Jabsco 3.5 Par Max air in the system

[harryBon]

Hi All,

 

A couple of days ago my water tank was left to fully empty causing air to be drawn into the system. I have now fully filled up the water tank and have ran the taps in the bathroom, kitchen, shower and toilet flush. This flushed out a nice bit of rusty water along with the air in the system. The only thing now is the pump hasn't returned to its normal operation. Its taking about 6 seconds for the pump to kick when an outlet is opened and again around 6 seconds to stop after outlet has been closed.

 

I have checked the inlet filter from the tank to the pump and seem to be pretty clean. I assume there is still air in the system somewhere which is messing with the system pressure. Is this just a case of checking all points in the system and trying to bleed the air where i can? I.e undo a few nuts here and there to see if there is any trapped air? The taps and outlets are not spluttering anymore and flow seems to be pretty normal. The pumps is running with a lower hum then its usual higher pitch noise. Any suggestions would be much appreciated as will be tackling this in the coming days.

Edited March 2, 2021 by harryBon

[Tony Brooks]

5 minutes ago, harryBon said:

Hi All,

 

A couple of days ago my water tank was left to fully empty causing air to be drawn into the system. I have now fully filled up the water tank and have ran the taps in the bathroom, kitchen, shower and toilet flush. This flushed out a nice bit of rusty water along with the air in the system. The only thing now is the pump hasn't returned to its normal operation. Its taking about 6 seconds for the pump to kick when an outlet is opened and again around 6 seconds to stop after outlet has been closed.

 

I have checked the inlet filter from the tank to the pump and seem to be pretty clean. I assume there is still air in the system somewhere which is messing with the system pressure. Is this just a case of checking all points in the system and trying to bleed the air where i can? I.e undo a few nuts here and there to see if there is any trapped air? The taps and outlets are not spluttering anymore and flow seems to be pretty normal. The pumps is running with a lower hum then its usual higher pitch noise. Any suggestions would be much appreciated as will be tackling this in the coming days.

 

Is that six seconds with no water running from the tap or six seconds of water running and then the pump cuts in.

 

If the latter is sounds as if you have an accumulator and it's doing as it should.

 

If you don't have an accumulator then there is probably air somewhere, possibly in the top of a calorifier but that usually eventually disperses. I don't't think it's a problem.

 

If its six seconds before water flows then you may have debris behind the pressure switch diaphragm or the drilling to that diaphragm is blocked. If this is the case then I would fit a remote square D switch for long switch life.

Edited March 2, 2021 by Tony Brooks

[harryBon]

Its 6 seconds with water running then taps kick in.

 

I have an accumulator fitted but prior to the water tank emptying the pump would cut in and cut out almost instantly.

 

The other issue is the change in noise of the pump. Its now more of a mid/lower range chug,chug,chug rather then the higher pitch hummm 

[Tracy D'arth]

The pump and pressure switch holes are full of muck out of the tank.

[harryBon]

Very likely! What would be the best way to inspect/clean the pump and pressure switch?

[Tracy D'arth]

Take it all apart, blow out the passageways, or a new pump.  And then find out why there is muck and rust in the water tank.

Is it an integral tank? Been cleaned and blacked recently?

 

 

Edited March 2, 2021 by Tracy D'arth

[harryBon]

Thanks Tracey, so even though the inlet filter was pretty clear, muck could of still got through the filter and into the pump?

[Tony Brooks]

45 minutes ago, harryBon said:

Its 6 seconds with water running then taps kick in.

 

I have an accumulator fitted but prior to the water tank emptying the pump would cut in and cut out almost instantly.

 

The other issue is the change in noise of the pump. Its now more of a mid/lower range chug,chug,chug rather then the higher pitch hummm 

 

That suggest the pump is working harder and is thus running slower. It could either a restricted inlet making sucking water into the pump more difficult or it's operating against a higher pressure.

 

You have ruled out a blocked inlet strainer but it's not unknown for a steel outlet pipe stub on the tank to rust up or clog with debris - especially with an integral mild steel tank.

 

Operating against a higher pressure suggest the pressure switch is nto switching off in time, solved as @Tracy D'arth suggest.

 

[harryBon]

Thanks both, I will be tackling this next week Tuesday when I'm back at the boat so will update then.