Our Smart Sensor water pump, #4900-0201, cycles briefly every 30 seconds or so. It is a short burst each time, approximately 1 second. I assume there is some grit in one of the valves or something similar, but have not purchased any repair parts or torn it down yet. Anyone have some guidance on this. We are on the road so I want to only pull the pump one time to make the fix if I can. Maybe I don't need new parts, rather clean it out?

It sounds like you have a leak. If you can not find one in the plumbing it may be a leaking check valve in the pump.

dbbls wrote:It sounds like you have a leak. If you can not find one in the plumbing it may be a leaking check valve in the pump.As just said, you described a classic sign of a water leak. Time to trace out all water lines.

You have a small leak.......could be at a fitting, could be toilet water valve, could be dripping faucets/shower head, could be drip at low point drains, could be dripping at 'city water' inlet check valve, could be water heater PRV weeping etc.Could be pump diaphragms have debris/scale built up.....that pump doesn't have an internal check valve just 4 pump diaphragms.Spec sheet/parts......LINK

If you have a whole house filter and it is getting plugged it will do the same thing. Easy..change the filter. If not...all the advice above is good. :) :)

I neglected to mention that I have found no evidence of any water leakage, at least nowhere I can get access to. But that does give me an idea to stop at a hardware store and buy a 1/2" MPT cap to put on the pump outlet and eliminate any chance of system leakage beyond the pump. There is no system filter, the tank is right next to the pump, I can see the entire 15" supply line, and the screen in the intake bowl is clear. So the problem will be in the pump itself.

Cycling Shurflo Smart Sensor pump | Good Sam Community

dbbls
Explorer
Jun 07, 2014
It sounds like you have a leak. If you can not find one in the plumbing it may be a leaking check valve in the pump.
ed6713
Explorer
Jun 07, 2014
dbbls wrote:
It sounds like you have a leak. If you can not find one in the plumbing it may be a leaking check valve in the pump.

As just said, you described a classic sign of a water leak. Time to trace out all water lines.
Old-Biscuit
Explorer III
Jun 07, 2014
You have a small leak.......could be at a fitting, could be toilet water valve, could be dripping faucets/shower head, could be drip at low point drains, could be dripping at 'city water' inlet check valve, could be water heater PRV weeping etc.

Could be pump diaphragms have debris/scale built up.....that pump doesn't have an internal check valve just 4 pump diaphragms.
Spec sheet/parts......LINK
Twomed
Explorer
Jun 07, 2014
If you have a whole house filter and it is getting plugged it will do the same thing. Easy..change the filter. If not...all the advice above is good. :) :)
StuartT
Explorer
Jun 07, 2014
I neglected to mention that I have found no evidence of any water leakage, at least nowhere I can get access to. But that does give me an idea to stop at a hardware store and buy a 1/2" MPT cap to put on the pump outlet and eliminate any chance of system leakage beyond the pump.

There is no system filter, the tank is right next to the pump, I can see the entire 15" supply line, and the screen in the intake bowl is clear. So the problem will be in the pump itself.
Dick_B
Explorer
Jun 07, 2014
Our shower valve was leaking a little and took some extra effort on the two handles to completely shut off the water.
larry_cad
Explorer II
Jun 08, 2014
I have occasionally placed a paper towel in the kitchen and bathroom sink to show the "stain" of a couple of drips. Sometimes a slow leak is hard to find.
flapbreaker
Explorer
Jun 08, 2014
I had a pump that had a bad internal valve. It would allow the water in the pipes to flow backwards through the pump. One easy fix is to buy a Shark Bite fitting (1/2 check valve) and install it on the water line exiting the pump. These fittings are super easy to install on pep pipe. You just cut a section out of the pipe and the fittings just push in. I found one at ACE hardware. They are also on amazon.
Old-Biscuit
Explorer III
Jun 08, 2014
In-line check valve on ump discharge will NOT stop pump from short cycling.
Pump pressure switch on pump senses discharge pressure. If pump internal check valve (on pumps that have one) is leaking, discharge pressure will still drop causing pump to come on and build pressure back up to shut-off set point.

The in-line will stop city water from flowing backwards into fresh water tank and overfilling it.

In-line check valve in pump suction line stops both....back flow and pump short cycle IF internal check valve is actually leaking.
flapbreaker
Explorer
Jun 08, 2014
Old-Biscuit wrote:
In-line check valve on ump discharge will NOT stop pump from short cycling.
Pump pressure switch on pump senses discharge pressure. If pump internal check valve (on pumps that have one) is leaking, discharge pressure will still drop causing pump to come on and build pressure back up to shut-off set point.

The in-line will stop city water from flowing backwards into fresh water tank and overfilling it.

In-line check valve in pump suction line stops both....back flow and pump short cycle IF internal check valve is actually leaking.

Ah, you are correct that it may not stop the pump from cycling as the pressure in the line between the pump and check valve could still drop if internal valve is bad but like you said it would prevent city water from flowing back into the fresh water tank.