Vaillant boiler status with honeywell controls

[Mariano]

Hi guys

I am replacing the vr350 control to my ecotec plus 630 with a honeywell evohome system as i need more zones etc.

However i will loose access to boiler technical data i guess like fault codes , sys pressure, flow temp etc.

Can i leave the vr350 hooked up to eBus purely for this purpose without affecting the commands from honeywell module?

Is there a better way to achieve what i want to do?

Thanks

 

[stem]

Does the boiler not have its own integral display for displaying the fault codes etc.?

Even if it doesn't, the Vaillant boilers I've seen have the possibility of adding a Remote Thermostat (RT) The wiring terminals provided are marked RT 230v (or RT 24v) with a wire link fitted between the two terminals that would be used. The vrt 350 will probably only be connected to the Bus + and - terminals.

If the Evohome is using a BDR91 receiver, then it has potential free contacts that can be used with either 24v or 230v.

Leaving the 350 in place would means setting it to be 'on' 24/7 so the Honeywell can take over control, which probably isn't really an ideal set up.

However, someone else may be able to suggest other options. For example, if the boiler doesn't have an integral display presently maybe Vaillant have a module that could be added so that the 350 could be removed.

 

[Mariano]

Indeed the inbuilt display is pretty basic and boiler is in loft which is hard to access.

Yes the idea is to hook up the evo to the RT and the vr350 to the ebus but not sure the system wilk get its knickers in a twist.

 

[GuessMan]

Yes it is possible to leave the VRT350 and VR65i n place.
You leave it set for continuous heating and at a room temperature of 30+ degrees. Make sure it is set to two step not analogue (modulating). The control knob should be set at 75.
The BDR is connected across 3 & 4 to switch heating.
The hot water temperature and preheat times are still controlled by the VRT350 and the control knob should be on max. And you don't need an Evohome hot water kit.