Reduce heating energy consumption and carbon emissions NOW!

EndoTherm is an easy to install, award winning, energy saving additive suitable for any wet heating system that is proven to save up to 15%

Large library of customer verified pilot studies

Supported by Energy Efficiency Rebate & Funding Schemes

Featured in International Journal of Energy Management

Focused on by BC Housing Energy Efficiency Research

EndoTherm – Energy Saving & Carbon Emission Reducing Hydronic Heating System Additive

EndoTherm is a unique, multi-award winning energy saving hydronic additive independently proven to save up to 15% on space heating energy consumption.

Systems Heat Up Quicker…

Improved Heat Transfer…

Using Less Energy!


Independently Proven

EndoTherm has been rigorously tested with savings confirmed by multiple third party Research & Development laboratories and facilities.


Easy to Install

EndoTherm requires no system downtime and can be installed, like an inhibitor, in just 10-15 minutes.


Non - Corrosive

EndoTherm is non-corrosive to heating system components in use and is non-hazardous with no discharge requirements.

Award Winning & Recognised

EndoTherm is a multi-award winning technology with confirmed compatibility with leading boiler and inhibitor brands.

Carbon Emission Reduction

As EndoTherm reduces heating energy consumption, greenhouse gas emissions are also reduced which is vital to achieve net zero targets.


100% Organic

EndoTherm is made from 100% organic materials and is responsible for 0.58Kg embodied carbon which is offset in under a day of use.

Laboratory testing, and studies carried out in samples of domestic and non-domestic properties, shows that EndoTherm has been effective in reducing energy and fuel consumption with condensing boilers *

*These results are specific to the cases studied. Similar performance improvements may not be realised in other heating systems. Potential performance improvements depend on the current performance, condition and settings of the heating system. Based on performance data and instances reviewed comprising results from Enertek test report E3363 (dated 14th January2014); RCT Homes field trial report from Artega and non-domestic case studies.
EndoTherm-Verified by Energy Savings Trust

EndoTherm has confirmed compatibility with these major boiler manufacturers:

*EndoTherm does not invalidate the warranties of these boiler manufacturers

In partnership with:

CIBSE - Energy Saving Product of the Year 2016
CIBSE - Energy Saving Product of the Year 2016
H&V News Awards 2015 - Domestic H&V Product of the year
Ecobuild M&S Big Innovation Pitch Winner
EndoTherm central heating additive also available at Nigels Eco Store
EndoTherm central heating additive also available at Nigels Eco Store

EndoTherm is featured in the October 2021 issue of the International Journal of Energy Management:

EndoTherm is a recognised technology supported by HVAC rebates in a number of territories:

HVAC Control

EndoTherm Supported by HVAC Control Rebates

EndoTherm is now supported by HVAC control rebate schemes.


Find out more about how you can take advantage...


A Message From Our Managing Director:

It is very clear that tangible action has to be taken immediately to tackle climate emergency, achieve net zero carbon goals, and combat rapidly rising energy costs.

EndoTherm presents an extremely attractive, cost effective opportunity, to quickly reduce space heating energy usage by double digit figures. Our team is on hand and ready to help you.

How EndoTherm Works

EndoTherm is a unique energy saving central heating additive, independently proven to save up to 15% on heating bills! But how does it work?

Contact Us

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EndoTherm Presented at US Department of Defense Energy Efficiency Symposium

Dale Edginton, the North American Operations Manager for EndoTherm, recently had the honour of presenting at the Department of Defense's (DoD) Energy & Environment Innovation Symposium; a gathering...

Thrive Homes Partners with Endo Enterprises to Provide Heating Energy Savings for Tenants

Thrive Homes, a leading housing association in the UK across Hertfordshire, Bedfordshire, Buckinghamshire and Oxfordshire, has announced a new partnership with Endo Enterprises to provide and...

Californians Get More from Your Hydronic Heating System with a Free Energy Efficiency Study

Is your commercial or multifamily building heated by a hydronic system that uses natural gas? Is your building a SoCal Gas, SDG&E or PG&E natural gas customer? If so, you may qualify for a no-cost...

Carrier Air Conditioning Confirm Equipment Compatibility with EndoTherm

We are excited to announce that Carrier Air Conditioning, a global provider of innovative heating, ventilating and air conditioning (HVAC), refrigeration, fire, security and building automation...

Solent NHS Trust Rolls Out EndoTherm

We are excited to announce that our energy-saving additive, EndoTherm, has been installed in multiple hospitals and healthcare buildings across the Solent NHS Trust estates portfolio. Working with...