Skimmer / Pump suction and pressure issues

[Huddles]

Heya,

Up until two weeks ago I knew nothing of pool maintenance until I decided to clean my parents' pool this year.
For two weeks, I've been solving problem after problem (mainly thanks to this forum) but I'm lost on this one.
First things first: we have a 75m³ inground pool with a 640 Kripsol sand filter.

I've been going crazy trying to find out why there was a bunch of air in my pump strainer basket.
I opened up the pump and there was a piece of rubber stuck in the impeller, blocking half of the entrance.
I removed the debris and thought I solved all the issues and I was the pool God.
Nonetheless, the problems were still present.

One day, I decided to clean out the skimmer to see if there was a difference.
Immediately the pressure went from 0.5 bar to 0.7 bar and most of the air bubbles in the pump strainer basket disappeared.
About an hour or two later, some leaves (not a lot at all) will have collected in the skimmer again and pressure will fall and air will appear in the pump strainer basket again.
If I remove these leaves, pressure will rise again and air disappears again.

What does this indicate? A (partially) blocked skimmer line?
I tried blowing out the line with a garden hose and a rag (they don't sell drain kings in The Netherlands), but to no avail.

Could this also have to do with the issue of the pool bottom being dirty again just 2-3 hours after completely cleaning it?

Other problems include (don't know if they are relevant): very low backwash pressure, pump sometimes not turning on in the morning and shortage in the circuit breaker when turned off, pump losing prime overnight, sometimes when switching modes on the multiway valve the pump will not turn on anymore

Thanks in advance!

 

[mas985]

Welcome to the forum!

What does this indicate? A (partially) blocked skimmer line?

Yes, a partially blocked skimmer. The leaves in the basket increase the suction in the pump basket which tends to draw in air as it gets harder to seal the pump basket. You might try lubing the pump lid gasket and drain plugs with silicon plumbers grease.

very low backwash pressure

Could be something is still stuck in the impeller. You may need to remove the motor and impeller from the wet end to clear it.

pump losing prime overnight

Air leak. Try lubing pump lid gasket and drain plugs.

Also, sounds like an electrical problem with the motor. So the breaker trips when the motor is shut off? Does the motor ever shut off on it's own?

 

[Huddles]

Welcome to the forum!

Yes, a partially blocked skimmer. The leaves in the basket increase the suction in the pump basket which tends to draw in air as it gets harder to seal the pump basket. You might try lubing the pump lid gasket and drain plugs with silicon plumbers grease.

Could be something is still stuck in the impeller. You may need to remove the motor and impeller from the wet end to clear it.

Air leak. Try lubing pump lid gasket and drain plugs.

Also, sounds like an electrical problem with the motor. So the breaker trips when the motor is shut off? Does the motor ever shut off on it's own?

Thanks for your reply!
I did take apart the motor last week and there was something stuck in the impeller.
Do you think something got stuck again in a week's time?

Furthermore, I have opened up the pump strainer lid and inspected the o-ring for cracks and what not, it seemed fine.
I used a silicon lubricant and cleaned the grooves and so forth. Issues still persist.

Yeah, the breaker trips after the pump will not turn on and I switch it off.
This problem occurred before, the first time I fixed it it by opening the pump strainer basket and manually moving the impeller, but that only worked once.
Other times I open the circuit breaker and press and hold a brown button, which manually activates the pump I think.
I hold it for about 5 seconds, then release it and it seems to work again by switching it on.
It rarely switches off on its own, usually I have problems in the morning after it was off for a full night or when switching functions on the multiway valve.

 

[mas985]

So what is the filter pressure before and after the skimmer fills with debris?

Also when you backwash, do you empty the skimmer first?

It sounds like the motor may be seizing. Does it make more noise than normal?

 

[Huddles]

So what is the filter pressure before and after the skimmer fills with debris?

Also when you backwash, do you empty the skimmer first?

It sounds like the motor may be seizing. Does it make more noise than normal?

I fixed the skimmer pressure thing by putting a sock over the skimmer basket. Pressure after is 0.7 bar, pressure before is 0.5.

I managed to get the pump up and running and ran it straight for 3 days.
Today I opened the pool and the bottom was very dirty, so I wanted to clean it.
I turn the pump off for the first time in 3 days, switch to waste and try turning it on again.
It won't turn on.
If I screw off the circuit breaker cover and hold a brown button in the middle of all the wiring, the pump will start running most of the time.
If I switch the switch, the red light just burns and the pump doesn't turn on, no hum whatsoever.
So the pump can run if bypassing the switch and holding the button in the circuit breaker directly.
Just now it wouldn't start while holding the button, I gave the pump strainer basket housing a hard bang with a hammer and it turned on.
In no way will it turn on via the switch though.
What does this indicate?

 

[mas985]

The bearings could be rusted. But if that were the case, the motor should hum when turned on even if the impeller does not rotate. However, when the bearings freeze, the motor will draw a lot of current because of the higher load so the breaker may switch it off before you hear the hum.

 

[Huddles]

The bearings could be rusted. But if that were the case, the motor should hum when turned on even if the impeller does not rotate. However, when the bearings freeze, the motor will draw a lot of current because of the higher load so the breaker may switch it off before you hear the hum.

So it freezes when flipping the switch, why does it not freeze when directly pressing the button (I still don't know what it's called) on the circuit breaker?


Edit: now it wouldn't start holding that button either, after a few attempts something whirred and it started, but there was an unpleasant smokey smell, so I released the button. I think my motor is dying, it's quite old and is likely due for a replacement

 

[mas985]

Is the breaker GFCI and the button you are pressing is the reset (yellow button)?

 

[Huddles]

Is the breaker GFCI and the button you are pressing is the reset (yellow button)?

Yes it is exactly like that.
Now when I flip the switch the light won't even turn on.


When I hold that button it just hums, hammer won't help either.
Is it time for a new motor?

 

[mas985]

There may be a ground fault in the motor. I would say yes, it is time for a new motor. But with the motor off, can you reset the GFCI so the yellow button is in?

 

[Huddles]

There may be a ground fault in the motor. I would say yes, it is time for a new motor. But with the motor off, can you reset the GFCI so the yellow button is in?

What do you mean with the motor off?
With the switch off, I actually have to hold that button for the pump to start working (humming in this case), as soon as I let go it stops (humming), has been like that since I first pressed it

 

[mas985]

Do you turn on and off the pump with the breaker only or is there a separate switch too?

 

[Huddles]

Do you turn on and off the pump with the breaker only or is there a separate switch too?

I don't know why I didn't just upload a picture straight away:

 

[mas985]

Ok so does that switch control the pump? If so, leave it in the off position and then reset the GFCI.