing the need to purchase and install ancillary equipment such as a low loss header and pumps. This not only saves time and money, but reduces the space required in the plant room.

For maximising condensing operation for best efficiency the boiler has twin return connections. This allows high and low temperature returns to come into the boiler in separate sections so you can return from a hot water circuit and a low temperature underfloor heating circuit, for example, without affecting the ability of the boiler to condense.

Andrew Dabin, Product Manager for Hamworthy Heating commented, “The Varmax boiler is a unique boiler in our product range. It helps our customers to match modern heating system design requirements as well as save costs and installation time on site. We’ve been selling it for more than three years and the recent extension of a single boiler up to 637kW output will help designers who are increasingly having to design for high heating demands from tight plant rooms.”

The boiler range features a fully stainless steel heat exchanger that is backed up by a 5-year warranty. The product is well insulated to reduce standing heat losses and can match system heating loads accurately with a 5:1 turndown ratio per boiler module.

The Varmax boiler comes as standard with the built in Siemens LMS control that is common across all Hamworthy condensing modular boilers. The controls are capable of sequencing up to 16 boiler modules, multiple heating circuits and a hot water circuit.

The higher output modules are available from 17 November 2020.

Check out the Varmax boiler technical specifications here.