Main drain problem

[kopite]

I have air coming out of the skimmer jets for about 30 seconds each time the filtration comes on with the timer . There are no leaks in the pipe work . I have had professional to look at the problem he said it must be a leak on the main drain. He said turn the main drain valve off and that will stop the air coming out the skimmer jets. Well its turned off and the air comes out just the same as before . Anyone got any ideas please.
H

 

[PoolGate]

Skimmer jets is a little confusing. Are you referring to the return jets?

Do you have a saltwater chlorine generator? They create hydrogen bubbles which can build up in the plumbing.

 

[kopite]

I have air coming out of the skimmer jets for about 30 seconds each time the filtration comes on with the timer . There are no leaks in the pipe work . I have had professional to look at the problem he said it must be a leak on the main drain. He said turn the main drain valve off and that will stop the air coming out the skimmer jets. Well its turned off and the air comes out just the same as before . Anyone got any ideas please.
H

Yes the return Jets.
Yes it has a SCG
I have had two professionals one of them fitted a pool heater and the SCG there was some concrete that had to come out to allow an electric cable to go in and the bloke used an electric chisel to break through which was about a yard away (1meter) from the main drain where it goes underground to the bottom of the pool ,dont know if it disturbed the pipe. Probably not who knows.
The other bloke came he closed the main drain valve and said the must be a small leak in the pipe leave it closed and the air will stop coming through the return jets . He also said not to worry about the main drain valve being close as you don't need it and in the future you do need to use it just turn it back on. Well the air is still coming through it comes through for about 30 seconds no more when the filtration turns on .then it's just as it should be pure water. It must be a small leak because its hard to see if the pool level is going.
Thanks

 

[Bperry]

Yes the return Jets.
Yes it has a SCG
I have had two professionals one of them fitted a pool heater and the SCG there was some concrete that had to come out to allow an electric cable to go in and the bloke used an electric chisel to break through which was about a yard away (1meter) from the main drain where it goes underground to the bottom of the pool ,dont know if it disturbed the pipe. Probably not who knows.
The other bloke came he closed the main drain valve and said the must be a small leak in the pipe leave it closed and the air will stop coming through the return jets . He also said not to worry about the main drain valve being close as you don't need it and in the future you do need to use it just turn it back on. Well the air is still coming through it comes through for about 30 seconds no more when the filtration turns on .then it's just as it should be pure water. It must be a small leak because its hard to see if the pool level is going.
Thanks

Turning off the main drain valve would stop air from being sucked in through a crack in the drain pipe but it would not stop water from leaking out of the cracked pipe. That’s a somewhat silly response from your repair guy.

You can check the pump lid and any equipment on the suction side for leaks but it may just be the SWG or that air is getting in when the pump turns off. If the bubbles go away after 30 seconds I’m not sure I’d see it as a problem.

 

[Bperry]

Turning off the main drain valve would stop air from being sucked in through a crack in the drain pipe but it would not stop water from leaking out of the cracked pipe. That’s a somewhat silly response from your repair guy.

You can check the pump lid and any equipment on the suction side for leaks but it may just be the SWG or that air is getting in when the pump turns off. If the bubbles go away after 30 seconds I’m not sure I’d see it as a problem.

Also check your skimmers for excess debris or a stuck weir door. I had a suction leak from both of those as water couldn’t get in fast enough and allowed some air to get sucked in. Maybe have someone stand over at the skimmer when the pump turns on and see if there’s any evidence of that.

 

[Newdude]

Any connection is suspect, with the ones at the pad having been worked on being more suspect.

When the pump is off the filter slowly drains and forces that air out upon startup. Do you have an air bleeder valve ? You should be able to get more air out once the bulk of it had made it through the plumbing. Run the pump, bleed the air and then shut off the pump off and listen for any glugging.

On the pressure side you'd see any drips at the pad with the pump running. Do you have air bubbles in the pump basket when it's running ?

 

[Jimrahbe]

he said it must be a leak on the main drain.

K,

This appears to be a load of Bull Feathers to me...

As others have pointed out, air is getting into your filter and I really doubt that the main drain is the problem.

The first place I would look is the filter's air vent valve. Turn off the pump and put your finger over the vent hole and see if you feel any suction, or if you can hear air entering the filter.

Thanks,

Jim R.