You were 2 for 2 on the worst companies in the industry, shaver is absolutely horrible. Free heat machine, biomass direct, whtever he calls himself now is ll the same crook, he changed names every other year to avoid ever honoring a warranty.
It's not a good idea to drain them in the spring and refill, it's best for it to be completely full of properly treated water all year long. Why are you having to add water all the time during the heating season?
I hate you've had these troubles, a quick google search for "shaver problems" would have showed you and endless mountain of complaints though. This is the kind of thing that burns my hind end tho, dealers out there peddling things they have no idea about, telling innocent folks how great they are, and the dealer probably doesn't know the difference anyway. Anyone claiming a 1/2" firebox is better doesn't understand the principle of heat transfer at all and if there saying you need 1/2" for longevity, then it's total junk to begin with. If you woulda got a good quality stove from the get go you'd still been heating and very happy, but, I'm sure at the time you thought you were doing just that. Bad companies and lying dealers bother me