Worcester Greenstar 25i Erp Review

The Worcester Greenstar 25i boiler is basically just an upgraded Greenstar Junior, which is probably one of the most popular boilers in the UK over the past decade, and now the 25i is also one of the most popular boilers in recent years. It has always puzzled me as to why these 2 boilers are so popular, as I spend most of my time fixing them, I personally think the junior had a lot of design flaws, and the quality and materials of the components were a bad choice, the 25i has huge improvements over the junior, but worcester missed a huge opportunity to design a great boiler. 

It's an ErP Compliant, Condensing Combi Boiler. Unfortunately the Greenstar i model is only available in combi outputs of 25kW and 30kW. It's suitable for small to medium sized properties with one bathroom. 

The Greenstar i includes a pre-assembled wall frame with mounting hooks, this fits directly over the old junior and Si wall frames. It has the same dimensions as the Greenstar Si and Junior, making like for like replacements very simple. 

All the components within the boiler are serviceable from the front, and there is no need to dismount the boiler from the wall to service its expansion vessel as its now inside and accessible, and also the connection pipe is now copper, this is a huge improvement. Also no need to break the combustion chamber seal now to access the fan to check the bearing plate. But the PRV is still at the back and is not straight forward to change like it is on other manufacturers boilers, this is very disappointing from worcester as most engineers complained about the juniors prv for years and worcester clearly decided to ignore us when designing the greenstar i range. 

Service of the burner, baffles and heat exchanger still requires access to the hatch on the top right of the boiler, so consideration needs to be made on installation, I personally hate it when the flue is taken horizontally to the right and access to the hatch for cleaning is restricted, I much prefer forward facing radial burners instead of these down facing radial burners. 

A digital menu within the boiler control software also helps simplify completion of the Benchmark logbook. 

The i range contains a larger condensate syphon to tackle the issue of frozen condensate. 

The boiler’s Heatronic control panel has an all-improved interface, with text descriptions and error codes enabling homeowners to communicate their needs more effectively. 

Wall mounting jig providing pre-plumbing, and the ability to still run the pipes behind vertically is a much needed option, a pre formed pipe kit is available for this. 

 Rear piping as standard. 

 Lift weight of 31.7kg, which isn't too bad as boilers go. 

 Single sided front case for easy access, only requires 2 screws to be removed, no dodgy plastic clips that will break like on the Si compact. And no awkward angled screws like on the junior. 

 Pre-wired mains cable. 

 The digital communication protocol is EMS-Bus, but unfortunately it is not Opentherm compatible, this is something the industry are adopting on mass, yet worcester choose to ignore what the installers and customers are really asking for. 

Plug & play accessories are available, including optional facia mounted controls and weather sensor. 

Simple boiler controls with clear information display and one button commissioning mode. Benchmark menu in boiler On-board operational information and diagnostics. 

CondenseSure style syphon inside - risk of condensate pipe freezing eliminated. 

7 year warranty as standard, but 8 years if fitted with a Worcester system filter. 

10.2 ltr/min domestic hot water flow rate. 

Nox class 5 Erp A rated 93% 

Central heating can modulate between 7.14kW and 24kW 

Maximum standard horizontal flue length of 4.6M 

Aluminium Kebab style heat exchanger like in the Junior, Si and Ri boilers. 

710mm high x 400mm wide x 330mm deep 

In my personal opinion, the Worcester Greenstar i range is by far the better boiler in the current worcester line up, much better than the Compacts, and even better than the 2000, even though it cost more than the 2000. 

If you have a standard size 3 bedroom house with one bathroom, then the i range will be able to handle it, they have good flow rates and warranties, you can most probably get away with 30kW in most small to medium houses. 

If you fit 3rd party controls like nest or Hive, then you you'd only get 8 years warranty on the cdi compact where you would need to fit worcester controls to get the 10 year warranty. So there really is no point choosing the cdi over the I or si, the i range may be a little big, but surely most people can relocate the boiler to the loft, airing cupboard or storeroom etc. On price to performance the 25i and 30i come out on top of the Worcester pile, but I'd personally still prefer to fit Vaillant over a Worcester any day of the year, and I personally can't see why people would opt for a worcester over a Vaillant, I suppose its because Worcester have a very very good marketing team and a visible service team to back up the warranty calls.