Accumonitors are guaranteed for 2 years. Matt and I usually dont even enforce the 2 year time limit. Even after 2 years, most issues are taken care of at little or no cost to customers. My cigar board friends get treated even better if they ever need warranty service.
When somebody has a problem, we expect there to be some communication between us and the customer who is having trouble. It might take 1 call or email, it might take a few, but we will fix anything that is broken.
If you look around on different cigar forums, you can see that the Accu is pretty popular for those making their own custom cabinets, and also for those who buy cheap, imported cabinets. In both of these cases, we do a get a higher % of calls regarding problems with the Accu, compared to Accus that are installed by Matt directly into Avallo Cabinets.
Most of these calls are about issues with uneven humidity, or readings not matching other hygrometers that are in their cabinet. Sometimes it takes more than 1 call to fix the problem. I can honestly say that in probably 8 times out of the 10 calls that I might get a year, I solve the problem right over the phone. In these cases, a new part would not have done anything. In the other cases, a new part or whole system is cheerfully mailed out to fix the problem.
Sometimes, problems are in the design of a humidor. Sometimes humidity will pool into 1 spot. Even with circulation fans, we have seen humidors that just had bad airflow, and a more complicated fix was needed. Sometimes a customer might need to just move his sensor to another location. Sometimes a canister might need to get moved. I would never try to take blame away from a malfunctioning Accumonitor, but we do like to go through a little bit of a process so that we are not replacing Accumonitors that are working fine. Its better for Matt, and its better for the customer. Remember that it can take days to see if moving a canister or sensor fixed the problem. Patience is needed sometimes to find the cause of trouble.
If customers have doubts about their Accu, and dont like emails and phone calls. they can always send it too me for a quick checkup/tuneup. I put it in my cabinet. check the readings. recalibrate it if need be. Test it for a few days. If broken, I fix it or send a complete new unit.