New Central Heating Boilers today are the most energy efficient that they have ever been. A new A-rated high efficiency condensing boiler will boast an efficiency rating of around 90%. However, a lot of heat is still lost through the flue outlet.

A new innovative product has been designed to capture this heat and use it to help generate hot water for domestic use. Designed and manufactured in Britain, the Zenex GasSaver delivers more usable hot water than a typical solar hot water system.

The GasSaver is attached to the top of a domestic boiler and works by capturing waste heat from the exhaust gases to warm the water in the tank. These are then passed through a flue and pumped back into the system, which preheats the cold water entering the boiler.

The temperature of this water is kept below 50 degrees, giving an increase in efficiency over typical condensing boilers, whose performance drops if the water is above that temperature. The result is a boiler that uses less energy.

Installation should be relatively straightforward, a basic knowledge of plumbing should suffice. Another bonus is zero maintenance (no moving parts) or electrical supply (no electrician). New-builds and total refurbs may be the GasSaver’s natural home. It may prove difficult to install onto existing boilers, unless you are prepared for a bit of hassle. Another consideration maybe the GasSaver’s unsightly apprearance. Aesthetics shouldn’t really figure when saving money (and the planet) but the unit does look a little uncomfortable atop the boiler.

According to the manufacturers, the cost of the unit could be recovered within three to five years (compared to 20-40 years for Solar!) With energy prices anticipated to rise by up to 25% in the next five to ten years installing a GasSaver (which could save you 50% on your gas bill) may prove a wise investment.

Buying a GasSaver

The manufacturers of the GasSaver have licensed their products to leading boiler manufacturers Alpha Boilers and Baxi Boilers.

The Baxi MultiFit GasSaver currently works with the Baxi DuoTec and Baxi Platinum combi boilers.

3 Responses to “Save energy with a Boiler Gas Saver”
  1. [...] Baxi Ecogen, from Baxi is a combined heat and power appliance (CHP) generates electrical power and useful heat from the single source. The model displayed above explains it all. Baxi also displayed the Zenex built GasSaver, which I discussed in a previous blog post, Save Money with a Boiler Gas Saver. [...]

  2. Simon Whysall says:

    The Alpha Gas-Saver can also be installed with the Alpha Solar-Smart.
    Solar-Smart is a unique system that combines Solar with an Alpha Combination Boiler.

    The benefit of Solar with a Combi is that All the solar gain collected is used and can be topped up if needed “on demand”
    Add the Alpha Gas-Saver and you have a Year Round Gas/Carbon saving as Gas-Saver will pre-heat the Solar cylinder..

    For more infomation please visit


  3. John says:

    Alpha appear not to bundle in the GasSaver with the SolarSmart. The GasSaver could extract heat from a hot solar store.

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