Some dosing pumps stopped working

[derkon]

Hello,
I installed 2x4 pumps like 3 months ago and was pretty happy with them. Now I realised 3 of them stopped working anytime in between.
They seem to be clogged but they arent and they put out a fair amount of air pressure even when the other side is in liquid. It however seems not to suck on the end where it should.
The headers are fine and the tubes are intact, connections are tight and the pumps run. Inside the headers everything looks fine too.

I ordered a new header, switched it, same problem. If I take a functioning header of the old ones and put it on the same spot it works. If I put the broken one on another place at the pump it still doesnt work.
This is like the worst troubleshooting ever. I just eleminated every reason I can imagine:
- cant be the pump itself
- cant be the header or mechanism
- its not clogged (it actually happened to 2 liquids which are not prone to clogging and 1 which totally is)

Why doesnt it suck in liquid? Something here right over my head?

Edit: I just found out it starts working when I put the reservoirs higher. But why did they work properly and now some stopped?

Thanks in advance for any help.

 

[derkon]

J

Thread 'Auto pump head loud and not priming'

Apr 10, 2025

Hi,

Looking for help with the 4 pump auto doser. 3/4 of the pumps are working. The first one is just spitting liquid into the outflow tube. When I switch the pump head with a working one it works. Tried pulling down on the tubes and it doesn’t seem to resolve or change it.

I’m thinking it is the pump head/tube inside? Does anyone have any tips or suggestions?

Thanks

• JS1
• Replies: 17
• Forum: Questions & Answers

Seems like I kind of have the same problem he has, but a new header didnt help.

 

[EDGRU1]

Hello,
I installed 2x4 pumps like 3 months ago and was pretty happy with them. Now I realised 3 of them stopped working anytime in between.
They seem to be clogged but they arent and they put out a fair amount of air pressure even when the other side is in liquid. It however seems not to suck on the end where it should.
The headers are fine and the tubes are intact, connections are tight and the pumps run. Inside the headers everything looks fine too.

I ordered a new header, switched it, same problem. If I take a functioning header of the old ones and put it on the same spot it works. If I put the broken one on another place at the pump it still doesnt work.
This is like the worst troubleshooting ever. I just eleminated every reason I can imagine:
- cant be the pump itself
- cant be the header or mechanism
- its not clogged (it actually happened to 2 liquids which are not prone to clogging and 1 which totally is)

Why doesnt it suck in liquid? Something here right over my head?

Edit: I just found out it starts working when I put the reservoirs higher. But why did they work properly and now some stopped?

Thanks in advance for any help.

Hey, I also had today similar problem with head 2: I just connected it for the first time today. Out of the two pump heads, only head 1 works; head 2 sounds like it’s running but doesn’t aspirate any liquid.

I’ve tried several troubleshooting steps without opening the pump (to keep the warranty intact), but no luck so far.

@Chihiros, Could you please advise on the best next step?

Thanks a lot and all the best,

 

[Administrator]

Hello,
I installed 2x4 pumps like 3 months ago and was pretty happy with them. Now I realised 3 of them stopped working anytime in between.
They seem to be clogged but they arent and they put out a fair amount of air pressure even when the other side is in liquid. It however seems not to suck on the end where it should.
The headers are fine and the tubes are intact, connections are tight and the pumps run. Inside the headers everything looks fine too.

I ordered a new header, switched it, same problem. If I take a functioning header of the old ones and put it on the same spot it works. If I put the broken one on another place at the pump it still doesnt work.
This is like the worst troubleshooting ever. I just eleminated every reason I can imagine:
- cant be the pump itself
- cant be the header or mechanism
- its not clogged (it actually happened to 2 liquids which are not prone to clogging and 1 which totally is)

Why doesnt it suck in liquid? Something here right over my head?

Edit: I just found out it starts working when I put the reservoirs higher. But why did they work properly and now some stopped?

Thanks in advance for any help.

Technicians are checking, any update will let you know.

 

[Administrator]

Hey, I also had today similar problem with head 2: I just connected it for the first time today. Out of the two pump heads, only head 1 works; head 2 sounds like it’s running but doesn’t aspirate any liquid.

I’ve tried several troubleshooting steps without opening the pump (to keep the warranty intact), but no luck so far.

@Chihiros, Could you please advise on the best next step?

Thanks a lot and all the best,

The tube inside that pump head got stuck, you can pull the 2 yellow tubes firmly to solve that problem.

 

[Administrator]

Hello,
I installed 2x4 pumps like 3 months ago and was pretty happy with them. Now I realised 3 of them stopped working anytime in between.
They seem to be clogged but they arent and they put out a fair amount of air pressure even when the other side is in liquid. It however seems not to suck on the end where it should.
The headers are fine and the tubes are intact, connections are tight and the pumps run. Inside the headers everything looks fine too.

I ordered a new header, switched it, same problem. If I take a functioning header of the old ones and put it on the same spot it works. If I put the broken one on another place at the pump it still doesnt work.
This is like the worst troubleshooting ever. I just eleminated every reason I can imagine:
- cant be the pump itself
- cant be the header or mechanism
- its not clogged (it actually happened to 2 liquids which are not prone to clogging and 1 which totally is)

Why doesnt it suck in liquid? Something here right over my head?

Edit: I just found out it starts working when I put the reservoirs higher. But why did they work properly and now some stopped?

Thanks in advance for any help.

Need the SN code on the Dosing Pump.
And you can test the head you bought, blow air into the yellow tube to test for blockage.

 

[derkon]

Need the SN code on the Dosing Pump.
And you can test the head you bought, blow air into the yellow tube to test for blockage.

The situation changed a little: All pumps are working again (funny enough without really doing something) except the one with acid I already tried everything with. That one still needs the reservoir at the level of the pumps to pump anything, but its still 50/50 air and liquid coming out. Not to much of a problem since I manually add that until the pH is fine. Thats with the new header.
The new header is not blocked in any way.

The thing I still dont get: Where the hell comes the air from?

Any more troubleshooting ideas or steps? Want me to try the old header again?

SN: 8835120557

 

[Administrator]

The situation changed a little: All pumps are working again (funny enough without really doing something) except the one with acid I already tried everything with. That one still needs the reservoir at the level of the pumps to pump anything, but its still 50/50 air and liquid coming out. Not to much of a problem since I manually add that until the pH is fine. Thats with the new header.
The new header is not blocked in any way.

The thing I still dont get: Where the hell comes the air from?

Any more troubleshooting ideas or steps? Want me to try the old header again?

SN: 8835120557

Which store you bought it?

 

[derkon]

Which store you bought it?

German online shop: https://www.garnelen-guemmer.de/

Another Update: It doesnt work again even on the higher level.

 

[Administrator]

German online shop: https://www.garnelen-guemmer.de/

Another Update: It doesnt work again even on the higher level.

You can ask the store to replace the pump heads.