I have a well system. Recently my Subdrive 150 fan runs constantly. I read possible causes and eliminated two.

1. I shut off main water valve after tank, subdrive and pressure valve. This eliminated possibility of a water leak causing this.

2. I shut off well pump then opened faucet to relieve all pressure. I then checked the preload pressure on the tank and it was 35lbs which is what is called for.

So, what else could cause my Subdrive 150 fan to run constantly?

Thanks,

Gary

What does your pressure gauge read?

There are four possible culprits: 1. defective switch. 2. pump getting weak. 3. Falling water table causing problems. 4. A leak in the wellpipe which prevents the pump from pumping up to shutoff pressure.

Looking at the pressure gauge is step one. If the charge on your tank is indeed supposed to be 35#, then your pump should be cutting on at 37# and cutting off at somewhere around 57#. Is that the case? And if it should cut off at 57, is the gauge showing something less than 57?

The pressure sensor is set to 50# which is factory default.

I suspected a faulty pressure sensor so I disconnected one of the leads. The Subdrive then shut off.

So even though the pressure was getting to 50#, it isn't signalling a shut down.

I can't seem to find anywhere that sells this part yet. So, I tried adjusting the pressure down to 45# and now it is functioning properly. It runs to get the pressure up to 45# then shuts off. I tried moving the setting back to 50# and it never shut down just like it started several days ago. I am guessing the sensor is worn out.

So.. anyone know where one can order online a Franklin pressure sensor kit. Part # 223995901

Thanks

This is the Franklin site. Try them:

Contact Us | Franklin Electric E-Link

I am guessing the pump, for some reason, cannot get up to 50#, but it might very well be the sensor.

Ignore the post above. Having done a little research on your system, a subdrive 150 is a constant pressure system. When water is being used, it adjusts the pump speed to keep the pressure at a preset level. I have no experience with them. I'd call Franklin if I was you. Here are the contact numbers:

AUSTRALIA / NEW ZEALAND
Franklin Electric (Australia) Pty. Ltd.
106-110 Micro Circuit
Dandenong South, Victoria 3175
Australia
Toll Free: 1300 FRANKLIN
1300 372 655
Fax: +61 3 9799 5050
Tel: +61 3 9799 5000
Home - Franklin Electric Australia

UNITED STATES
Franklin Electric Co. Inc.
400 E. Spring Street, Bluffton, IN 46714 USA
Tel: +1.260.824.2900 Fax: +1.260.824.2909