Hi,
I have a Wilkins Zurn 975XL backflow preventor installed on the
irrigation system. Had removed it for Winter and installed it this
month after the last freeze.

After installing the preventor, water has been flowing through the vent
below. I checked all the 4 valves and turned them to off position using
a flat head screw driver. The preventor is installed in the correct
direction, verified that with the arrows and compared it with my
neihbor

I verified that that sprinklers run when turned on, that eliminated any
blockage in the irrigation system. In fact water continues to flow
through the vent, when the preventor is disconnected from the
irrigation system.

Any ideas? Do I need to do something else to make the preventor work?

TIA

:-)abhi

TIA,
You need to get a plumber certified in back flow preventer testing and
repair. That is not a do it yourself project. THE BFPD is there to
prevent contaminated water from flowing into the mains if a low
pressure condition exists due to water main failure. Something like
that hapened in Pittsburgh PA years ago and sucked pesticides into the
water mains. A lot of people got sick, someone got sued for $millions
and they had to flush the mains for weeks. This is a safety issue, and
not just any plumber will do. Contact your water supplier for a list
of certified plumbers.

Stretch

wrote in message
oups.com...
Hi,
I have a Wilkins Zurn 975XL backflow preventor installed on the
irrigation system. Had removed it for Winter and installed it this
month after the last freeze.


Any ideas? Do I need to do something else to make the preventor work?

I probably has to be rebuilt. Inside are some seals and things that work to
prevent backflow in case of a pressure drop. In most areas it must be
done by and certified by someone that has the proper equipment to test it.
In some areas they must be tested once or twice a year by a certified
tester. Check your local code.

wrote in message
.com...
Hi,
I have a Wilkins Zurn 975XL backflow preventor installed on the
irrigation system. Had removed it for Winter and installed it this
month after the last freeze.

After installing the preventor, water has been flowing through the vent
below. I checked all the 4 valves and turned them to off position using
a flat head screw driver. The preventor is installed in the correct
direction, verified that with the arrows and compared it with my
neihbor

I verified that that sprinklers run when turned on, that eliminated any
blockage in the irrigation system. In fact water continues to flow
through the vent, when the preventor is disconnected from the
irrigation system.

Any ideas? Do I need to do something else to make the preventor work?

TIA

:-)abhi


Backflow preventors have movable parts which are subject to fouling,
wear and breakage. Although it is sometimes possible to buy repair kits,
local governments tend to be particular about who can fiddle with them.

In my town, only certified plumbers can service them. Our Code requires
me to have mine inspected and serviced every 5 years.

Mine flunked the standard test last year but he was able to lube some parts
and certify on the second try.

Regards
Old Al