Baxi EcoBlue & EcoBlue Advanced Heat Only Boilers

25 Apr. 2019

Written by Neil Marsh MCIPHE RP RHP EngTech


In this article, we will be discussing the latest Baxi EcoBlue Advanced and EcoBlue heat only boilers, of which are pretty much the same boiler, except the Advance has a 7-year warranty, whereas the standard EcoBlue Heat is 7-years …


We do not feel this boiler represents good value for money. In our opinion, there are many better-made heat only boilers for a similar cost or even less. The warranty does give it an edge compared to some, but we feel this boiler has some significant design issues which could be costly to maintain and that could lead to the EcoBlue boilers being replaced more frequently than other heat only boiler alternatives. 

Track Record

The boiler has only been on the market around 18 months, so there is no real track record to base these boilers on as of yet.  Everything we suggest is speculative. 

Our Thoughts On The Overall Design

Being brutally honest, we do not like the build-quality and believe it has some serious design flaws. The boiler is small and very quiet in its operation, but this is the only plus we would give it.  

Above is a picture from a Baxi EcoBlue Advanced that we serviced recently. The boiler is one years of age. The latest version incorporates a Socket & See test point which is not shown on this version.  

Firstly, the boiler built around an aluminium heat exchanger, which in our experience and opinion, is prone to issues. 

For more information about aluminium heat exchangers and why we do not recommend them, please click here.

The way the flow and return connections are made onto the heat exchanger could be prone to leaks where systems are not correctly flushed and treated with inhibitors during installation or other heating system works, which is a widespread occurrence.

More information about this type of heat exchanger connection can be found by clicking here and reading the first part of the article which gives details about this under the “Worcester Bosch” section. 

We expect common issues from the combustion control unit ( “A” in image below), which incorporates the boilers fan. Circuity for the fan is directly mounted to the main heat exchanger. The constant sharp rise and fall in temperatures in this area we believe will take its toll on the circuit board that is mounted here. Only time will tell, but we expect this part to require replacing more frequently than what typical fans on many other boilers would. Given this part costs around £290.00 online, which could even be higher from some local merchants, this is not going to be a cheap repair for the homeowner. 

The automatic air vent, in our opinion, is disgraceful!  As above (“B” in the image) which you will see the top right corner of the aluminium heat exchanger, which is black and cylinder shaped, is made from plastic! 

Given that this component is plastic, and that it is mounted directly to the main heat exchanger which is constantly heating and cooling when in use, if/when this component fails, especially where it splits and there is a large body of water above the boiler, such as radiators and self-filling header tanks, water could pour from this point. Not only could this destroy the boiler and cause extensive damage by soaking the combustion control unit and main PCB, but it could also cause a large amount of damage to the property. Again, due to the age of the boiler, we can only speculate here, but having that component made from that material, in that location is just asking for trouble in our opinion. If this were to happen, it could lead to it being more economical to replace the boiler. 

The font combustion case, as shown above, is made from plastic, with plastic securing clips and polystyrene used as an insulation material. How the polystyrene here and the rest of the case will fair over time we are unsure, there is a good chance it will be fine, but we certainly do not have high expectations for the clips on the case, as shown above, or possibly the case its self should the boiler ever suffer from the explosive ignition. In our opinion, as the plastic case becomes more brittle from heat and UV  exposure over the years, the clips could snap off when being worked on, resulting in a new case, being required. Again, an expensive repair. 

The drop-down panel which houses the main PCB also has plastic hinges and could be broken easily by mistake by service engineers. Although this is held up by screws and is non-essential, it’s still a poor way to go about things in our opinion. 

Just based on the design, we would expect these boilers to last in the 12-year range, mostly being replaced from becoming beyond economically viable to repair for the reasons specified, but again only time will tell. A big thumbs down to Baxi from us with this product!


We believe there are far better products on the market, such as the Vitodens 100W Open Vent, which we would expect to last far longer and with fewer repairs. Not only this, for similar costs you can get boilers with 10-year warranties.