Viessman 100 Weather Compensating Sensor

[Gammy leg]

Hi
My 2017 Vitodens 100 is due a service and as part of it I want to get a weather compensation sensor fitted. I've checked in the installation book that it has the capability to have one connected and I'll leave the installation to the service engineer.

Just wanted to check whether this option from screwfix is all that is needed.

https://www.screwfix.com/p/viessman...X?tc=HC4#product_additional_details_container

Thanks

 

[desktop987456]

Just to be sure check out which one is yours; heat only or with DHW

Weather Compensation

Viessmann Vitodens Weather Compensation

viessmanndirect.co.uk

 

[Gammy leg]

Thanks for the link. Mine is the 100-W B1KC. It does heating & DHW. The price on the Viessman site is only a few quid more than Screwfix so may go direct.

 

[Jackrae]

Remember to install it on a non-sunny wall (ie North facing) If that's not possible then you'll need some form of sun shield to prevent the sun skewing the sensor's measurement.

 

[Gammy leg]

Conveniently the wall is north facing.

 

[desktop987456]

I am resurrecting an old post in hope that contributors of this post have WC working.

I am trying to install Weather compensation sensor on 100-w heat only boiler (2018 model; dial type with only 1 flow temperature for CH only).
I have connected the WC sensor as per instructions with the supplied cable.
I have drayton LP822 programmer and RTS thermostat which goes to (switched live) port on boiler 96 port to turn the boiler on/off.

Issue : The boiler switch on and display temperature and CH symbol but it won't ignite. It just stays there. When I disconnect the WC sensor from PCB (X21 port on Viessmann), it works fine in non WC mode.

Can anyone help to get WC working for my ststem.