Guzzler pump problems

[Crik]

I am stumped. My electric guzzler pump has excellent vacuum and will start out working just as it should. Then after about 5 minutes it will not discharge the sap and the sap will back up the mainline. I have replaced the diaphragm as well as the inlet and outlet valves. I ran it unhooked from the mainline for some time and checked both the inlet and outlet with my hand and it worked as it should. Then when I hook it back up it will stop discharging after a few minutes again. Any ideas.? Thank you in advance!

[maple flats]

Try adding a recirculation line. For that make a line from the pump outlet back to the pump inlet. In that line have a needle valve. Adjust the valve so a small amount of sap flows from the outlet to the inlet. That will keep the diaphragm working and will prevent air lock.

[VTnewguy]

I had this exact problem. There are only 60 taps on this bush and it wasn't drawing enough liquid to keep it going. Added a recirc line and it has been working well. Instead of adding a ball valve i have a pair of lockjaw pliers pinching the line just a bit.

[Crik]

I have lots of sap though. The sap was running very good yesterday. I have had slower running days with no problems. This is 100 taps on 3/16 into 1” mainline, if that helps. How would I go about adding the recirculation line? I have 1” mainline on the inlet and outlet now.

[VTnewguy]

Take a piece of 3/16 or 5/16 and run from your tank to the front side of your pump. Use a saddle or whatever you use to connect the 3/16 to the mainline. Hope this helps.

[MISugarDaddy]

I don't use a Guzzler, but I was experiencing the same problem as you described with a Shurflo pump. It turns out, I had a small vacuum leak in the filter gasket connected to the pump. It was small enough that you could not hear it because of the noise of the pump running, but I removed the filter and my vacuum went up to 22" within a few minutes and the pump began to work as it should. Possibly that is causing your pump to act the way it is acting.
Gary

[SeanD]

I have lots of sap though. The sap was running very good yesterday. I have had slower running days with no problems. This is 100 taps on 3/16 into 1” mainline, if that helps. How would I go about adding the recirculation line? I have 1” mainline on the inlet and outlet now.

There's a similar problem that occurs with some Shurflo setups that I've been experiencing. The recirculation line could be a fix. The other possibility could be a droop or flat spot in your line coming in. It causes stalls and surges. For long periods of time nothing is moving and sap gets backed up in the line. Then suddenly the pump pulls a bunch of it through (though not all) and the process starts all over again. The gap between surges could be longer than 20-30 minutes, so if you are not there when it happens, you don't know it's happening. Do you have any sap in your tank?

On low flow days there is enough room in the pipe for air and sap to exchange, but on heavy flows or after a freeze when all the sap frozen in the pipe comes down at once, it backs up the inlet and you start surges all day.

I worked and worked at it and I still I couldn't figure it out. I would make the line steeper and straighter with no improvement. I even added a recirculation line. Then I found it. The droop or flat spot was the box itself. The line would come down to the box but because the box was sitting on a level surface, the whole line including the box was actually like a hockey stick. I stuck a brick under the inlet side of the box so that the pump box is at a similar angle to the line coming in. I had two setups with this problem and I'm back up above 20" with constant sap on both.

The recirculation line may be what you need in your situation, but this could be a ten-second troubleshoot that's worth a try along with it.

Sean

[Biz]

Glad you figured that out Sean! I think we were discussing this a little while back, right? The diaphragm pumps don't work well with any kind of sag or flat spots in the lines due to air pockets (except if 3/16 lines are used).

Dave

[SeanD]

Curiously, right after I posted that, I went out to clean the filter of one of the pumps. When I restarted - total lockup and nothing was moving. I have a ball valve before the box so I can hold vacuum and not get a box full of sap when I'm cleaning the filter. It ran all night, so the there was already a backup in the few minutes I was cleaning the filter. I waited and waited - nothing.

It might have cleared itself, but I had to get to work and I didn't want to chance it. So, what worked was cracking one of the quick connects just to let a hiss of air to rush in for a few seconds. That got the pump going again and it started dumping sap into the tank. I closed up the connection and the needle started to climb again while also moving sap.

[Crik]

Thank you all for your replies. Now I have several things to try to fix this issue. Doesn’t look like I will be able to work on it until Saturday, but I will let you know how I make out. Thanks again!