Shallow water jet pump very slow building pressure

[arnie]

I have a shallow well jet pump drawing water from the lake. The problem is that when the clothes washer draws water, the pressure drops from 50psi to 20, the washer fills very slowly after the 1st fill, and the pump has a very difficult time getting the pressure back to 50psi. I've replaced the foot valve, and the polyethelene pipe drawing water from the lake. All joints have double stainless steel hose clamps. I've opened the pump, and the impeller is in good condition. I've poked a wire through the injector and there is nothing blocking it. The dishwasher drawing water, or just drawing small amounts of water, has no effect, and the pump is able to get right back to the 50psi point but in these low usage situations the pressure drops very little from the 50 psi. The pump is 8 years old, and this problem started 2 weeks ago. Any ideas of what could be affecting this operation, would be appreciated.

 

[Bob NH]

It could be that your inlet fell down in the mud or got plugged up with weeds. Is there a screen on the inlet? Screens get plugged.

Or you somehow got a leak in your suction line that is letting in air. Check all of the above-water joints by putting something on them and see if it is sucked in while the pump is running.

 

[Sponsor]

 

[Speedbump]

If your using just a foot valve for a lake strainer, you could be easily drawing leaves, plastic bags etc. aroung that little screen. If your going to draw from a lake you need a real lake strainer.

bob...

 

[arnie]

Thanks for the replies. I've changed the suction line to new polyethelene tubing and have a new brass footvalve. All connections are double clamped with stainless steel clamps. I don't have an official lake strainer, but i do have a pair of pantyhose over the footvalve screen. I've used pantyhose for many years with good success. I snorkelled down to the footvalve, and there was no debris attached to it. I'll turn on the clothes washing machine on Monday just before i head to the city for a few days to if the pump can recover in a reasonable amount of time. I didn't want the aggravation of the pump not working over the weekend. Again thanks for the replies.

 

[Speedbump]

"but i do have a pair of pantyhose over the footvalve screen"


Why don't you just wrap duct tape around the screen on the footvalve. Then you won't have to worry about getting any water through it.

The screen on the footvalve is there to stop things that won't go through the pump. Anything that goes through will also go through the pump.

Now we know why your washer won't fill very well.

 

[Raucina]

She said the panty hose worked well for years.... so that should take that problem out of the circuit. certainly I would not wrap it around those crummy blue plastic foot valve screens - I would expand the area with a large slotted pipe and then get some big gal hose to slip over the assembly. 8 year old pump might have a worn or cracked impeller ... I use panty hose on airless pump pick up tubes and it flows paint quite well, granted at a low volume.

 

[Raucina]

and by the way the washer inlet screen needs to be checked - lake water will close that up in a few months.

 

[Speedbump]

I Agree, the footvalve will work good as long as no obstacles get sucked up to it by the increased velocity of water moving toward it when the pump is running. When it shuts off, and all the stuff falls off, it looks clean when he snorkles down to have a look.

bob...

 

[arnie]

The screens at the clothes washer machine are clean, thanks to a whole house filter that keeps stuff out of the lines. The foot valve screen holes are about 1/16 inch in diameter. They allow algae into the system and plug up the whole house filter in a couple of weeks. The stocking keeps a lot of the algae out of the system. I get about 6 weeks out of a whole house filter. I've used the stocking system on this pump and at my previous cottage pump for over 24 years. It's never been a problem. I suspect since the stocking is moving with the water currents, it cleans itself constantly. I've taken the pump apart and the impeller, injector, and other parts are clean and in good condition. Any other ideas?

 

[Speedbump]

There have been several replies to your questions. The stocking thing, the foot valve not being in itself a good lake strainer, the possibility of the screens on the washer being plugged, and now we know you have a "whole house filter" which is also a great reason for reduced pressure.

You tell us what you think is wrong.

bob...

 

[arnie]

The screens on the washer are not plugged at all. The system started acting up a couple of weeks ago. The foot valve and suction hose are all new to eliminate any possibility of the old ones being the cause of the problem.