we have a heated pump house, supply lines to nearby wet areas are insulated, cottage is kept at 10deg when we are not there. Supply line from well (30' away) is not less than 48" below grade and has never frozen in 20 years since last complete re'n're. Two weeks ago I was there to start a kitchen and bathroom makeover. Nothing serious, no major changes to existing plumbing supply or drain. A bit of demolition and cut and cap plumbing to get started. Then out of nowhere I realized the pump was running over and over. I went to the pump house to investigate. No obvious pipe bursts or water present where it should not be. The pump would pressurize the system to 60psi then turn off. Immediately you could hear (and feel) a "whoosh" sound of water rapidly escaping from the pump body back towards the well. The pressure would drop to around 17psi (atmospheric) and then the pump would be triggered back on. I figured it was the foot valve. Fairly straight foreward fix except one thing... The well cap was completely frozen solid and I could not access the well or any plumbing within. Replacing the foot valve would have to wait. Considering that I was given a tight timeline (from my wife) to complete renovation before summer season starts I needed to forge ahead. I would keep the main shutoff valve closed and kill power to the pump when not in use. This way I could preserve the pump's prime and turn the system on whenever I reqd water to clean painting tools, wash dishes, flush the toilet etc. Worked great. Then on the last night of the past weekend I forgot to shut the main valve before I killed power to the pump. In the middle of the night I had to visit the bathroom to piss. Without thinking I flushed the tank and returned to my slumber. The tank fill valve was wide open with no water supply. Air was free to enter and let gravity do the rest. Furthermore the failed foot valve allowed the entire system to drain all the way back to the well head. Now I have a frozen well cap preventing me from addressing what I believe is the primary problem, the faulty foot valve. A friend suggested I build a small fire on the concrete well cover to heat/melt the ice that is preventing me from opening the cap. Good idea, no? This foot valve is not typically or smartly installed for easy access. Last time (15years ago) I had to submerge myself in near freezing water (mid summer) to disconnect the coupling that was securing the downpipe and foot valve from an easy removal. So here I go. April 14 2018. Down down down. Lucky I have a bit more natural padding and a wet suit to boot. Still not going to be fun. If, after all this it turns out to be the bladder in the pressure tank that failed instead, I'm afraid I might do something drastic. If if anyone sees an obviously glaring flaw in my deduction or plan pls let me know before it's too late.

I know nothing about irrigation except for what I've read here over the last hour or so. It looks as though I need to replace the check valve on my system since it loses its prime as soon as it shuts down. I'm attaching a picture of my set up. I'd like to know if there's any way to just unscrew the check valve and replace it or am I going to have to cut it out? I hope this is enough information. Thank you for your help! [ATTACH]91966[/ATTACH]