You are not logged in.

Dear visitor, welcome to SPRINKLER TALK FORUM - You Got Questions, We've Got Answers. If this is your first visit here, please read the Help. It explains how this page works. You must be registered before you can use all the page's features. Please use the registration form, to register here or read more information about the registration process. If you are already registered, please login here.


Tuesday, November 10th 2015, 9:09am

Rapid on-off cycling during off hours.

Pump is 10 years old, never had a problem and works actually fine. It has Hunter SRC Plus controller. Pump has small pressure tank installed. Recently I noticed that during off hours (when system should stay shut) every 10-15 minutes pump makes 3-5 very rapid on-off cycles. I assumed that problem might be related to aging pressure tank but I was not sure.
Tank has valve like on car wheel and I tried to measure pressure inside of tank with tire pressure gauge.
It is stated on tank that it was pre-charged to 20psi but gauge shown no pressure.
Any ideas what could be a cause for that rapid on-off cycling ?
I appreciate any suggestions in advance.


Supreme Member

Posts: 5,383

Location: Metro NYC


Tuesday, November 10th 2015, 9:54am

You should power down the pump and drain the pressure tank and prepare to add air if it is needed.

If you have a modern diaphragm/bladder type of tank, the air part is supposed to be separate from the water, and a check for this involves depressing the tiny plunger in the Schraeder air valve, and not seeing water come out. Make sure the air pressure in the tank is about 2 psi less than the cut-in pressure on the pump.

If you have an old-fashioned air tank, with air and water touching, you have to pressurize (same 2 psi differential) the whole tank with air, then turn the pump back on.


Tuesday, November 10th 2015, 11:48am

Tank model is Simer LT2. Installed horisontally

Rate this thread