Flow Problem

[Jimbolo]

Hello All, First time pool owner. Been lurking here for a few weeks and learning tons. THANKS!! Now the problem:

Just like another poster, I vacuum through the hole in the bottom of the skimmer. After 10 minutes suction goes to nil. Not vacuuming debris, just dirt.

Two weeks ago when I first moved in and started messing with the pool (clear but very low chlorine), I could get the water to return to the spa and it would flow heavily over the fall. If I returned to the pool, I would notice the ripple from the jets and see a whirlpool start. Vacuuming was strong.

But now the return pressure has gone way down. Don't see ripples when drawing from the skimmer and/or main drain and returning to the pool. Doing the same but returning to the spa gives me light waterfall, but not like it was.

I messed with the valves not knowing what I was doing for the first ten days. I may have starved the pump or shut off return at some point and it may have gone more than a couple of days that way.

Only today when I pulled a valve apart (put it back correctly with no leaks) did I really understand how it works. The labels were worn off and my conventional knowledge of how ball valves work was incorrect in this case. I was able to take the screws off the top of the valve (single return that comes from the heater/tablet dispenser where it splits off to spa/pool return) and turned on the pump and expected a geyser. There was only a moderate flow at about 3-5 gallons per minute. I could leave the valve off and watch the water flow by. But 3-5 gallons/minute doesn't seem like enough to push the pool jets. The pressure from the jets is really weak even when that's the only return selected.

Have cleaned the skimmer basket, filter, pump basket.

I didn't notice this when I first started working with the valves (back when pressure was strong), but now there seems to be an intermittent "bad bearing" noise coming from the impeller housing. Intermittent meaning 3-4 out of 10 seconds at 1 or 1.5 second bursts. Pump noise is what I would expect and steady.

Here's what I have:
In-ground pool, approx. 12000 gallons.
marathon electric pump, 1.5hp
Hayward C1200 cart filter (runs at 35 psi when clean)
3 inlets (main drain, skimmer, cleaner)
Water comes in from pool, through pump, through heater (haven't tried it), past tablet dispenser, then a T valve that allows me to return to the spa alone or spa/pool (two on one side of the T, spa on the other).

That's about all I know and have witnessed. Anyone want to take a crack at troubleshooting?

Thanks a ton for everything so far!!

Jim.

 

[duraleigh]

Hi, Jim,

Welcome!! What is your current psi on the filter guage and what was it before the problem began? Also what type filter. That'll get us started.

 

[Jimbolo]

Hi Dave, Thanks for the quick reply. Currently it's running at about 35 psi. And I think it was about 30 10 days ago when the pressure was strong.

 

[JohnT]

30 or 35psi indicates a problem. Either you have a valve closed that is restricting flow to the pool, or your cartridge probably at the very least cleaning, and I'd almost bet replacing.

 

[Jimbolo]

Hi John, I have checked the flow from start to finish, except where I can't get to like where it goes into and out of the heater. I have no way to bypass that.

The filter is clean. I sprayed it with a hose nozzle and there is no residue or algae. There is no debris in the filter housing.

What else should I check?

 

[Jimbolo]

Sounds crazy, but should I momentarily flip the pump on with the filter out just to see what kind of output the pump is making? Should I blast a hose in the filter housing "out" pipe to see if that may be restricted somehow? Like I said, I can't check for clogs between the filter housing out pipe and the valve after the tablet dispenser (which in my first post I said that I removed the valve after the dispenser and flow was 3-5 gpm). If there is a clog, it may be somewhere in there.

If the pressure is high, does that mean the pump and impeller are doing what they're supposed to?

 

[duraleigh]

To add to what john said, and assuming your guage is not broken. you have a pressure side restriction. That means somewhere between the pump and where the water goes back into the pool, it is being restricted causing that very high psi.

If your psi indicated 30 and you had strong flow, then I strongly suspect the guage is faulty. Does it go to zero when you turn the pump off?

Is it possible the filter was not reassembled properly? I am not too familiar with cartridge filters but that might be a possibility. Of course, a closed valve is the usual suspect but you indicate you have checked that.

Do you have a multiport valve that you can re-position to "bypass"?

 

[Jimbolo]

Hi John, I reassembled the filter the way that I believe that it came out. The threaded rod and the air relief tube coming up through the middle of the cartridge.

It seems to me that the flow pattern is pump>filter>heater>tablet dispenser>valves for return. If the pressure in the filter is high, but at the valve after the dispenser the flow is lazy, is it possible that the heater is clogged up with debris or mineral build-up? I don't understand how the dispenser connects to the return line, but is it possible there is a blockage at the tablet dispenser?

Thanks for your help!

Jim.

 

[Jimbolo]

Troubleshooting - So in an effort to find out where the bottleneck in my system is that's causing the high filter pressure but low return flow, I'm going to troubleshoot by whittling the problem down. I need to first eliminate the filter as the problem. Here is question 1:

Would anyone see any problem in removing the filter cartridge, sealing the housing back up, and running the pump for 30 seconds or so? If pressure went WAY down, that would tell me that the seemingly fine filter (clean and in good shape) may nonetheless be the problem.

Question 2:

If that doesn't solve the problem, I'll put the cartridge back in and move down the line. I'm running at 35psi right now. If I close all return valves and pressure does NOT go up notably, then can I assume that there is a blockage between the filter and the return valves?

Thanks everyone!!

Jim.

 

[Bama Rambler]

It makes sense to remove the cartridge. It's probably the easiest thing to do. Make sure there are no loose pieces in the housing with the filter out.