Surflow diaphragm comes on and pumps water shuts off then comes on in 2 seckonds again. It does through this cycle 5 or 6 times then goes off. It will do this through out the day.

Difficult to work out how you are using and wiring this? The pump is under the sink but you have 30 feet of wire going outside? My guess is that the filter is causing too much back pressure and cutting it off. Then pressure is vented off through the filter and it starts up again. Are you using this with a pond? Not an application for this pump I don't think.
https://www.northerntool.com/shop/tools/product_200647933_200647933

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CONTROL BOARD POSSIBLY

check the small tube to the level pressure switch
check the switch is working
check/replace the water control solenoid / diaphragm
tests are
with out clothes
select a low level wash
listen as the water flows in
when the tub is about 1/2 full the water solenoid shouf make a clunk sound and the water cuts off
at the same time the wash cycle begins
if the water comes right up and there is no solenoid sound then check the small tube or the water level switch
if there is the sound but the water continues replace the diaphragm in the solenoid

Nancy... This is how I have mine set up... I have a cheap Home Depot Timer that I use for the Filter/Pump the comes on at 6:00am in the morning and goes off at 12:00 pm... This Timer is very simple to use... For the Salt water System, For the first time I turned it on was at 6:30 AM (before work) and set it for 5 hours... Once is has completed the 5 hours, it will go into Sleep Mode and automatically start 24 hours later, so in my case, it will start the next day at 6:30 am... So i have have my Filter/pump come on 1/2 hour before the salt system comes on and it goes off 1/2 hour after the salt system goes off...

Hope that helps.
Dan

the water control is by a diaphragm that is controlled by a solenoid
when the solenoid is activated , a small needle unblocks a hole and the diaphragm opens to allow flow
when the water is shut off the needle blocks the hole and the incoming water closes the diaphragm off so stopping flow.
sand will affect that operation so new valves ($20.00 approx ) will fix that problem or maybe just pulling the diaphragm section off and cleaning it out
next the filters in the inlet hoses are under the rubber washers so pull the washer out and the filter will come out
next if you have a mains supply problem, the answer is to fit a big blue filter ( 4" X 20" ) paper element filter to the house supply line
that will filter out any dirt and rubbish down to 10 microns and if you go a carbon filter down to around 3 microns ( around hair thickness size)plus and taste
as for the water in the tub problem , you may have to get a technician in as that would be the program not shutting of the inlet water while spinning or a pump not operating correctly ---blocked inlet or inlet filter

sounds like tank problem or maybe air is to high in tank

Fuel starvation - 'lean fuel' condition
Basic things to check:
1) spark plug
2) spark arrestor in muffler
3) fuel lines and tank filter
4) turn adjustment needles out (counterclockwise) 1/4 to 1/2 turn
Chain Saws:
5) check impulse tube and intake boot for cracks or leaks
*if all of the above are OK and/or do not improve performance then:
Remove Carburetor
6) replace gaskets/diaphragms
a) use a spray carb cleaner to clean jets, holes, and body of carb
b) fuel pump diaphragm goes against the carb body,
then the gasket towards the outside
c) metering gasket goes against the carb body,
and the diaphragm goes towards the outside

I’m happy to assist further over the phone at https://www.6ya.com/expert/rolandw_c013176d62ee17ae

Fuel starvation - 'lean fuel' condition
Basic things to check:
1) spark plug
2) spark arrestor in muffler
3) fuel lines and tank filter
4) turn adjustment needles out (counterclockwise) 1/4 to 1/2 turn
Chain Saws:
5) check impulse tube and intake boot for cracks or leaks
*if all of the above are OK and/or do not improve performance then:
Remove Carburetor
6) replace gaskets/diaphragms
a) use a spray carb cleaner to clean jets, holes, and body of carb
b) fuel pump diaphragm goes against the carb body,
then the gasket towards the outside
c) metering gasket goes against the carb body,
and the diaphragm goes towards the outside

I’m happy to assist further over the phone at https://www.6ya.com/expert/rolandw_c013176d62ee17ae

You,ve done a good job the first time the pump fail MikieM. You can do it again. We sometimes forget to empty our pocket. Some small metal things could have gotten into the pump...could be other hard foreign object. Good luck.