Vaillant d.0

4 Dec 2018
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United Kingdom
Hello, having a bit of a 'mare with this one, so though I would seek out some help.

I have a Vaillant ecotech pure installed recently (the version that fits in a cupboard) around 24kw I think.

It seems to be using a huge amount of energy but never quite getting the rooms warm. I'm looking into the general insulation of the flat (being top floor has its drawbacks) but wondered about the d.0 rating?

I asked a local plumber who advise me to find the BTU for the flat (which a website online said was about 15,000-17,000 for a 2 bed flat. The to phone Vaillant who could recommend the right setting.

Sadly they only give that information to installers. so thought I would see if anyone had any suggestions?

Or should I just leave it on the factory settings? maybe it just eats gas?!?
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d0 is the max KW output of the boiler and should be set to the heat loss of the house. The boiler will modulate down automatically, though, so if the radiators are not getting warm, then you may have a circulation problem and the boiler may be shutting down prematurely.

I'd observe the boiler to see if this is happening and then adjusting d0 downwards to see if this helps. If it is set too low, the boiler will not be outputting enough heat to overcome the losses in the house on the coldest winter morning.

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