Programming option, Viessmann B2HA

JohnNY

I yet again find myself in the highly unfortunate position of having to commission two Viessmann Vitodens B2HA boilers and the display of ancient hieroglyphics they call a control. I need to run them without the outdoor sensors for a week or so while some other work is completed on the building but the boilers don't like to run without it and they go into alert which is not ideal.
If someone here knows how to program the boiler to ignore the missing outdoor sensor, I would thank you for passing that process along to me.

EBEBRATT-Ed

I don't know but

What if you found the resistance of the outdoor sensor at say 20 degrees outdoor air and buy a resistor and wire it in

Paul Pollets

You'll likely have to contact the Toronto (Waterloo) office to get the answer. 800-387-7373 ask for Jeff Cox

Alan (California Radiant) Forbes

The Viessmann Application Guide is very handy for setting operation parameters.

Click here, scroll down the list and highlight "Vitodens 200-W, B2HA" and then click on "Application Guide". Page 30 has the instructions you're looking for from the Setup Wizard.

JohnNY

Alan (California Radiant) Forbes said:

The Viessmann Application Guide is very handy for setting operation parameters.

Click here, scroll down the list and highlight "Vitodens 200-W, B2HA" and then click on "Application Guide". Page 30 has the instructions you're looking for from the Setup Wizard.

Interesting, Alan. Thank you.

JohnNY

EBEBRATT-Ed said:

I don't know but

What if you found the resistance of the outdoor sensor at say 20 degrees outdoor air and buy a resistor and wire it in

This is funny. I actually took two of the resistors that come with Taco relays now and put them in series to clear the missing sensor fault. It reads 147° but it worked to make DHW. Great minds think alike? Thanks for chiming in.

EBEBRATT-Ed

@JohnNY
I am far from a controls expert. But if a sensor is bad (or non existent) you can sometimes fool a system by disconnecting or jumping the sensor or in this case faking it out.

Probably somewhere in the Viessmann material it will have a chart for the sensor outdoor air versus resistance

mattmia2

EBEBRATT-Ed said:

@JohnNY
I am far from a controls expert. But if a sensor is bad (or non existent) you can sometimes fool a system by disconnecting or jumping the sensor or in this case faking it out.

Probably somewhere in the Viessmann material it will have a chart for the sensor outdoor air versus resistance

hopefully it will also go in to a default mode if it is shorted.

Of course you would hope that for it being open as well.

ratio

I just remembered about these in another thread. Maybe one of them would work, & allow you to complete the ODR as well?

EBEBRATT-Ed

@ratio
those sensors look like a lifesaver on some jobs. Hopefully they are dependable. Indoor range is 2000 feet.

Based on passed experience with Trane wireless sensors used as thermostats on a job 5 years ago I have my doubts. They would work in some buildings depending on wall construction and picking up "noise" from other building wiring but were not reliable in all cases. + the battery issue