He's survived by his 3 sons -- Robin, Brennan and Carter ... and his wife, Tanya.
Alan played hockey regularly at a rink in Burbank. We're told he and Carter were on the ice around 11 AM when he started having chest pain, then got nauseous and vomited. The ambulance picked him up around 11:30 and took him to the hospital.
The Canadian born actor was most famous for his role as Jason Seaver, the dad on the '80s sitcom, "Growing Pains." Most recently, he was on the Netflix reboot, "Fuller House" ... and also had a cameo on the first episode of "This Is Us."
He was 69.
--more at TMZ.com