 they're probably fine at six months but i would if you really want to make sure they're going to last a long time every three and run it until it's hot so you know fire it up i don't know what your if you've got a clutch where you can engage the pump and leave it off so you're not running it dry you might have to put some water in it but if you know and then you got to drain it for freeze protection but if it's a pump you can run