Controlling Vailant boiler CH and DWH temps independently

[Detailme]

Hi ​to all, found the forum on my quest to better my current heating system. Seems the most knowledgable forum so a good start.

Ok So my house is a 1970's 4 bed detached, upgraded cavity wall and loft and new double glazing. The system consists of a valiant Ecotec pro 630 system boiler, unvented cylinder, traditional rads with trv4's and single garage conversion and small porch running single zone ufh. I have three of the new heatmiser smartstat running as upstairs, downstairs and garage conversion. An old Drayton time clock operates the DHW.

I am aware that the boiler output itself is overpowered for the house but that's not the end of the world as I can tweek it's output to a lower kW.

What I would like to know is what can I add (in the way of valiant controls? Or 3rd party?) to my system that enables me independently control water output temperatures for the CH and DHW? In the Boiler engineering menu's there is function to set temp output for CH and DHW and further DHW settings but the DWH parts are all non adjustable. Im just really after having a lower CH output (say 55c) to DWH (65c)

To get the boiler return temp and thus get it condensing around the 53c mark and for a comfortable radiator temp would require around 50-55c output yes I want over 60c for anti legionella. Also a lower Temp for the UFH would limit the cycling somewhat!


my original thread has been closed and I can't thank or reply so have started it again, sorry if this is wrong?!

Chrie

 

[Chalked]

As my other post.
Vaillant do a controller for this and a bus connector that goes into the boiler circuit board to control temps.
Total cost of materials would be about £450. You will never get a return on that.
plis it's the worst thing in the world to set up!

Or you could install a weather compensated circuit with a mixing valve and seperate pump.
Thus works well on commercial systems, but won't save the install cost on a 4 bed house. Bearing in mind on a morning if your heating is on for a couple of hours, your heating the water most of that time.

 

[Chalked]

Or just Run the boiler at 65 ?

 

[Unregistered]

Thanks for your input. I just can't figure out why Vailant don't allow such a simple request like separate DHW and CH inputs from say a thermostat (simply wire the stat into the correct circuit). You could set which one would prioritise over the others.