Combi boiler swap & upgrade

[eatontrifles]

For a number of reasons our combi boiler needs replacing, so I'm looking for suitable replacements and would appreciate some input. It needs to meet the following spec;

• Needs to be compact enough to fit in the existing space (under stairs outdoor cupboard) so similar to the existing 395x700x285 (WxHxD). There is around 120mm of clearance to one side for a slightly wider unit, but not much top & bottom due to sloping ceiling and existing pipes.
• Compatible with modulating demand, I have a Tado system which supports various protocols.
• DHW flow rate of 13l/m or better.
• Suitable heating capacity for seven radiators in a 1930's semi (for reference the current boiler is a 24kW and copes fine for heating).
• Budget around £1100.

We have very good cold water pressure and all rads are less than 5 years old.

I've been looking at;
Intergas, specifically HRE 36/30 and Eco RF 36 models which will meet the above and are under budget, although they need an external expansion vessel. 10 year warranty.
Worcester Greenstar 36CDi compact and 32CDi compact meet spec but are both more than budget. Five year warranty.
Baxi 636 which has a huge DHW flow rate of 15 l/m and a seven year warranty but I'm unsure about the brand/reliability.
Vaillant EcoFit pure 835 mets spec, is just over budget and 7 year warranty.

Any others I should be looking at or thoughts on the above? I'm erring towards the Intergas currently due to the warranty and seemingly sensible design - I have space for the external expansion vessel. The Baxi is tempting with the hot water performance, and stainless steel heat exchanger.

 

[Dan Robinson]

Stick with the Eco RF A decent engineer will find a space for the expansion vessel.

Or maybe the Xclusive.

 

[eatontrifles]

Just had a look at the Xclusive and it's too big for the space. In looking though, I'm not sure if an Eco RF 36 is also too big - the Intergas website lists the height as 710mm (which is fine, and is the same as a HRE) but there is a page in the manual which says it is 840mm, although earlier listed at 710mm. Need to speak to Intergas to find out which is correct.

 

[Dan Robinson]

RF 36 is 840 including pipes.

RF 30 is 780.

Xclusive 30 is 766

 

[eatontrifles]

Ah yeah, just spotted that the picture is measuring the pipes as well. So the boiler size of an RF 36 is still 710mm?

 

[eatontrifles]

Any additional input from the weekday crew?