Recently got the autocover installed, not loving how warm it keeps the spa

[brimorga]

Spa gets down to about 75 the next day, down to about 65 another day after that and at pool temp after about 3 days. I’ve noticed there is a big gap directly over the spa on the corner of the cover, probably acts like a chimney. Does anyone have any good ideas about how to permanently seal this gap without voiding my warranty? Something removable if I need to would be best.

 

[ajw22]

I would cut up a piece of styrofoam to fit that hole and remember to remove it before opening the cover.

Although I don’t think it will make much difference in keeping your spa warm. But give it a try.

 

[bmoreswim]

I agree on it not making much difference. Heat loss is mostly due to evaporation, which is caused by air contact with the water surface, which wouldn't really change by plugging the hole.