ShurFlo 5.7

[Ryan Wright]

Hi folks,

I've got a problem with my relatively new ShurFlo 5.7 water pump.
ShurFlo doesn't know what to tell me, other than to send it back to
them, but before I do I'd like to see if anyone here has experienced
similar behavior.

The pump runs for about 30 seconds, then cuts out for a couple of
seconds as if it's reached it's target pressure despite my faucet
being wide open. Then it runs for 5-10 seconds, cuts out, and repeats
this behavior indefinitely. If I open more faucets, I can hear the
pump boost it's operating speed and it runs slightly longer between
cutting out. After a few minutes of this on & off behavior, the stops
become more abrupt and I can hear a relay inside the pump flicking off
during each cut.

Anyway, I'm assuming the pump is faulty and will be returning it to
ShurFlo, but I did want to ask here first. I thought these pumps were
supposed to adjust their speed in real time to deliver just the amount
of water needed, not shut down entirely? My intention is to buy a new
one right now and keep this one as a spare after ShurFlo replaces it,
but I'm also concerned of the remote possibility I bought too much
pump for my coach's plumbing system and a new one won't behave any
better. What do you think?

-Ryan
'86 PT-40 8V92