9. MAINTENANCE
Replacing the Flapper Valves
Step by Step guide for Koi Air 25
(See Diagram)
1. Remove the air filter cover part 1.
2. Remove the 4 screws from the air pump base part 7 and remove the lid. Check that the
cover lid seal part 5 remains in place.
3. Pull the L shape pipe parts 22/33 from the flapper valve chamber number 9.
4. Work on one outlet side of the pump at a time, remove the 4 screws from the valve
chamber part 9 and gently pull the part from the motor housing part 18.
5. If you have a complete valve base including flappers code number 1019835 (see getting
to know your KOI AIR 25 sections 2&3). This can now be directly replaced and the steps
repeated in reverse order to reassemble. Follow steps 3 to 5 on both valve chambers of
the pump, if not move to step 6.
6. Remove the flapper valve chamber board part 28 and pull out the inlet and outlet covers
from the valve base parts 30 and 31. You now have access to the flapper valves.
7. One at a time pull out the old flappers parts 10 and insert the new flappers on the same
side as they where removed, see diagram, and pull through until the locating lug has
locked the flapper securely in place.
Repeat the process on the other valve chamber.
Repeat steps 1 and 2 in reverse order to reassemble.
If you wish to replace the diaphragm, move to
replacing the diaphragm section 10.
Replacing the Flapper Valves
Step By Step guide for Koi Air 50 / 65
(See Diagram)
1. Remove the air filter cover part 1.
2. Remove the 4 screws from the air pump base
part 7 and remove the lid. Check that the
cover lid seal part 5 remains in place.
3. Remove the clips and L shape pipe parts 22/35
/23 from the flapper valve chamber number 10.
4. Work on one outlet side of the pump at a
time, remove the 4 screws from the valve
chamber and gently pull the part from the motor housing part 18.
5. If you have a complete valve base including flappers code number 1019859 (see getting
to know your KOI AIR 50 / 65 sections 4&5). This can now be directly replaced and the
steps repeated in reverse order to reassemble.
Follow steps 3 to 5 on both valve chambers of the pump, if not move to step 6.
6. Remove the flapper valve chamber board Part 9 and pull out the inlet and outlet covers
from the valve base parts 30 and 31. You now have access to the flapper valves.
7. One at a time pull out the old flapper part 10 and insert the new flappers on the same
side as they where removed (see diagram) and pull through until the locating lug has
locked the flapper securely in place.
Repeat the process on the other valve chamber.
Repeat steps 1 and 2 to in reverse order to reassemble.
If you wish to replace the diaphragm, move to replacing the diaphragm section 11.
Replacing the Flapper Valves
4
5
7
18
8
13
22
30
23
28/9
31
35/33
10/24
10/24
9/10
35/33
23
Koi Air Instruction Leaflet 2.qxd 30/3/06 13:51 Page 11
