Long--well to tank is frozen

[vineyridge]

A well contractor replaced the 900 gallon pressure tank last fall. I've had this well for more than 30 years and in all that time it's never frozen before. The old setup had a gadget that expelled air when the pump turned off; it puffed air out of a device attached to the well head; this one doesn't do that. I've insulated all the pipes which are now PVC, not metal.

The system is not in a pump house. There are four houses on this well.

It froze two days ago, and I was told to run the frost free hydrant next to the tank to keep the pump running more often. That did not work.

Yesterday it froze, and I used a heat gun on the above ground pipes between the well and tank. Whether or not that melted ice or whether it just warmed up enough, I do not know, but the well got working for the whole day.

Last night it was completely frozen by 10:30. I'm now going out with the heat gun to see if that makes a difference.

We are supposed to have weather between 10 and 25 degrees for the next three days, so the well will undoubtedly freeze again, even if thawing works.

Is there some one way gadget that can allow water to go into the tank, but drain it back into the well when the pump turns off? Because as long as water is in the pipes between the well and the tank, it's going to freeze.

I do have a propane tank with a heater on top that I could drag out and aim at the well head, but that would use a huge amount of propane daily.

I've been in constant contact with the well man, but nothing seems to work.

I need help, other than a heat gun.

 

[Valveman]

A bleed back system has several little parts that need to work properly to drain the line. First there should be a bleeder orifice on a tee about 5' down the well. Then before the water goes into the pressure tank there should be a check valve with a Schrader valve on the inlet side. When the pump shuts off the check valve closes. The check valve closing takes the pressure off the bleeder and allows it to open. Then the water from the check valve to the bleeder should drain back into the well as air is let into the Schrader valve on the check (should not have a cap) When the pump comes on the pipe full of air gets pushed into the pressure tank. The Air Volume control (AVC) about half way up the tank lets out the excess air so it doesn't blow a glass out of your hand at the sink.

My guess is the check valve stopped working and the line no longer drains back.

 

[Valveman]

A 900 gallon pressure tank holds about 150 gallons of water. With a tank that size letting the water run is not going to prevent freezing. Even with a 2 GPM faucet running the tank will supply water for 75 minutes, which is long enough for the line to freeze up again.

If you can't get the lines deep enough to prevent freezing, a bleed back system with an old style galvanized tank is an option.

 

[vineyridge]

I was under the impression that a 900 gallon pressure tank held about 450 gallons of water.

I used the heat gun for almost an hour on metal and PVC pipes coming directly from the well head and it did nothing. I couldn't use it on the PVC going into the tank because of the insulation.

 

[Valveman]

Everybody thinks those big pressure tanks hold a lot of water. 25% water would be about max if you have the proper air charge. Normally about 10-15% of the total tank volume is used before the pump comes on. The water you get before the pump starts is called tank drawdown. That tank may hold 450 gallons, but most of that is wasted space as you can't get that much out without completely draining the tank.

 

[vineyridge]

The well man who installed the new pressure tank came yesterday. He says the well was fitted with a bleed back system which had obviously failed. He too believes that the check valve installed back in July or so has failed. So he installed an electric pipe insulating tape to keep the plumbing between the well and tank thawed and insulated the heck out of it as well. When things warm up, he will redo the plumbing that he put in in the summer.

Since this is the first cold weather we have had since the new tank was put in, it's impossible to determine when the check valve actually failed or even if it ever worked. It seems to me that that well parts are nowhere as long lived as formerly. There is a brass fitting with a 75psi pressure rating on the well head, and three of them have failed within hours of installation--one didn't even work when first installed.

 

[Valveman]

What do you mean the Pressure Relief Valves failed? That is rare.