In ,
Ultraglide typed:
I had a back-flow preventer installed last fall.

On what?

It works
fine but I have a question. There is usually about 1 inch
of water inside the housing.

What housing?

When I open up the inspection
cover, it drains away but more enters after a short while. My question is
this: Is this normal?

Depends on what it is, how it's assembled, and what the overall system
structure is.

If not what do I do
to resolve the problem.

You might start by putting together a clear, concise description of your
problem and a clear, concise phrasing of what you need to know. I suspect
it's a sump pump but that's a small part of what needs to be known.

-- How to Post to a newsgroup:
http://word.mvps.org/findhelp/whichnewgrp.htm

http://www.ehow.com/how_5681_post-ne...-internet.html

Sump Pumps 101:

http://home.howstuffworks.com/home-i.../sump-pump.htm

http://www.doityourself.com/stry/sumppumpswork

http://www.sump-pump-info.com/articles.html


HTH,

Twayne`