New set-up advice: Unvented cylinders, boilers, softeners...

[travisbickle]

Hi all. Please excuse this novice. I've been searching these forums for advice on new cylinders but am still nonethewiser!

We are currently having a side return extension built onto our terraced house in London. The extension will incorporate a bigger kitchen, new cloakroom and downstairs wetroom.

So we plan on installing a new system boiler together with an unvented cylinder. We've pretty much settled on the Valliant Eco PLUS 630 as our boiler but are having trouble choosing a cylinder to go with it.

Part of the work taking place will involve changing the mains pipe to 32mm. The property, once the extension is complete will have two shower rooms, one bathroom and a cloakroom together with a kitchen which will house two sinks. There are four bedrooms and five people will be living in it. 16 radiators in all and underfloor heating in 3 rooms.

I've read good things about OSO but I'm not sure exactly what makes them so good. The temptation is to go with Heatrae but we really don't want to pay over the odds if we're not getting something better quality. Then there's obviously the route of going with the same brand as the boiler: Vaillant.

Also I'm still confused about the size we need. I keep getting conflicting information from various plumbers. Will 250l suffice? Should we future proof with 300l instead? Won't it cost more to heat fully?

Running costs and energy efficiency are of utmost important to us.

We also want to to install a softener and TRV system like Evohome but I'm not sure which equipment would work best with our set-up.

Please help!

Thanks in advance.

 

[Agile]

I always advise 50 li plus 50 li per person so that would give you a 300 litre for five people.

Once you have heated the cylinder the first time you only heat what is used.

They are very well insulated and only cost about 20 p a day to keep warm.

I always prefer the types with a separate expansion vessel and find the Santon to be good value.

Tony

 

[oldbuffer]

If you are going with Vaillant for the boiler, then consider what controls you are going to have. If you opt for weather compensation and VFR470 / VR65, then using the Vaillant un-vented cylinder give you more options for heating / hot water control as it allows the use of the Vaillant (supplied) thermostat for the cylinder.

 

[dcawkwell]

Glow worm ultra power. Gas boiler and unvented cylinder in the one nice box and will outperform a 300 litre unvented cylinder.
Immersion heater backup and falls back to combi mode should the water run out. It is the biz.

 

[Dan Robinson]

Flirking nora, do you have that as a a cut and paste?



"Hi people I have a drippy tap."

" Fit an ultra ultra power"

 

[Agile]

I think that's the second time today!

Only surpassed by those who recommend weather compensation!

And in history by Dr Drivel and his thermal stores!

Tony

 

[dcawkwell]

Flirking nora, do you have that as a a cut and paste?



"Hi people I have a drippy tap."

" Fit an ultra ultra power"

I can't help it. It's the right answer. If someone mentions unvented cylinder.
It's ultra power job done.

 

[Agile]

Dr Drivel used to respond to unvented cylinders with his thermal store rubbish!

 

[Dan Robinson]

Flirking nora, do you have that as a a cut and paste?



"Hi people I have a drippy tap."

" Fit an ultra ultra power"

I can't help it. It's the right answer. If someone mentions unvented cylinder.
It's ultra power job done.

Not in the places I am am working in at the moment.

 

[travisbickle]

So can a softener be installed into this setup without any problems?

I'm really keen on installing Evohome and the TRVs. With a Vaillant boiler, does that makes sense?

No one recommending the OSO I see. What are the advantages of having a separate expansion vessel?

 

[travisbickle]

Oh and excuse my ignorance by does the Glow-worm incorporate a combination boiler? I thought they generally weren't recommended for larger properties?

Any other suggestions for an unvented cylinder?

Finally, I realise this might be a stupid question but is a larger cylinder generally more energy inefficient and costlier to run than a smaller one?

 

[travisbickle]

So we ended up going with a Vaillant 630 coupled with a Unistor 630.

I plan on getting the new fandangled Evohome system when it is released next year but my question is do we still need the Vaillant controls such as the VR65 and what not?