Last night I started noticing our heat pump was making very different and loud noises. We have a heat pump and a gas furnace and I can tell when the furnace comes on because a blue light on our thermostat comes on. Even though the light wasn't on, we did have heat. I went out to look at the heat pump and the fan would not come on. Can the heat pump be working if the fan doesn't come on? Is it dangerous for the fan not to come on? Also hot air was coming from the heat pump. What can I check to get it running properly?