750 foot deep well problems

[Jeffy82095]

What I know of the well it is about 750 feet deep and It was drilled in 2006. Currently has a 2 hp pump and has been supplying great water for us for over 10 years. I have been getting air into my house plumbing lines. All issues have started about 6 months after my neighbors house got struck by lightning. It blew out the start/run relay in my well pump control box. I replaced that and everything was great for about 6 months then the air issue started. I just got done pressuring testing the well supply line from the adapter to inside my house. No leaks it held pressure for 30 minutes. Seems what is happening is that when the well pump first starts it pushes air up the downpipe and into the house plumbing for the first minute or so,When the pressure switch opens and the pump shuts off there is a suction that is pulling the water back down into the well. I’m guessing a bad check valve or a hole in one of the downpipes. I had the well driller out that originally drilled and he quoted me $18,000.00 to pull and replace the pump,wire and pipe. The wire I’m sure is fine it’s running now. What is the correct pipe to install at that depth? Is a 2 hp pump enough? What about a constant pressure pump? Also 18 thousand seems high to me any help would be appreciated greatly.

 

[Valveman]

Yeah, sounds really high. Get another quote. A 7GS20 pump/motor can be had for 2K, even 3K from a driller would be a lot. another 3K for 6-4 wire if needed. But your wire is probably ok. Another 3K-4K for 1" galvanized pipe as I think that is a littel deep for PVC even sch 120, but you could check. I add up about $10K for materials at list price. Driller gets them a lot cheaper. So I think another 8K for labor is a bit much. But not too many pump guys set up to work with wells that deep, so you may not have much of an option, which is why it is 18K. Sorry.

A bad check valve on the pump would not let air in the lines. You will most likely find a hole in the galvanized pipe right where it screws into the brass or Stainless pump or check valve. A good pump man would know to wrap a foot or so of the pipe at the check valve with electric tape to keep electrolysis from eating a hole in the threads on the first galvanized pipe. Ask how much for just a pull and set and one joint of pipe as that is probably the only problem.

You can verify a hole in the drop pipe by removing or gutting the check valve at the tank. Without that check valve the pressure will bleed out the hole and the pressure will drop even though no water is being used. That is what you should be seeing as there should be no other check valve in the system except the one on the pump. I'll bet you have a check at the tank and maybe three more in the 750' of drop pipe. The books will tell you to install that many checks, but the book must have been written by the people who sell check valves. Extra check valves cause water hammer, and water hammer and/or electrolysis is what caused the hole in the drop pipe, and causes lots of other problems as well.

No, you do not want a "constant pressure pump". They will try to push that as a less expensive option with the three phase motor and smaller less expensive wire. and it is. But it will cause so many problems and need to be replaced expensively so many more times than a regular type pump that you will pay several times more in the long run.

One thing you might consider with such a deep well is using a cistern. With a cistern you could install a 1.5HP pump to get about 3-5 GPM. A 5GS15 would be less expensive and without working with a pressure tank might be possible to hand on Sch 120 PVC pipe, and of course smaller 8-4 wire. This would take a lot of wear off the deep set and expensive well pump. A cistern booster pump and a PK1A control kit would only cost maybe 1500 bucks and could be easily serviced at the surface and by yourself.

 

[Sponsor]

 

[Reach4]

I just got done pressuring testing the well supply line from the adapter to inside my house. No leaks it held pressure for 30 minutes. Seems what is happening is that when the well pump first starts it pushes air up the downpipe and into the house plumbing for the first minute or so,

1. May we assume there is an above-ground check valve, probably just before the pressure tank? If you did not, a small leak would cause the pump to cycle, but you would not be sucking in air etc.
2. When you say "adapter" I presume you mean the pitless adapter.
3. When you did that testing, did you replace the o-ring at the pitless adapter, and lube it properly? I am not saying that is your main leak, since a leak at the pitless is not likely to admit enough air into the system to tank take a minute to clear, unless the pipe between the pitless and the house were very long. Some people use "a minute" to represent months or more, but we know you are not doing that.