Vaillant ecoFIT Sustain boiler query.

[Framing]

I have a Vaillant ecoFIT Sustain (system?), boiler, with hot water tank. We have hot water and radiators heat fine. My query is that only the radiator symbol on the boiler has been set (70 degrees), the ‘tap‘ symbol says ‘off’. I guess it’s the same temperature for both hot water and to heat radiators? Can I turn on the ‘tap’ symbol and give the hot (tap), water a separate temperature? Thanks in advance.

 

[gmartine]

Section 4.9....

https://www.vaillant.co.uk/downloads/aproducts/ecofit-sustain-2018/system-boilers/26-02-2/ecofit-sustain-system-operating-instructions-1672143.pdf

 

[Framing]

Thanks for the information. Yes, the display will let me change the setting from off to the desired temperature, but wondered why the 2 temperatures weren’t set in the first place. I’ve heard that depending on how the system was installed that even if you set the 2 temperatures independently, only one will work?

 

[gmartine]

Who knows, either talk to the installer or the previous owners. As you can now set both then I'd do so.

I don't think I'm missing anything but I can't think of why under what conditions the boiler would default to one setting if two were set but happy to be corrected.

 

[Ben-gee]

I suspect that your boiler is a combi - but being used as a system boiler.
i.e. the heating side (radiator symbol) is used in conjunction with motorised valve or valves, to heat the cylinder and the radiators.
The hot water side (tap symbol) may not be being used at all.
This is exactly the setup I have at home.
Reason - the combi version was a couple of hundred quid cheaper.
I could of course be completely wrong 😃

 

[Framing]

Yes, hot water tap symbol set to ‘off’. Just reduced temperature (radiator symbol), down to 60 degrees, hopefully a balance between safe hot water and hot enough for radiators. Everthing boils down to money…..

 

[Ben-gee]

The temperature of the water is controlled by the thermostat on the cylinder, not by the boiler.
With the proviso that the cylinder cannot get hotter than the boiler temperature.

 

[Framing]

The temperature of the water is controlled by the thermostat on the cylinder, not by the boiler.
With the proviso that the cylinder cannot get hotter than the boiler temperature.

I’ve had good look, but there doesn’t seem to be thermostat on the cylinder. Lots of wireless ‘gubbins’ in the airing cupboard, perhaps a part of that?