Vaillant ecoTEC settings for use with vSmart and VR66 wiring centre?

[Matthew Butt]

We have a new Vaillant ecoTEC 624 boiler (installed in November), operating as a system boiler. It wasn't getting on well with our Honeywell thermostat, so we decided to get the vSmart thermostat and VR66 wiring control centre, which should work better with it.
One thing that seems to be missing from the installation instructions is the settings we need on the boiler once the VR66 and vSmart are up and running.
Should we set the boiler to the default settings or something specific? Or are the boiler's internal settings simply overridden by the VR66? It would be really useful to know.
Thanks!

 

[ShaunCorbs]

Wasn’t it set up when the vr was installed?

@king of pipes

 

[Matthew Butt]

The (Vaillant-approved) installer hadn't installed a VR66 before, and had been unable to find the information anywhere. He just reset the boiler to its defaults. We've actually had a Vaillant engineer out too, as the first VR66 was faulty (high-pitched noise like a cat deterrent, and not operating the valves correctly). He didn't have a clue about the boiler settings either. It's strange that Vaillant's own people don't have access to this kind of information either.
We've got the Vaillant engineer back tomorrow with the replacement VR66, so we'll ask again. I just hoped I'd get some info before he came in case he needs to get into the installer area of the boiler software where I can't go.

 

[ShaunCorbs]

I would say it needs to be set up but not 100% as I don’t fit that many king does so tagged him in

 

[king of pipes]

Your valliant engineer should be trained in these controls they can be tricky to configure

 

[Matthew Butt]

Your valliant engineer should be trained in these controls they can be tricky to configure

View attachment 36513

You'd think so, but apparently not. I think he might be able to phone their tech support people for instructions. Fingers crossed, and thanks.

 

[Matthew Butt]

Your valliant engineer should be trained in these controls they can be tricky to configure

View attachment 36513

Thanks, by the way, for the wiring diagram. It's the same as the one in the installer's manual. Interestingly, our installer contacted the Vaillant installer support team to check a couple of things, and they said the eBus connections should be combined at the boiler, not at the VR66 as shown in the diagram.

 

[Matthew Butt]

I've just had a reply from Vaillant technical:

"Both hot water and heating settings on the boiler should be set to maximum, as the vSMART is a weather compensator it will aotomatically adjust the boiler target flow temperature depending on the outside temperature."

I feel I've got somewhere, and it backs up what ShaunCorbs thought. Thanks for the input to both of you.

 

[fezster]

The vSmart thermostat uses ebus commands to control the flow temperature on the boiler, though you can limit the max flow temperature by adjusting the "radiator" dial on the front.

As Vaillant have said, your weather compensating thermostat will control the flow temp for heating. For the HW cylinder - it will force the boiler to 80 degrees during the HW cycle.

There is still some setup required to get the weather compensation working correctly, as there are a number of curves to select from depending on your home's profile.

 

[Matthew Butt]

There is still some setup required to get the weather compensation working correctly, as there are a number of curves to select from depending on your home's profile.

Thanks fezster.
How do we determine our home's profile for curve selection? Is it just a matter of what kind of heating, i.e. radiators? I notice in the Advanced Settings section of the vSmart app it's set our heating curve to 2.6 automatically.
Our vSmart is still in its "learning" phase for heating prediction.

 

[fezster]

I've no personal experience of weather compensation, but my understanding is that you let it learn the profile, and then adjust it by a notch or two if you find that a) the house is not heating up quickly enough, or b) it's unable to get to temperature on the coldest days.

 

[Matthew Butt]

I've no personal experience of weather compensation, but my understanding is that you let it learn the profile, and then adjust it by a notch or two if you find that a) the house is not heating up quickly enough, or b) it's unable to get to temperature on the coldest days.

OK. That makes sense.

 

[Matthew Butt]

An update...
We've now had our system up and running for a week (i.e. halfway through the 2-week "learning period". We had a message via the app last weekend to tell us it had switched to the advanced algorithm. The automatically set heating curve has dropped from 2.6 to 0.9, which probably sounds about right for a well-insulated modern house.
The temperatures are still a bit up-and-down, (ranging from 17.9 to 18.3 with setpoint at 18), but that's not too bad, and we're hoping it will settled down further. We're just a bit surprised that the boiler tends to ramp up to a flow temperature of over 60 (even with hot water switched off), when we thought it was supposed to run more continually and keep the flow temperature lower for the heating operation.
As you and Vaillant suggested, we've got the flow temperatures set to the max value in the default range, hoping the system can work out what it actually needs.

 

[John Mathews]

My previous experience with my ecotec plus 831 is that if/when it loses connection with the thermostat (which it did about four times per year) the boiler will continue running until it's internal flow thermostat setting is reached. As the manual advises you to set this to maximum, my house reached 30 degrees while I was on holiday in the middle of February. So any saving from having a modern thermostat were quickly lost. I am of the understanding that even with my new vsmart thermostat, the boiler will still default to the same situation. Hopefully the Vsmart will not disconnect as often as the previous model that I have replaced.

 

[doitmyself]

The temperatures are still a bit up-and-down, (ranging from 17.9 to 18.3 with setpoint at 18), but that's not too bad, and we're hoping it will settled down further.

That could be because the vSmart does not get its outside temperature information from a sensor on the outside wall of your house but over the internet from a 'local' weather station, which could be miles from where you live and not representative of your local micro-climate.