Viessmann Vitodens 100 26KW or Vaillant ecoTEC plus 831

simpleguy_blr

Hi

I have decided to replace my existing Conventional Boiler (with a tank) to a combi, the quote is £50 extra for a Vaillant combi boiler,

Property is a terraced two bed with one bath.

The independent gas engineer is trained by Viessmann but is happy to install the Vaillant.
Viessmann can be extended for a 10 year warranty by paying £200 otherwise both come with a 5 year warranty?

He recommends the Viessmann, How is the Viessmann Vitodens 100 26KW boiler compared to the Vaillant? Is it better to stay with Vaillant?

Please suggest

Thanks

simpleguy_blr

Any one using the Viessmann Vitodens 100 26KW? any know issues with this model?

Some of the online recommendations are to go with the Viessmann 200 but I understand that is for bigger properties from the gas engineer.

Or would the "Vaillant ecoTEC plus 831" be a better boiler? :question:

Cheers

Robwiz

I've no first hand experience of Viesmann boilers but I did search online for info on them. The big difference between the 100 and 200 is that you can have weather compensation on the 200.

That's worth having as it modulates the flow temperature to match the outside temperature so keeps your inside temperatures more stable. The manufacturer claims that weather compensation gives a gas saving of about 15%, which is probably worth having.

Other discussions I've read suggest that the 100 model was cost-engineered down to a price for the UK market. In mainland Europe the 200 is the bottom of the range. That's just online rumour. Have you searched online yourself?

simpleguy_blr

Robwiz, thanks for taking time to reply to my query.

Yes I did search online and what you have summarised in your reply is as much as I could gather, Did not want to install a Viesmann and later regret hence was looking for some opinions from someone who has used them or experts from this forum who can give some guidance.

The Engineer mentioned that 200 series is too big from my property of 2 bed rooms and a bath, consisting of 5 rads in all.

Robwiz

I don't understand your engineer's comment. The Vitodens 100 range is from 26 to 35 kW (combi) or 19-35 kW (system) with a modulation range of 1:4.

The 200 range is shown as having a rated output of 3.2 kW to 35 kW with a modulation range of 1:6. My understanding of combis is that higher output is good because they deliver plenty of hot water on demand. With weather compensation, the boiler would be running modulated except in arctic weather.

I've just checked the spec on the Viessmann website and they produce the same sizes in 100 and 200 series ranges, and as I thought, the 200 modulates down to a lower output.

J_B

We bought a Vailant Ecotec in 2009 and were swayed by 'reliability'.
There was only a 12 month warranty then.
Last summer it sprang a leak and had to have a new 'valve chest' (?) which cost nearly £200

:mad:

nickcc

We bought the Viessmann 100w 35watt combi boiler a couple of years ago, best boiler we've owned to date and cut the gas usage by 1/3rd from previous 10 year old Ideal combi. Only problem we still have is trying to set the wireless room stat, even the installer hadn't a clue, so we,re still using it on manual (perhaps I'm just thick).

sk240

It looks like you have been specced a boiler thats too big anyway, i wouldnt have thought you needed any more than a 24kw unit (like the vaillant 824) unless you have a really high water flow rate (over 12l/min)

simpleguy_blr

nickcc good to know that you have the Viessmann 100w and happy with it!

The engineer commented that Viessmann 26 should be fine for my property the Vailant Ecotec is too big as its 31 kw

Thank you all for your replies and inputs.