Expected Life of 22 Year Old Viessmann Vitodens 200

whats the error code?

hm weird thing is the boilers that have those faults aren't quite 22 years old. the models I would expect at that age use different faults. I wouldn't worry too much about viessmann disappearing for a good while longer they still offer parts for their first wall mounted boilers. your 2 fault codes are for fixed high limit (f2) and no flame (f4) the F4 is what i tend to call the lack of maintenance error code, burner needs a whole service, full cleaning of the fire side of the heat exchanger, condensate flush, new electrodes probably, visual check everything. the F2 can be related but is usually due to air or flow issues like your contractor said.

You are right they will not 1 to 1 drop in but depending on what kind of vent pipe you have, and what if any viessmann accessories you have it might fit back in easiest. if you don't have a viessmann branded mixing valve you could replace with a 100 series save some bucks. honestly though if your tech is pretty good those 2 errors are mostly just service related not parts. that being said it's a good idea to look at a new boiler after 20+ years in my opinion.

In my area we have lots of those attached to air handlers.

yeah the errors you gave (when I read them correctly) are for the older unit i suspected. That A4 is a weird code i've never seen. it thinks there is a variable speed heating circuit pump attached to the boiler (not boiler pump) and its not communicating so its running it to max speed. A4 won't be a lockout error. 02 is still FHL so like the tech did, look at air, flowrate etc. Controls, pump, fan are getting pretty pricey on those but they are all still available. we still stock all of the parts for that series at my shop but I have been cutting back a little since they becoming less common.

Whoever replaces it just make sure they dont assume they can reuse the outdoor sensor and DHW sensor. I cant remember exactly which model did this but one of the older ones used a different resistance sensor than everyone else did. most boilers now will come with their own DHW and ODR sensors so no big deal. If you have coax venting (pipe-in-a-pipe usually looks like a single white metal pipe) you may need an adapter to 2 pipe, some of the sizes were oddball in that era, most still just fit right to a new viessmann though.