How to fix rena air 400? (little airflow)

Broggy

I know, its an old pump, but i want to get it working. anyways, it has very small air flow, it can barely make a bubble under a centimeter of water. i just opened it up and it looked ok, but it was pretty dusty. so ill bet its clogged up somewhere, I looked at the suction cups, and the magnetic arms... all working. so if anyone is farmiliar with this model pls help me out
 

Mongo75

I did a quick google and you may be able to get a tune up kit for it. Though they may look good, the air block and diaphragms my be shot, and those two parts are what comes in the tune up kit. Due to it's age though, the tune up kits may be hard to find...
 

Wickette

I know, its an old pump, but i want to get it working. anyways, it has very small air flow, it can barely make a bubble under a centimeter of water. i just opened it up and it looked ok, but it was pretty dusty. so ill bet its clogged up somewhere, I looked at the suction cups, and the magnetic arms... all working. so if anyone is farmiliar with this model pls help me out

As stated, tune up kit is your best bet. You can do some basic troubleshooting.


-Stuff you probably did but just making sure. Test it at full flow with 2 lines at the same time, both about the length, same age, submerged the same amount. Don't connect the tubing to check valve, air stone, filter etx. As these things age they get worse at regulating pressure between each output, if you merge the lines together or only hook up one air line or make one significantly shorter it may create back pressure and not push at all.

-are the airlines fitting tightly, if theyre loose either because the tubing is stretched out or the outlets are just old dont form a good seal anymore, you will lose a lot of pressure. You can air tubing in boiling water or use a blow a hair dryer on it for 2 minutes to shrink the tubing ends, get it real snug again.

-Is the intake filter dirty/clogged. Not sure on that model, but its usually a woolpad,sponge, or porous fabric that pops out. If you can pop it out, run it without the filter, if it doesnt pop stab it with a needle a few dozen times to allow air flow.

-Air could be getting in or out through the casing. You can test that by putting tape around where the top and bottom parts meet, over the screw holes, around the electrical cord. (electrical and duct tape work great any tape should work). This isnt a fix, but if your airflow goes up, youve found the problem. If thats the problem can replace the tape with latex or painters caulk (those can be scraped off with some rubbing alcohol and a knife, silicone will seal better but is permanent)

-SInce this is an older model, theres a good chance the seals and diaphrams are dirty, dryed out, cracked, crumbling. Rub the diaphram or those black rings on the valve black a piece of paper and the paper, if the black smears onto the paper or fingers like its charcoal, its too far gone, you need the tune up kit.

--if its does rub off badly, you can ghetto tune up the existing diaphram/valve block. Clean it with water and a drop of dish soap and dry it.
Then wrap some teflon tape around: 1)the part of the magnetic arm the diaphram slips onto. 2)around the valve block the other side of the diaphram goes over. 3) You can even wrap some teflon tape around the assembled deiaphtam and valve block so that the black washers and the valve block are both covered with the teflon tape.
Alternative or with the teflon tape you can get all the micro-cracks filled up with Vaseline or plumbers grease. (you'll need to use your own discretion what parts need lubricating and what parts will do better with teflon tape. Teflon tape acts like a really really thing washer, vasaline/grease rejuvenates old seals.

-make sure the cable is well attached to the coil.
-you can clean the copper coil and the exposed cable with alcohol, let it dry over night before testing.


If the problem is with the motor/electrical its a much bigger hassle to fix.
 

Broggy

wow that is very helpful thank you... sadly, i have already disassembled it for parts lol
 

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