Koenders Windmill Troubleshooting Steps

1. Check air stone - Is it heavily soiled or damaged?

Yes – Clean or replace -- Cleaning instructions
No – Continue to step 2

2. Observe the check valve on top of the airstone – Is it damaged? Any blockage? Check the brass one-way valve insert inside for functionality.  

Problems – Clean or replace
All good – Continue to step 3

3. Check the full length of airline tubing for chew marks, cuts, cracks.

Damage found: splice in a new section of tubing or replace
No visible damage – Continue to step 4

4. Disconnect the airline at the pressure release valve. Try blowing air down toward the stone in the pond using an electric compressor.

No air passage: the line is likely blocked. You may be able to locate the blockage and remove that section of line, or replace the line altogether.

Airstone bubbles in the pond – Continue to step 5

5. Reconnect the airline. Put the airstone into 1-2ft of water and watch for bubbles when the fan spins

If there are no bubbles, the compressor is either not generating enough pressure or is not connected to the airline. 

Bubbling only in shallow water indicates the compressor not building up enough pressure

Continue to step 6

6. Tie off the compressor fan so it can't spin or swivel. Ensure the airline at the compressor is in good shape, not kinked, and is still attached to the bottom of the compressor pipe as well as the elbow at the top.

Airline damaged or not attached – trim damaged line off and reattach
Connections are good – Continue to Step 7

7. Open up the top of the compressor and appraise the one-way valve inserts (one or two inside, depending on the age of your windmill.)

Inserts are working properly – Continue to step 8
Inserts are not working - replace.

8. Check the diaphragm for wear: cracks, splits, holes.

Diaphragm is not in good condition – Replace. Note the style, take a picture, or take the diaphragm with you to purchase a replacement to ensure a proper fit.
                       Diaphragm replacement instructions

Diaphragm is in good condition – Continue to step 9

9. Take a look at the brass check valve that is on the top of the can. Ensure it is functional (you can suck air through it but not blow through it).

Brass check valve is not functional and needs to be replaced - the top screws open and the small inner parts can be replaced.
Brass check valve is functional – Continue to step 10

10. Remove the silver backing on the compressor. Is anything broken inside?

Yes – Replace 
No – Continue to step 11

11. If you still have not come to a resolution, give us a call and we will discuss it.

 Please see our selection of commonly needed parts. If you need to replace something that isn't here, please give us a call and we can help.

Have Question? We Can Help!

If you have question after reading this article please let us know. We would be happy to help discuss the appropriate products to help you.