Gas Boiler Question

[chrisb2]

I have a Vaillant ECO Tech Plus 418 for my CH and HW and would like to know if the boiler setting should be set at maximum for CH or not, and if not which setting should I use on the boiler itself?
Many thanks.

 

[D_Hailsham]

Do you have a room thermostat?

 

[Agile]

I have a Vaillant ECO Tech Plus 418 for my CH and HW and would like to know if the boiler setting should be set at maximum for CH or not, and if not which setting should I use on the boiler itself?

Many thanks.

Unless you have an ( expensive ) Vaillant controller which alters the boiler flow temp automatically you need to set it taking the hot water into account.

To ensure adequate heat transfer into the hot water the boiler temp needs to be set 10 C higher. So if your HW is set at 55 C then the minimum boiler flow temp needs to be at 65 C.

In very cold weather the flow may need to be increased to 75 C or higher to get adequate heat out of the rads. But it can be turned down lower when its not so cold.

The flow temp should be as low as possible to encourage maximum boiler efficiency comensurate with heating the hot water correctly.

Tony

 

[chrisb2]

yes I do have a room thermostat for the CH but the boiler itself has two manual circular controls: one for the heating with a RAD symbol, and the other as a HW symbol control, the latter of which is in the OFF position and has never been switched ON. However, the HW is still heated via the gas boiler and set at 60C on the HW Cylinder thermostat. I am confused as to the ideal and most economical method of setting the controls. I think I understand your post Agile but is there any other way you could explain this for a rookie such as muself?

 

[Agile]

Perhaps someone else can try to explain it.

You need to set the boiler CH to at least 70 C while heating hot water.

The HW control on your model has no effect.

Tony