How to select a decent brand of boiler?

[mrmanchester]

We're installing a new combi condensing boiler as part of a whole kitchen/plumbing overhaul. We've decided that something around a 32kW would be about right (dormer bungalow - 5 bed, 2 bath)

Our installer recommended Baxi Main ECO 30kW - cheap but I'm not keen on this based on reviews
We suggested Vaillant Ecotec exclusive 832 or Worcester Greenstar 37Cdi look ok on reviews and are about same price as each other.
We're now being recommended a Viessman 30kW. Reviews on here and elsewhere aren't great.

So any thoughts on these boilers would be good - reliability and decent rate of hot water supply are key factors. Heat supply needs to be pretty good as the insulation in the dormer parts of the bungalow aren't great and are difficult to improve:

Baxi Main ECO 30kW
Vaillant Ecotec exclusive 832
Worcester Greenstar 37Cdi
Viessman 30kW

Thanks!

 

[Agile]

All makers think their boilers are decent!

You need to learn that any combi boiler will only give about 11 litres per minute of hot water.

Thats means that they cannot run more than just ONE decent shower at a time! Thats basic physics!

Any competent installer should have explained that to you!

Tony

 

[linkyplumb]

More important than the brand of boiler, is the quality of install.
I have seen a few dirt cheap aristons installed that have been really well installed, and many wb or vaillants that have been installed terribly.

What are your incoming cold main flow rates?
IMHO, a 32 kw combi will not be enough to service 2 bathrooms at the same time.

Maybe look at an unvented hot water cylinder, if you have the flow rate and the space. If space is limited, then look at Glowworm ultracom2 35 store. Basically a combi bolted on to a pre heated store.

We need to know flow rates

 

[Dan Robinson]

5 bed 2 bath - combi boiler = bad advise unless the limitations have been explained.


32kW for heating seems high to me, and your hot water needs may exceed the combi's.

 

[gavinda]

Iirc on the Worcester website, they suggest that their combi's are suitable for that size property, providing the mains is up to it. I have a greenstar 35 cdi in mine and detect minimal pressure loss when multiple hot water demands are on. I have a 22mm cold mains right up to the last meter and it barely registers when I'm in the shower and someone turns on another tap.

I have not measured the pressure though, purely working on the 'jump' reaction

 

[mrmanchester]

I'm not expecting to be able to run 2 showers at a time on a combi (or even a fast tap and a shower!) but just wanted to give an idea of the size of house. When I use the 'boiler calculators' for our house size it recommended 40/42kW boilers which just seems like massive overkill when our current, old 30kW boiler isn't far off the mark.

Our current Ideal ISAR 30kW combi boiler is doing an ok job and if we weren't completely stripping out the room that it is in we may have left it another winter before changing it, so happy to stick with a combi but one that's a little more efficient, condensing and reliable. I'm guessing our installer is registered with Baxi and Viessmann hence the recommendations.

 

[linkyplumb]

Ok Then
As you have a 30kw at the moment, and realise its capabilities, then go for A vaillant 831. Good boilers. Personally the exclusive is not worth the extra cash.

 

[doitall]

If your installer is Viessmann approved then go with them, certainly better than most.

Now if your installer was Atmos/Intergas approved it would be no contest.

 

[JohnD]

Fill a bucket at the kitchen cold tap, time it, see how many litres per minute you get, and report back please.

 

[mrmanchester]

Thanks, I'll try that - I think it'll be pretty good as the mains is more powerful than I've had in previous houses but we'll see.....

 

[Agile]

Or is a few words, many 2thinking@ installers favour Viessmann or intergas ( Atmos ) boiler.

These have a five year warrantee when fitted by an approved installer!

Tony

 

[Agile]

Or is a few words, many "thinking" installers favour Viessmann or intergas ( Atmos ) boiler.

These have a five year warrantee when fitted by an approved installer!

Tony

 

[holty]

what has'nt been mentioned is which viessmann. there's a new 111w range that gives out around 17 lpm 30kw or 20lpm 35kw. viessmann is an excellent boiler and virtually all i install besides glowworm. most peoples bad experience with viessmann was the old wb1a range. a boiler made just for the uk. there all now german made for the european market .

 

[mrmanchester]

I reckon the cold water flow rate is approx 10 litres per minute

 

[simond]

The 1XX series are not sold in Germany.

With 10 l/m you dont need a combi boiler >31kw