Post de-winterization water issue

[mitch]

Finally it's warm enough to de-winterize the water system and everything looks good except one thing.  When I run the kitchen sink the pump is pulsing as opposed to staying on constantly.  When I flush the toilet or run the shower it comes on and stays on and the pressure is what I remember as normal.  The pressure at the kitchen sink is normal as well.  It's behaving as if the draw at the sink is just below the demand required to keep the pump on constantly.  I don't recall it doing that last year.  I checked the sink faucet strainer and there's no clog or restriction.  I'm a bit baffled.  Any ideas?

[tinkeringtechie]

[quote timestamp="1430235899" author="@mitch" source="/post/10102/thread"]Finally it's warm enough to de-winterize the water system and everything looks good except one thing.  When I run the kitchen sink the pump is pulsing as opposed to staying on constantly.  When I flush the toilet or run the shower it comes on and stays on and the pressure is what I remember as normal.  The pressure at the kitchen sink is normal as well.  It's behaving as if the draw at the sink is just below the demand required to keep the pump on constantly.  I don't recall it doing that last year.  I checked the sink faucet strainer and there's no clog or restriction.  I'm a bit baffled.  Any ideas?[/quote]How rapid is the pulsing? If it's very rapid (like a machine gun) then it can be something as simple as a trapped air bubble.

[mitch]

[quote timestamp="1430238896" author="@tinkeringtechie" source="/post/10104/thread"]

Finally it's warm enough to de-winterize the water system and everything looks good except one thing.  When I run the kitchen sink the pump is pulsing as opposed to staying on constantly.  When I flush the toilet or run the shower it comes on and stays on and the pressure is what I remember as normal.  The pressure at the kitchen sink is normal as well.  It's behaving as if the draw at the sink is just below the demand required to keep the pump on constantly.  I don't recall it doing that last year.  I checked the sink faucet strainer and there's no clog or restriction.  I'm a bit baffled.  Any ideas?

How rapid is the pulsing? If it's very rapid (like a machine gun) then it can be something as simple as a trapped air bubble.[/quote]It don't think it's that rapid, in the neighborhood of once every half second (using the very technically advanced one mississippi two mississippi method).  I would think an air bubble would clear out after a bit and I've been running the pump a lot over the last few hours as I sanitize.

[mitch]

I had a thought! My pump could be acting the way it always did except that right now I'm on shore power so the pump is at max voltage and therefore max flow and is able to produce slightly more then the kitchen faucet needs hence the cycle.  Usually I'm on battery so it's likely that I'm at slightly less voltage and the pump is turning a little slower so it runs continuously to keep up with the flow.

[charliem]

[font size="3"]Could well be. Pull the power cord and try on the battery.
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