Viessmann vitodens 200 wb2 11-44 boiler problems

bfriel64

hello all I am having a problem where the boiler starts ,lights up,and shuts down right away

This will happen a few times and then it will light

There are no codes but viessmann manual says this symptom is due to flue gas system leaking

I have cleaned out in between radial heat exchanger with tool and flushed thoroughly with water

There is not a glue gas smell

Any help would be appreciated

Thanks

Brett

109A_5

Fuel pressure ?

bfriel64

thank you I’ll check I have a manometer

Brett

bfriel64

follow up on my viessmann

Turned out to be the gas valve

Fortunately I bought a complete used boiler for $550 and had the spare part

Thanks for the help

Brett

109A_5

Thanks for the feedback. With changing the Gas Valve you may want to have it checked with a combustion analyzer.

bfriel64

probably a good idea before I changed gas valve I changed the lgm29 board thinking that was the problem the board works but I notice it more short cycles itself to reach boiler temp limits and dhw settings

With original board in it would crank out on max to reach these settings now it kinda short cycles its way to the settings

I may put original lgm29 back it to see if behaves as it use to

I rember that I did not Mach up dip switch settings on replacement board so maybe that’s the problem

But am super happy it’s working now

I like this older viessmann it appears to be well built

Brett

109A_5

The donor control board may have been configured differently (DIP Switches and electronically stored parameters).

bfriel64

yes I think you are right

GGross

this is the instlal sheet that would come with a replacement lgm29

https://www.viessmann-us.com/content/dam/public-brands/ca/pdfs/doc/wb2_rep/vitodens_200_lgm29.pdf/_jcr_content/renditions/original./vitodens_200_lgm29.pdf

I am pretty sure they still had an older form of what they call lambda pro today, on those boilers. so the gas valve is most likely non-adjustable. but you would want to make sure both units were set to the same fuel type. Also there is a water pressure sensor inside the unit which can shut it down if water pressure is too low.