Stenner Pump not Pumping

[davethomaspilot]

The pump motor runs and the rollers are squeezing the tube, but no acid is pumped.

I thought I just needed a replacement pump tube--that's been the solution in the past.

I put the same pump tube on the adjacent stenner pump (along with attached tubing) that's used to dose chlorine and it works--acid is dosed as expected.

Only thing I can think of is that the rollers have worn over time so they are smaller diameter and not longer squeeze the pump tube enough? Has anyone seen this?

(Hate to buy a new pump head assembly if that's not really the issue).

Thanks!

 

[PoolStored]

The pump motor runs and the rollers are squeezing the tube, but no acid is pumped.

I thought I just needed a replacement pump tube--that's been the solution in the past.

I put the same pump tube on the adjacent stenner pump (along with attached tubing) that's used to dose chlorine and it works--acid is dosed as expected.

Only thing I can think of is that the rollers have worn over time so they are smaller diameter and not longer squeeze the pump tube enough? Has anyone seen this?

(Hate to buy a new pump head assembly if that's not really the issue).

Thanks!

When this happens it is usually caking from the salts causing pickup or injection issues.

Here are a bunch of threads with all the types of failures to check:

Google search results

www.troublefreepool.com

 

[davethomaspilot]

Not that, because same tubing, same everything except different pump.

Reading the thread, thanks!

 

[davethomaspilot]

Process of elimination says it's gotta be the rollers.

I'm not hooked to an injector and suction side is just inserted into a jug of acid. And, I can blow through the tube with no problem.

Also, if I cover the other end when I blow, air doesn't escape, so there's no leak.

Besides--same tubes, same everything pumps great when the pump tube, suction tube, and output tube are moved to an adjacent pump

 

[colonelkirby]

I had a similar issue and replacing the roller assembly was the solution for me.

 

[davethomaspilot]

Actually, it's the inside hole that has enlarged over time. There's a lot of wobble and that would explain why the roller might not pinch the tube as tight as it should.

I forgot I had a spare--but so far I can't get the roller assembly off the pump shaft.

It looks like it should just pull off. I can get a screwdriver blade between the roller assembly and pump housing. I'm applying a lot of pressure--any more and I think I'll break off the plastic.

I got some squirts of WD40 so maybe tomorrow I can make some more progress.

There's actually a place where a set screw might have been planned. But there's no screw--it seems to be filled with plastic on both the new and the worn roller assembly (see below). I'll also try drilling that out.

 

[davethomaspilot]

Finally got it off. Just kept working round the shaft applying lots of pressure. Finally it just popped off all at once.

New roller assemble fixed the problem!

Looks like they are over $60. I might be able to punch the shafts out of the assembly an replace the rollers with 3d printed ones. Worth a try.

My chlorine pump rollers wobble a bit too, so if I can print the rollers and replace the old ones, I'll do the same on that pump. Otherwise, I'll wait until it fails.

 

[jprince924]

You are going to love this!! try looking at the rotation that the pump is turning. It should be rotating towards the pump outlet. If not, it is pumping air back into the acid tank instead of pulling acid from the tank. I had this problem when I upgraded from the shur-flo to the stenner. the pump must rotate in the direction of the arrows on the clear cover. If this is the problem, it is a dc motor so you can reverse polarity and the motor will spin in the opposite direction or you can simply reverse the tube in and out of the pump. Make sure this is the case because if you reverse incorrectly and the injection check valve fails you will over fill the acid tank and eat a hole in your deck. All of this has happened to me. Verify that the pump is feeding acid into the pool water!!! this is your responsibility and not mine. I have it reversed and everything is working. The stenner pump i received has a motor that spins opposite direction of the intended rotation of the pump. Pentair hasnt been any help. I am on hold with them right now for one hour. Good Luck!