How hot does it heat up to?

Hello Wood, this unit does not have any temperature limit, the heat output is based on ventilation and space you are heating. It does have an oxygen depletion sensor so if it consumes a large amount of oxygen in the space, it will only shut off then and if you manually turn it off. If you need further assistance, just reach out by phone at 877-447-4768 or email here: http://www.ghpgroupinc.com/CTUS.html -GHP Group Customer Support