Blowing out pool lines -

[BKH]

I use an air compressor connected to the pump drain plug to blow out my pool lines. I have always blown out the lines with the multiport set to filter (after draining & cleaning my filter). This year I tried to blow out the lines with the multiport set to recirculate (before draining & cleaning my filter). However, I wasn't able to generate any air pressure through the system, and ended up just doing it the way I always have. I'm just confused as to why I couldn't do it with the multiport set to recirculate? What am I not thinking of?
Thank you!

 

[Texas Splash]

I'm surprised no one replied yet. I read your description a few days ago and honestly I couldn't think of a good reason either. Probably right in front of your faces. Maybe with this we can get some others to chime in.

 

[wireform]

I've too have been waiting on the side lines for a descriptive answer. Has there ever been work on the mpv or possibly a decal replaced that doesn't quite match up with your mpv stops.

 

[BKH]

I'm surprised no one replied yet. I read your description a few days ago and honestly I couldn't think of a good reason either. Probably right in front of your faces. Maybe with this we can get some others to chime in.

Hahaha - I kept thinking maybe I didn't post this correctly!

 

[BKH]

I've too have been waiting on the side lines for a descriptive answer. Has there ever been work on the mpv or possibly a decal replaced that doesn't quite match up with your mpv stops.

No, in fact, I had just been using recirculate to mix in winter chemicals, so I know the MPV is functioning as it should.

 

[wireform]

Possibly when going through the filter, then the filter acts like a buffer tank building volume and cfm where as going through recirculate the compressor doesn't quite have the necessary cfm to push a pipe filled with water. Don't know if I'm using the right terminology or if I'm even making sense but seems logical.

 

[BKH]

Possibly when going through the filter, then the filter acts like a buffer tank building volume and cfm where as going through recirculate the compressor doesn't quite have the necessary cfm to push a pipe filled with water. Don't know if I'm using the right terminology or if I'm even making sense but seems logical.

That's an interesting thought, because it did seem no matter how low or high I set the output pressure, the tank pressure would not build at all - as if the tank was just exhausting the air without being able to build up any pressure.