Grundfos recirculating pump caught fire
I have a Grundfos Comfort Series hot water recirculating pump installed on the water heater. It was here when we bought the house so I don't know how old it is. A few days ago we noticed we weren't getting hot water, and I went out to take a look. The timer seemed to be set correctly and it was plugged in, but I didn't have time to investigate further. A few days later I went out to look again, and saw that at some point it caught fire. The timer side of the pump was completely burned away. I don't know when this happened, but I'm lucky the house didn't catch fire.
Until this happened we were pleased with the system--there's a drought here in California and we were wasting a lot of water waiting for the hot water, so I'd like to get another. But now I'm hesitant -- what would cause this to happen? Is this a known problem with Grundfos pumps?