Bolier replacement - Which on?

[rich42]

I am looking to replace my 25y old gloworm vented system bolier with a combi.

Looking for pluses and minuses for the following choices:

ATAG IC Economiser 27 Plus
Viessmann Vitodens 050-w
Ideal Logic Max 30Kw
(have i missed any?)

The house is a 3 bed semi, one bathroom.

Reliability is an important factor.

Your comments are most welcome.

Rich

 

[vulcancontinental]

You have missed Baxi, Vaillant, Worcester, Intergas, Vokera, Ariston, Alpha, Glow-Worm, Main and probably several more.

Plus and minuses on those boilers requires an essay as it would on all the ones I've mentioned above.

Keeping it short, Atag: 180 welds on the cross tubes and a couple of meters of thin rubber gasket in the headers of the heat exchanger. Efficient. Long warranty. No spares or support available for a gas service engineer, only sold to approved installers under contract. A franchise. Good weather compensation and OpenTherm an option. Very niche sold on exclusivity.
Viessmann: Expensive spares sometimes on long delivery, large bore heat exchanger but with restrictive elbows, I think the rubber hoses have been discontinued but often blocked plates are mentioned in posts. Reasonable priced model but lower spec than others in the range. Good weather compensation and OpenTherm an option. A bit niche depending on your area.
Ideal: Poor modulation, not sure it can even be range rated, large ali heat exchanger (something big and heavy to heat up then cool down in addition to running a bowl of hot water in the summer). Good support, lots of installers know the boilers, average weather compensation option but OpenTherm available. Not niche at all, very common brand.

There is no perfect boiler; the most important factor as always is a good installer especially as you are installing in an older system.

Look for good modulation, range rated, simple low mass two pass heat exchanger, no rubber hoses, no small bore in the exchanger, maximum 60 degree C on DHW supply, graduated start operation on heating, established company and readily available spares, at least 5 years warranty, and no additional payments if longer is a requirement.

I'm sure others will have differing views.

 

[stem]

Personally, for reliability I would skip the combi, especially as you already have a hot water cylinder in place. Combi's are more complicated than heat only boilers. For example, problems with their diverter valves seem to crop up very frequently on this forum.

Combi's also generally have many of the heating system control components internally, so any failure tends to mean specialised boiler parts that are only available from the manufacturer and a gas safe engineer to come and fit them. On the other hand, boilers with, external motorised valves, pump, cylinder thermostat etc., can be quickly fixed DIY or by local plumber using parts immediately available from any plumbers merchant or DIY shed. Great when something packs up at 2pm on a Sunday.

 

[muggles]

Look at...
Intergas Xclusive
Vokera Unica Max
Alpha Etec Plus

I wouldn't particularly want any of the ones you've listed

 

[vulcancontinental]

In addition to thanking muggles for mentioning the Vokera Unica Max I should say to the OP I work for Vokera so you know of my partisanship.

 

[Swwils]

What size boiler do you need?

Absolutely would not go for combi if you have the space.

Alpha or Veissman. But both need to be installed and setup by someone that is competent and will get you the right boiler to save you running costs.