Pump works great on recirculate dies out on filter setting

Pool pumps, pool filters and the plumbing of
swimming pools. Sand filters, cartridge filters,
fabric filters and alternative filter media.
bulletproofpoet

Pump works great on recirculate dies out on filter setting

Postby bulletproofpoet » Tue 23 Jun, 2009 20:44

Need some help. I have been an inground pool owner for the last 5 years and have never had the issues I am having this year.
My pool is light green and cloudy. I can not keep pressure when the pump is on filter. When on recirculate the water pressure is excellent forever.
I have tried backwashing over and over. When I do so I get a good 20 minutes of good pressure. I am getting about 17 psi on my gauge.
I personally feel it is somethingg to do with my sand filter since to pump works on all other settings.
Any help is greatly appreciated.

Chris


Swim Today Pool Service

Pump works great on recirculate dies out on filter setting

Postby Swim Today Pool Service » Wed 24 Jun, 2009 15:32

It sounds likes it may be time to change the sand. When your on recirculate the water is not being passed through the sand but just in and right back out of the head of the filter. You say that the problem goes away for a brief time when you back wash. Everything you describe leads to a conclusion that the sand filter is full and the sand can't filter any more. Even when you back wash only some of the debris comes back out not all of it and eventually the filter will remain clogged. Try replacing the sand inside the filter and that should solve your problem. Also while you have the filter empty be sure to inspect the inside stand pipe and laterals or fingers. It is the main center pipe you will see inside with a bunch of small little ones coming off of it. Make sure there is no cracks clogs or damages to these parts and replace them if there is. It is the sand that filters the water but it is these parts that the water flows through to be filtered and back to the pool. A damaged piece can reduce the water flow and cause sand to be blown into the pool via the returns. Chances are though just a fresh batch of sand should solve the problem.
cristinsane
I'm new here
I'm new here
Posts: 1
Joined: Fri 04 Jun, 2021 11:54
My Pool: 18000 gallons sand filter salt cell chlorinator above ground

Re: Pump works great on recirculate dies out on filter setting

Postby cristinsane » Fri 04 Jun, 2021 11:57

I am having the same issue so I changed the sand but it did not fix the problem
Denniswiseman
Pool Industry Leader
Pool Industry Leader
Posts: 2592
Joined: Tue 06 Sep, 2011 05:48
My Pool: 10k inground fibreglass, Telescopic Cover, Hayward Powerline pump, Quality filter with glass media, 27kw output heat pump, K-2006C test kit
Location: United Kingdom

Re: Pump works great on recirculate dies out on filter setting

Postby Denniswiseman » Sat 05 Jun, 2021 02:01

It seems the filter is doing it's job and is clogging up
Let's have your numbers (CYA is very important)
FC:
TC:
pH:
TA:
CH:
CYA:
Ripp6957
I'm new here
I'm new here
Posts: 1
Joined: Tue 15 Jun, 2021 12:56
My Pool: 24' above ground, sand filter unknown brand

Re: Pump works great on recirculate dies out on filter setting

Postby Ripp6957 » Tue 15 Jun, 2021 13:06

I'm having similar issue, but I just replaced it with fresh sand and some DE powder. Good pressure at start (no gauge) but 15 mins later hardly any pressure returning to pool. I back wash and rinse, good strong return pressure and then it dwindles to poor again in 15 mins.
I'm using the Clorox Filter Sand Plus. It says you use half the normal amount. My filter is just shy of half full of sand. And ideas?
Denniswiseman
Pool Industry Leader
Pool Industry Leader
Posts: 2592
Joined: Tue 06 Sep, 2011 05:48
My Pool: 10k inground fibreglass, Telescopic Cover, Hayward Powerline pump, Quality filter with glass media, 27kw output heat pump, K-2006C test kit
Location: United Kingdom

Re: Pump works great on recirculate dies out on filter setting

Postby Denniswiseman » Wed 16 Jun, 2021 05:00

Why doesn't anyone look at previous posts and start from there
It seems the filter is doing it's job and is clogging up
Let's have your numbers (CYA is very important)
FC:
TC:
pH:
TA:
CH:
CYA:
Hammerhead
I'm new here
I'm new here
Posts: 2
Joined: Fri 16 Jul, 2021 19:14
My Pool: 16 x 36 x 7 inground Gunite finish
VS pump (new) 3 HP
Triton TR60 sand filter (new)
Circu-pool salt chlorinator

Re: Pump works great on recirculate dies out on filter setting

Postby Hammerhead » Fri 16 Jul, 2021 20:01

I have this exact same issue. Pump runs great for about 20 minutes or so and then almost all flow stops. I have recently replaced my pump, my sand filter is new and added in check valves to eliminate flow back and keep the pump primed.
I have literally dug up all my lines (extended due to moving pump and filter to new location) which added about 15 feet more line for a total of 33 feet supply/return length. Head is about 1.5' above pool water level.
I noticed when digging up the lines to extend the lines coming from the pool proper the return is a 2" to the filter but is a 1.5" feeding the return jets. The original installers put an adapter on the 2" to 1.5" right at the demarc on the edge of my pool deck.
The supply lines feeding the pump are dual 1.5", one is main and skimmer and the other is the suction side port for vac. However, the main/skimmer is a 2" line that was reduced to a 1.5" at the same location as the return line (edge of pool deck).
This setup worked fine for the last 20 years or so (I bought the pool with a house thrown in the deal about 9 years ago)
The original setup had a 1.5hp pump, a three way Jandi valve for mixing supply side lines and the same filter as now.
I moved the pump/filter because the original installers placed the system directly outside my master bedroom wall (what were they thinking).
Just so everyone can rest easy, I had my pool water tested last week. CYA was little low and Calcium was a little low as well as PH being a tad high. Chlorine was good. With that said, I am not trying to pump mayonnaise through my filter. Water is fairly clear.
This seems to be a hydraulic problem that is mind boggling.
My current setup is:
VS 3hp pump 2" inlet/outlet
2" check valve 8" away from pump inlet.
1.5" Jandi on/off in vac line
1.5" Jandi on/off in main/skimmer
1.5"x1.5"x2" "T" combining the 2 Jandi valves into check valve and then to pump
2" to Triton sand filter (with flow switch) from pump
Multi-valve on sand filter 2" in/out
2" Check valve on return (before salt chlorinator)
2" salt chlorinator, bypass in place
I decided to wait on converting to salt until I fix the underlying issue with water flow.
I have removed the "new" sand from the filter (quikrete pool sand) and replaced with a different brand, HTH and the same issue is still here. I checked every joint for air leaks and found none. All the underground joints I sealed with silicone around the joint prior to re-burying. I have even put my old Triton filter back in service to dispel new filter issues.
No joy.
As stated in above posts, pump and water flow are outstanding when backwashing, straight to waste or recirculate. When the filter mode is engaged the system loses pressure after 20-30 minutes until almost no water flow is apparent.
Denniswiseman
Pool Industry Leader
Pool Industry Leader
Posts: 2592
Joined: Tue 06 Sep, 2011 05:48
My Pool: 10k inground fibreglass, Telescopic Cover, Hayward Powerline pump, Quality filter with glass media, 27kw output heat pump, K-2006C test kit
Location: United Kingdom

Re: Pump works great on recirculate dies out on filter setting

Postby Denniswiseman » Sat 17 Jul, 2021 03:20

Why does no one not check rhe simplest things
You say chlorine is good what about free chlorine and total chlorine?
Why has no one responded with a complete set of numbers. Not difficult if you go to a pool store
Hammerhead
I'm new here
I'm new here
Posts: 2
Joined: Fri 16 Jul, 2021 19:14
My Pool: 16 x 36 x 7 inground Gunite finish
VS pump (new) 3 HP
Triton TR60 sand filter (new)
Circu-pool salt chlorinator

Re: Pump works great on recirculate dies out on filter setting

Postby Hammerhead » Sun 18 Jul, 2021 16:22

[quote="Hammerhead"]I have this exact same issue. Pump runs great for about 20 minutes or so and then almost all flow stops. I have recently replaced my pump, my sand filter is new and added in check valves to eliminate flow back and keep the pump primed.
I have literally dug up all my lines (extended due to moving pump and filter to new location) which added about 15 feet more line for a total of 33 feet supply/return length. Head is about 1.5' above pool water level.
I noticed when digging up the lines to extend the lines coming from the pool proper the return is a 2" to the filter but is a 1.5" feeding the return jets. The original installers put an adapter on the 2" to 1.5" right at the demarc on the edge of my pool deck.
The supply lines feeding the pump are dual 1.5", one is main and skimmer and the other is the suction side port for vac. However, the main/skimmer is a 2" line that was reduced to a 1.5" at the same location as the return line (edge of pool deck).
This setup worked fine for the last 20 years or so (I bought the pool with a house thrown in the deal about 9 years ago)
The original setup had a 1.5hp pump, a three way Jandi valve for mixing supply side lines and the same filter as now.
I moved the pump/filter because the original installers placed the system directly outside my master bedroom wall (what were they thinking).
Just so everyone can rest easy, I had my pool water tested last week. CYA was little low and Calcium was a little low as well as PH being a tad high. Chlorine was good. With that said, I am not trying to pump mayonnaise through my filter. Water is fairly clear.
This seems to be a hydraulic problem that is mind boggling.
My current setup is:
VS 3hp pump 2" inlet/outlet
2" check valve 8" away from pump inlet.
1.5" Jandi on/off in vac line
1.5" Jandi on/off in main/skimmer
1.5"x1.5"x2" "T" combining the 2 Jandi valves into check valve and then to pump
2" to Triton sand filter (with flow switch) from pump
Multi-valve on sand filter 2" in/out
2" Check valve on return (before salt chlorinator)
2" salt chlorinator, bypass in place
I decided to wait on converting to salt until I fix the underlying issue with water flow.
I have removed the "new" sand from the filter (quikrete pool sand) and replaced with a different brand, HTH and the same issue is still here. I checked every joint for air leaks and found none. All the underground joints I sealed with silicone around the joint prior to re-burying. I have even put my old Triton filter back in service to dispel new filter issues.
No joy.
As stated in above posts, pump and water flow are outstanding when backwashing, straight to waste or recirculate. When the filter mode is engaged the system loses pressure after 20-30 minutes until almost no water flow is apparent.
FC:4.64
TC:4.64
pH:7.8
TA:128
CH:79
CYA:5
Denniswiseman
Pool Industry Leader
Pool Industry Leader
Posts: 2592
Joined: Tue 06 Sep, 2011 05:48
My Pool: 10k inground fibreglass, Telescopic Cover, Hayward Powerline pump, Quality filter with glass media, 27kw output heat pump, K-2006C test kit
Location: United Kingdom

Re: Pump works great on recirculate dies out on filter setting

Postby Denniswiseman » Mon 19 Jul, 2021 02:27

To get FC and TC excatly the same doesn't seem right
After backwashing is the flow OK through the filter temporarily
Do you notice any air in the pump pre filter
terminato1
I'm new here
I'm new here
Posts: 1
Joined: Sun 12 Jun, 2022 11:22

Re: Pump works great on recirculate dies out on filter setting

Postby terminato1 » Sun 12 Jun, 2022 11:30

I had same problem. Took apart whole pump. Found the pre-filter to be clogged. It's the piece between the sand tank and the top part with the setting lever. Just remove the clamp that holds them together and take out the white piece. Give it a good cleaning. My pump went from zero to 100 after. Before it would only pump good for about 5 or 10 mins before flow reduced to nothing. Hope this helps someone as I know the frustration.

Return to “Pool Pumps, Filters, Plumbing & Piping”

Who is online at the Pool Help Forum

Users browsing this forum: DotNetDotCom.org [Bot] and 7 guests