Alpha CD50 or Vaillant 937

[RedEric]

Which Storage combi-boiler performs best (flow rate, duration, ETC)
I've narrowed it down to these 2 (but still open to suggestions).
I need a combi because I have no space for a HW cylinder but I need enough HW for a 4 bed house with 2 bathrooms.

does anyone have experience with either (or both) of these boilers?

 

[Deleted member 105431]

Vaillant is in another league to the alpha

 

[RedEric]

It's almost impossible to compare the stats from the websites.

The Vaillant offers 15.2 l/m @ 65°, the Alpha offers 18 l/m @ 55°. Which is better? I presume this is the blended flow rate, so what's the flow rate when the storage is depleted?

The Alpha has 52 litres HW storage whereas the Vaillant only has 15 litres of HW storage. Surely the Alpha can offer a decent flow rate for longer?

Has anyone installed an Alpha CD 50?

What are your reasons for the Vaillant?

 

[simond]

Just have a look inside the CD50 if you are in any doubt, a picture is on their website. Spot all the insulation to retain the heat and noise. The neat wiring centre protected from leaks.

It's all very well comparing flowrates, if you want something tasty get the ACV Heatmaster, that'll do 41 litres per minute for a while.

But have you got the water supply to cope?

 

[gas4you]

If you want real reliability, build quality, good flow rate and a boiler that is not a cheap version made for the UK market, look no further than the ATAG Q series combi's.

 

[Deleted member 105431]

Have a look at the glow worm Xtramax HE and also the glow worm ultrapower sxi. I personally prefer the 937.

 

[RedEric]

Have a look at the glow worm Xtramax HE and also the glow worm ultrapower sxi. I personally prefer the 937.

As the Glow Worm boilers have much larger HW storage than the 937, doesn't this mean that they are more capable of supplying large amounts of HW?

 

[Deleted member 105431]

yes but the vaillant is better made.

 

[Paul Barker]

When I was fixing Alphas CD50 were ultra reliable. The flow switch was bullet proof on this model, it used a very reliable wax stat which never needed changing. All modern Alpha sport a single pcb design which is faultless, I never changed a cd50 pcb.

The only faults I ever had on a cd50 were one fan (flamingo land staff quaters with a cd50 going full steam 24/7/365) which was basically the equivalenmt of 10 years old in usage. and new excpanshion vessel.

There was a brief period 18 months ago when they had a recall on mounting bracket that is all over.

You cannot choose a more reliable boiler.