@Andrea4731 Normally if there is an actual missing amenity, like the pool heater broke, that would warrant a discount, but it's always best if the host offers that discount right away, rather than waiting until a guest asks, which shifts the dynamics and gives the guest a sense of having some sort of power.
But in this case, the heater is woorking, it's just not up to a temperature that the guests find comfortable. I don't know anything abouut pools and rarely swim in them, so don't know if 80 degrees is a water temp I'd feel comfortable in- if Linda here says she would find that too cold, I would take her word for it, at least for me, as I'm always chillier than most people.
What if the guests don't want to leave? Well, the general rule of thumb is that guests who are being a pain in the butt are best gotten rid of ASAP. If their behavior is really egregious, which this situation isn't, it's often worth taking the penalties for cancelling yourself just to get them out. Or as suggested, try to get them to cancel by offering to refund unstayed nights.
Guests who can't be adaptable and roll with the punches when something happens outside a host's control, like an unusual massive cold front, are annoying.
But if you want to keep this booking smooth, and can't get the pool temp up, I would offer them a 10-20% discount if they cwn't use the pool.
(Don't call it a refund- a refund is what is given if a guest doesn't stay- a discount is given if there is something that negatively affects a guest's enjoyment of the place. Just like you might get a discount on a slightly damaged item from a store- you'd only get a refund if you bought that something that turned out to be defective and you brought it back. I think terminology is important because it psychologically affects the way people think about things. There are far too many guests angling for "refunds" these days. )
