Extended Power Outage....this could mean many things and depending on the outside temp could be handled many different ways. If it's a few hours and 20-30 don't sweat. if it's 6-8 hours no problem. If it's 12-24 a light bulb for the tub off a gen set or a drain, but if it's -10 to 10 above better start worring about your house and your life, water pipes, water heater and get the tub out of your mind by draining. I have lived in Northern Minnesota for 30 years and have only seen a few power outages in sub 0 weather but the hot tub was the least of my worrys and never did they last for more than a few hours. I have seen plenty of early winter and late winter ice storms that have taken power out for a day or 2 or even 3 but the outside temp was then 20-40 No worrys. If you have a tub problem that forces a shut down contimplate quickly in your warm house as to how quick a service guy can get there or when you need to drain. I would er on the side of a drain. But a small heater or light bulb in a small equipment area will extend your decision. There's many answers here and if you need freeze advice in my service area I am a phone call away to anyone interested.
Had a customer a few weeks back and there tub was down because of a pump motor failure (which they didn't know at the time) On the phone based on the outside temp and my response time I recomended draining and went there to install an electric heater inside the cabinet (non FF) At that time I recognized the pump failure and as it turned out they had a freeze problem already started because the gate valves would not close, as the tub had been shut down for a week, this I just found out when I got there. I extracted the pump and motor and left the heater to do it's job of thawing the lines to the pump. I also had the control box and heater with me, and told the homeowner to check the heater in an hour and another hour and so on untill I got back. The heater was safely sitting on top of a wooden box I use to keep it out of the water as it thaws. I could not return until the next day but had a new pump and motor with a thawed heater. When I opened the compartment it was about 80-90 inside and very wet as the lines had thawed completely. Installed the new pump and motor and re-installed the control and heater and started to fill. Knowing that there could be plenty of other leaks. But alas none appeared and the customer was very very happy. 400 dollar pump and motor slightly marked up and 100 bucks for my time. And a very very happy customer that will call me again if or better yet, when, they have another problem.
