how important is perfect placement of weather compensation sensor for a Viessman gas boiler?

[Adsibob]

So I've read all twelve articles on the forum that mention wc in the titles, and apart from a brief reference to putting it on a northern facing wall, in the shade, there wasn't much discussion of what impact a suboptimal placement would have on a gas system boiler.

 

I'm considering upgrading a badly designed Viessman Vitodens 200W System boiler setup and one of the things I'm considering is adding wc. Options for placement are as follows:

 

1. If performance is significantly enhanced by placing the sensor on a north facing wall, then the only north facing wall I have is the north side of my first floor rear extension. This is mostly in the shade, but will get some sunshine in summer, towards the end of the day, for a couple of hours. I think in winter it is completely in the shade, but will double check this weekend. 
2. I have is a south facing wall which is the alleyway down the detached side of my semi detached house. Because our house and the neighbouring house are fairly tall (about 10m each at the apex) and because the alleyway isn't too wide, my side is about 90cm wide and my neighbour's similar, so maybe 190cm with a fence between them, the alleyway will probably be in shade for two thirds of the day. But in summer, the middle third of the day could last for 6 hours or so, which could throw off things significantly.
3. That south facing wall is also where my wood burning stove's inlet pipe is. How about locating the sensor just inside the pipe, i.e. just the other side of the vent cover of the pipe. In that way it is in the shade, but might not draw air in when the stove isn't being used, so might be a problem. It might draw a lot more air in when the stove is being used, and not sure if wind chill can affect sensor readings. Maybe a bad idea.
4. That south facing wall also has a plastic white gas meter cabinet attached to it, which is significantly bigger than the gas meter. Could the sensor go in there, or would the plastic box heat up like a greenhouse in the sun? Could the sensor go underneath that white box?

 

Fun and games.

[JohnMo]

I would say, any sun is bad, when heating is expected to be on - who cares about summer sun your heating is off.

 

 

 

[marshian]

28 minutes ago, JohnMo said:

I would say, any sun is bad, when heating is expected to be on - who cares about summer sun your heating is off.

 

 

 

 

I think that is the perfect answer

 

Our house faces North - back of the house faces south - even in winter we get a little solar gain in the back rooms never ever seen solar gain on the front rooms but get a fair bit in the summer evenings

[Adsibob]

Okay, so north first floor wall it is. The next question then is do I have to run a wire from there to my boiler, or is there a wireless solution? My boiler is connected to the internet, so I would hope there is a battery powered wireless solution which can speak to it, although I guess that would be very annoying if there's an internet outage. Radio communication might be best.

[Lofty718]

My weather compensation sensor is badly placed on the black facia on NW facing wall so it heats up in the sun lol I've been meaning to grab a ladder and move it but it is not actually much of an issue at all, mainly because when there is any meaningful sun that can tamper with the sensor the heating is off anyway

 

Mines wireless I imagine Viessmann have a wireless version too