Drain outdoor well tank for winter?

[Tom NJ]

This is my first year living in my bride’s house, which has a rain water system for watering the gardens. The system consists of a 1200 gallon tank, half buried in the ground, that is fed from roof rain run-off. Under the porch and exposed to winter temperatures is a pump, driven by an electric motor, that draws water from the tank and feeds it into a well tank (of the type used in house well water systems). From the well tank the water moves through a system of underground PVC pipes to the three gardens.

With winter coming I know I need to drain the pump and the underground pipes, but I’m not sure if I should drain the well tank. My concern is whether the diaphragm could be damaged by the well tank water freezing, or from the tank being empty. Any suggestions?

Thanks,

Tom NJ

 

[JC1]

How far underground is the tank? If it's 4 ft below ground that should be below the frost line.

 

[Pop_Rivit]

That sounds like a cistern, or modern day version of one. A lot depends upon the depth of the tank and the depth of the frost line. If it were mine here where the frost line is around 50-60 inches I'd drain the majority of the water from the tank.

 

[walterjay]

Completely drain the diaphragm tank. This is the correct method.

 

[daves87rs]

Originally Posted By: walterjay
Completely drain the diaphragm tank. This is the correct method.


+1

 

[HerrStig]

The old timers would cover a tank with straw, the heat the straw gave off as it decomposed kept the tank from freezing.

 

[bvance554]

What does your bride normally do with it in the winter?

 

[edwardh1]

how expensive are 1200 gallon tanks like that?

 

[Tom NJ]

I'm not worried about the 1200 gallon fiberglass tank that is partially underground. The tank is vented so freezing should not cause any problems. My concern is the well tank and whether draining could affect the diaphragm, e.g. cause it to dry out or crack. If not then I will drain the well tank.

The tank was installed by my bride's late husband who passed away in 2014, just three months after my loving wife also passed away. She happened to sit next to me in a pub last year and we got talking about the grief process and discovered we had everything in common. Her late husband found the tank for sale in the newspaper so I don't know exactly what he paid but I know it was only a few hundred dollars. Last year the pump was drained, not sure about the well tank. I started the system up again this year so this is my first winter with it.

 

[totegoat]

If in doubt, drain it. Amazing what a hard freeze can break.

 

[MNgopher]

Drain the tank. Only way to ensure nothing gets damaged by freezing water. Always surprising what ice can break...

 

[Fitter30]

if you drain the pump and piping blow it out with a air compressor to get all the water out.

 

[SHOZ]

You can fill the pump with the RV antifreeze.