I have the same pump that is going on its 3rd year and I run it through
frozen winters. I would check for debris build up as this would explain
the intermittent faults. If a pump has fried it will stop working all
together ... not on and off.

Carl Beyer wrote:
I have a small pond that is doing quite well. I have a beckett 350 gph
pump that has been going nonstop for 2 years and is now beginning to
fail (it just stops running). This is a submersible. it runs h20
through a biological sand filter, and a UV filter. It may be a bit
strong for its use, a 250 might work just as well.

What manufacturer would you recommend as a replacement, and who would
you buy from?

Carl