So unless you have free electricity you are wasting power for a little bit of insurance for the few times the power might go out. Also considering you are worried about the heat, your UPS is probably less than 95% efficient, so the excess waste would be even higher. You should be able to determine to exact rating from the manufacturers specifications if interested.
The spike is almost non existent here so I am thinking to remove the UPS completely because it is not a well known brand like APC Triple lite, its a copy cat brand. it is a 690 watt UPS keeping 6 70 watt cards in it plus 100 watt of the board and all other components. I will check my utility bill of electricity for a month or two an decide what to do. UPS is running normal , never powering out so thank you all.
Buy yourself a cheap kill-a-watt or similar type of power meter and plug your UPS with miner attached into it and read the wattage draw. Then do the same with just the rig plugged in. You may be surprised at the difference, especially if it is a no-name brand with lower overall efficiency. Then determine if it is worth it or not. I have seen some real cheap UPS units tack on another 10% to overall usage, while some of the better ones are only 2-3% since they are mainly pass-through devices that consume a small amount to keep the batteries topped up most of the time. Relying on your utility bill is not a good indicator unless you have a very static consumption pattern.
Myself I only have a UPS to supply my router, switches, cable modem and a few server type PC's I use for nodes, proxies, and the like. I also have a UPS on my main PC I use to trade, but all my mining rigs are on their own with just a Tripp lite commercial rated surge suppressor for the 120V units, and I usually use commercial power strips or PDUs for my 240V rigs to provide surge suppression and delayed start capabilities in case of a sudden power loss. Trying to put a UPS on all of this would be costly, add extra to my power usage, and offer very little in terms of protection. Most modern PCs with a SDD or M2 card will not be too impacted by a sudden power loss as write to disk are pretty much instantaneous.