Vaillant System Question

[atkinsong]

I have a Vaillant system comprising Ecotec System Boiler, Unistor unvented system, and VR 65 control unit with NTC connection to the cylinder.
By default the boiler is set to give priority to hot water requests (thus closing the CH valve) but this can be changed to allow both heating and hot water at the same time, which I would prefer. Are there any drawbacks to this.
many Thanks

Geoff Atkinson

 

[gas4you]

From the VR65 instructions

If a parallel operation for central heating and charging of
the DHW cylinder is required, change this setting on the
boiler in the following way.
• Press the “i” and “+” keys simultaneously.
The display shows “d.00”.
• Use the “+” or “-” keys to scroll to the diagnostic
number d.97 to enter the second diagnostic level.
• Press the “i” key.
The display shows the relevant diagnostic information.
• Use the “+” or “-” keys to change the value (display
flashes) to 17 (password).
• Save the new value by pressing and holding down the
“i” key for approx. 5 seconds until the display no longer
flashes.
• Use the ‚+‘ and ‚-‘ keys to scroll to the diagnostic point
d.70
• Press the “i” key.
Change the setting using the ‚+‘ and ‚-‘ keys.
• Save the new value by holding down the “i” key for
approx. 5 seconds until the display no longer flashes

You need to set it to 1

 

[atkinsong]

Thanks for the reply Dave, but I think you have misunderstood my question. I know how to change it, I'm trying to decide if I should. I need to know the pros and cons of each option. Thanks.

Geoff

 

[simond]

If you have a weather compensated system solution (you do not list the controller) there will be a loss of efficiency by allowing the CH and HW to work at the same time.

Otherwise it is up to you. Be brave, try it.

 

[atkinsong]

Thanks for that Simon. I've got no problem with trying it; just trying to understand what circumstances suit water priority and what circumstances suit parallel.

Geoff Atkinson

 

[gas4you]

Silly me Sorry!