Lambda Log Boilers

Built with large fireboxes, you can use logs up to 500mm long in your Lambda boiler

Effecta: Lambda Log Boilers

This range of 25, 35 and 60kW log boilers is as contemporary as it is innovative. Built with large fireboxes, you can use logs up to 500mm long in your Lambda boiler. And thanks to the large grate and the efficiency of combustion, you won’t need to fill your boiler up too often. 

The Family of Effecta Lambda Boilers

Key Features

  • Heat outputs 25, 35, 60kW.
  • Lambda controlled with automatic dampers.
  • High efficiency and low emissions.
  • Available with side mounted (60kW) pellet burner.
  • Also available with front mounted (25, 35kW) pellet burner.
  • Large fire grate 100/145/195 litres.
  • Easy for the whole family to use.
  • Adjustable and reversible doors.
  • Optional; cleaned when door opened.
  • Cooling coil.

Log Gasification

This model gasifies logs at around 600°C in the loading compartment and, as the hot gases travel down through the ceramics, secondary air gets introduced, burning the gases at double the temperature: 1,200°C.

Cutaway Diagram of the Lambda Boiler

Future Fuel Flexibility

Boilers in this range can be designed to burn logs or pellets, giving the user total fuel flexibility. Choose from front or side-mounted to give outputs of 25kW and 35kW respectively. 

The Effecta Lambda Boiler and Logo

A side mounted wood pellet burner can be installed to give heat ouptuts of 25kW or 35kW. A front mounted wood pellet burner can be fitted to give heat outputs up to 60kW. ​

Preparation for wood pellet burner

Beautiful Design

Designed with the unique simplicity for which Scandinavian manufacturing is famous, you’ll find the finished look of the Lambda totally timeless and perfectly in tune with your boiler room. 

The design of Effecta's Lambda boiler


Lambda boilers below 45kW are all MCS accredited and therefore compliant with domestic RHI applications. 

MCS approved - Made in Sweden - 93% efficiency

Reduced Emissions

In order to achieve MCS accreditation, Lambda boilers have been designed to have emissions significantly lower than the required limit of 30g/Gj particulates (PM) and 150g/Gj of nitrogen oxide (NOx).

Meeting (and beating) these standards means that the Lambda is perfect for commercial or domestic RHI projects. 


Maximum Emissions 30 g/GJ 150 g/GJ
Effecta Lambda Log Boiler 25 9.7 g/GJ 138 g/GJ
Effecta Lambda Log Boiler 35 13 g/GJ 91 g/GJ
Effecta Lambda Log Boiler 60 19 g/GJ 80 g/GJ

Accumulator Tanks

All Effecta boilers are designed for use with an accumulator tank which stores energy, ready for when it’s required. Depending on the Effecta model, the accumulator tank should have 1,000, 1,500 or 3,000-litre capacity. 

Accumulator tanks

Air Introduction

Getting combustion efficiency right can be tricky, which is why Effecta have poured years into perfecting their boilers. Each model has a lambda sensor, which works to produce consistent firing, optimum combustion and low emissions. This intelligent sensor also tells the boiler how its combustion is running.

The Lambda Control Sensor


Your Lambda boiler comes with an easy-to-use, touch screen management panel, giving you total control and calculating your boiler’s temperatures to within a degree of efficiency. 

The Lambda boiler control system

Lambda Overview Video

Effecta Lambda Key Feature Tour

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Technical Specifications

    25kW 35kW 60kW
Height mm 1,170 1,280 1,340
Width mm 570 600 750
Depth incl Smoke Outlet mm 1,050 1,260 1,330
Depth of Grate mm 450 550 550
Volume of Loading Compartment Litres 100 145 195
Floor to Centre of Smoke Pipe mm 1,200 1,290 1,365
Dimension of Elbow mm 150x150x630 150x150x630 150x180x630
Smoke Outlet Diameter mm 130 140 180
Weight kg 350 400 540
Boiler Volume Litres 70 90 135
Minimum Flue Area Diameter mm 130 130 180
Max Log Length mm 500 500 500
Power Consumption VAC 230-50Hz 230-50Hz 230-50Hz
Connection to Pipes Inch 1 1 1/4 1 1/2
Connection to Drain Cock Inch 1/2 1/2 1/2
Efficiency % 93 92 91
Max Working Pressure Bar 1.5 1.5 1.5
Max Working Temperature oC 100 100 100



What is the calorific value of logs?

5.1 kWh per kg, depending on the moisture content of the logs.

What kind of logs should I burn?

Logs need to be sustainably sourced, as dry as possible and have no coatings or preservatives. Only use logs that have been seasoned for 1-2 years before use in your biomass boiler. The moisture content needs to be 20%, otherwise energy is wasted burning off moisture, meaning your boiler isn’t as efficient as it could be.

How long do logs take to dry?

Hard woods need longer to season - around two years. Soft woods need around one year. The ideal size is 500cm long and 12-15cm thick.

Where can I find a good log supplier?

We always recommend using the fantastic Biomass Suppliers’ List (BSL) for a comprehensive list of high quality suppliers across the UK.

How much should pay for logs?

Logs will cost you approximately £90 per tonne.