regardless of it being room-sealed I don't believe you can have a woodstove in a room which has an extractor of any kind. Read the B-Regs very closely for your jurisdiction...
there was certainly a massive range of levels of completeness and support when we were dealing over ours. I'm really glad we went with our second option. @Kevan Marshall drop me a PM if you want an overview...
one could always try not even moving the thermostat but just turning it up a few degrees. Wherever the tank is will still track the rest of the house, even if it's a wee bit higher...
I had a makita-fit 6" chainsaw that came from the south american river shop and got a couple of years out of it till the brushes went catastrophically in the motor
replaced it wth a similar one but BL this time and it was under £30 with two batteries, a slow charger, and a spare chain...