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Home-pool filters
Fixing filter leaks
As long as filters are properly maintained, such as routine
cleaning, the
repair problems for filters are minimal. Although certain leaks may
occur in
valves, such as in the backwash, piston, multiport and rotary types
of
valves. A leak could also occur because of a problem with the
plumbing
system or a rotor seal.
For example, the backwash valves could leak either internally or
externally.
The leakage in the internal valves are usually a result of the
wearing down
of the O-rings, which will then cause water and dirt or DE to get
into areas
of the filter which could cause problems.
The piston backwash valves consist of discs that have O-rings. The
O-rings
on the valves eventually deteriorate due to consistent use. As a
result,
water and dirt may not flow in the proper direction. You may first
notice a
sign that water is leaking from the top of the shaft, or you may
have other
suspicions that the O-rings have deteriorated. If so, you need to
tear down
the valve utilizing the following procedure:
First of all, turn off the pump and take off the screws on top of
the valve
cap. Then, as in backwashing, pull the handle straight up until you
can
remove the complete piston component. Next, you need to replace the
O-rings
on each disc. You will notice that the O-rings will pull off like
rubber
bands and the new ones will go on in the same manner. Also, apply
silicone
lube to the O-rings.
Then the handle from the piston stem will need to be removed. The
handle is
held in by setscrews or allen head screws, which will enable you to
slide
the cap off the stem. There will be two small O-rings inside the
cap, which
you will need to pull out using the tip of a screwdriver; next
replace them
and apply a silicone lube.
Since dirt and sand can cause leaks and also cause the O-rings to
wear out
faster than normal, you will need to wash out the inside of the
valve and
clean the stem and disc component. Then put the unit back together
in the
same manner in which you took it apart.
Both the rotary and multiport valves are comparable in the manner in
which
they are made. The rotary valve is usually located under a vertical
grid DE
filter. They may leak within the unit itself or on the outside of
the unit
(as can the piston type units). Take a flashlight to look under the
filter
to see if you can notice any leakage. Feel underneath to make sure
there is
no leakage as well. If you notice a leak at the point where the
plumbing
goes into the valve openings, the leak can be fixed without taking
apart the
entire unit. However, if the leak seems to be at the joint of the
valve and
filter tank, or if DE and dirt are detouring the normal flow area
and going
back into the pool, the entire filter and valve will need to be torn
down.
Some amount of leakage may flow into the backwash side and appear as
a leak
if the body gasket wears out and causes water to bypass the normal
flow of
the system. If this is the problem, replace the body gasket.
If the valve is turned completely to the usual filtration point, and
if
leaking or dripping occurs from the backwash outlet, a rotor seal
could be
compressed or worn out. The leak may not be noticeable if the
backwash
outlet is plumbed straight into a waste or sewer drain. Thus, the
trouble
may be in a an area in the plumbing system and not actually in the
pool or
spa. This type of problem could cause the system to lose prime when
the pump
is not on. The leak could also drain all of the water out of the
filter
tank then out of the pump.
When you start the pump the next day, it will have no prime. If the
pump
runs dry for a few hours, it may overheat and loosen or melt the
plumbing
fittings. You may determine that the loss of prime is, in fact, due
to the
damaged plumbing, so you fix the plumbing, but the same difficulty
will
happen again.
To remedy some of these problems, it is a good idea to have a sight
glass on
the backwash outflow line. Then you are able to see leaks that may
occur and
there will be a shutoff gate valve that remains closed when the
valve is in
the normal filtration position.
In order to tear down this type of valve, follow these instructions:
Cut the plumbing so that you can separate the filter. Disassemble
the unit.
Look inside the filter and use a nut driver to take out the bolts
which hold
the compression ring. That will cause the valve to fall away from
the filter
tank. The valve body and rotor will be inside so you need to remove
the
handle on the underside of the valve. To do so, remove the bolt
component
that holds it to the rotor shaft. Slide it off of the shaft and pull
the
rotor out of the body. If the unit contains bronze rotors, you may
need to
take the valve to a pump shop, since they are very difficult to
remove.
Next, take some needle-nose pliers to pull out the old rotor seal
gasket
from the rotor. Then clean the rotor and inside the valve.
Lube the gasket with a silicone lube, then replace it in the valve
body.
(Make sure not to stretch the gasket.)
Note that with bronze rotors, each of the ports will have an O-ring.
On the
plastic types, they will contain one body gasket seal. Before you
put the
filter together, lube and replace some of the O-rings. Lube the
O-rings with
silicone lube in order to avoid dirt from going around the proper
direction
of the flow. Replace the O-ring that is located between the tank and
valve,
as well as the O-ring that seals the shaft where it goes through the
valve
body to the handle. Also replace the O-ring on the neck of the rotor
because
it seals the neck joint.
Next put the valve and tank back together in the same manner in
which you
took it apart. Inspect the tank to make sure it is clean and that
the
opening does not have any rust or cracks. If it does, clean it and
then weld
the cracks (or have them welded by a professional).
Lastly, replumb and restart the filter.
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