pybyr said:
I am glad to hear that at least this lambda boiler has a "limp" mode in case the sensor goes out, so that one is not dead in the water.
My one remaining hesitation (other than that I can't be boiler shopping since I already have a satisfactory unit) would be the long run availability of the actual electronic controls, stepper motors, etc.-- I am an electronics afficionado by hobby, and have been since very young, so am not (at all) put off by potential needs for repair, but I _have_ been put off by situations in which a circuit board or integrated circuit is not repairable and has been discontinued, rendering the rest of an otherwise still serviceable major appliance a big doorstop.
Yes! I am an electrician, electronics technologist, and power engineer. Figure the number of old controllers I've tossed out and and then had to reconfigure the system as the board and/or parts are not available anymore. There is such a thing as planned obsolescence in engineering design.
As many folks have found with vehicles, when the computer that reads the O2 sensor dies, you are dead on the road. No limp-home then. Same for these boilers unless the user can, and has acces to, adjust the primary and secondary dampers manually and hold them in place. I would wager a bet, based on LOTS of service experience, that the controllers for these boilers will be the achilles-heel. It is relatively easy to find the field parts for old control systems, like temp sensors, damper actuators, CO2 sensors, etc. But, try to find the controller board. Everyone with electronics is one power surge away from a dead system, not to mention the components inside dying for no special reason. Anyone lost a computer hard-drive or power supply? 'Nuff said. Plan for it, or expect the need for a back-up plan if you have a complex system.