The 15A is the maximum load for HS110, so 9A is ok to use on it.

Motors can be a bit tricky, the surge on startup can sometimes spark weld the contacts together and the relay will stop working. It is a fairly low end mechanical relay so probably will give out eventually. Unless it's been specifically protected against surge current flying snow?

Thanks for the response. What can be used to protect against surge current?

The motor is an inductive load which can generate large voltage spikes when the relay opens. There's a good discussion here on ways to control it http://www.yoctopuce.com/EN/article/relay-and-inductive-loads though unless you're into electronics and willing to modify it's a bit tricky. You might just use till it fails (if it ever does, depends how much you use it), then crack it open and replace the relay - I'm guessing but it's probably < $2. Another option is to use the TP Link to control a relay design for motors.