2-Way Leaking Solenoid Valve

You should really watch this: Solenoid Valve How It Works

Weak coil or bad seal come to mind. Is your valve NO or NC?

Is inlet pressure too high for your valve?

The P/N and brand of valve would help too. There are a billion variants of valves.

NO means "Normally Open" - so it would need to be energized to close. Think yours must be Normally Closed, otherwise the tank would overflow if the power failed.

Just checked your link. My comment about the spool doesn't apply (there isn't one!) - but it could still be deposits building up on the disc or seat. Could also be a weak spring. Probably not the coil, as it's de-energized to close.

Has the flow direction been observed? It may be on backward. Also check the valve face and its seat for cracks or burrs.

If this valve cycles a lot the spring though intact could still be bad from fatigue. If you can shut the water off from another source the turn it back on the pressure of the water should seat the valve. If it stop leaking then the spring is bad.

Thanks ozzb!

I am thinking I'm going to replace the spring first and see it will fix the problem.

That NO/NC stuff was a test, sorta. Normally open and normally closed. When de-energized is the valve normally open or normally closed?

Your valve is NC so all that is holding it closed is the spring pressure. The coil is doing no work.

You should be able to get coils, if that's what you need.

Just hang around for awhile, someone who really knows about these things will come along. My experience is limited in this area.

Good luck.

Sounds like it is NC (normally closed), ie energized to open.

Check the seal/disc for scoring, cracking, crazing or build up of residue.

Check the seat for scoring or build up of residue.

Could be a weak coil, but when they go they usually go completely.

Is it connected the right way around?

Has the problem appeared suddenly, or got worse over time?

I don't know when the problem started but it has been like that for over 3 months, since I started maintaining the area. The way it was always done was by shutting off the water supply so the tank would not overfill, basically trying to avoid fixing the problem. It started getting on my nerves so I want to fix the problem and let the solenoid do its job.

The way it is connected is the OUT is going into the water tank and IN is connected to the water source.

Like you suggested I will try checking for any signs of residue build up and any cracking or scoring.

Thanks for the suggestions Holzfeller!

I believe in fixing things but I suggest you replace the whole thing. You have probably spent more time at work than the valve is worth.

What's the water like? If there are lots of dissolved solids they could be precipitating out and affecting the valve spool movement so it's not shutting off properly.

That could also be very well the problem because the filter hasn't been changed for a while...trying to save money as usual. The dissolved solids of the water source though are usually below 350 ppm. When I took apart the valve the spring was in OK shape, but like you said it could jam up the mechanism. I'll try taking it apart and cleaning out any precipitating solids. Thanks for input, I didn't think of that one.

Also, your valve may not be rated to operate under the pressure of your water supply. This could keep it from closing in it's de-energized state. If this is the case get a bigger valve or consider using a pressure regulating valve before the solenoid valve to lower the incoming pressure. While you've got the pipe apart stick a filter in there too.

Hi RDGRNR,

This is the spec for the valve http://www.ascovalve.com/ 8210R2. I can't really tell the pressure that it is rated for, but I think it says 100 and the inlet pressure for my valve is at 83 psi. I already have a filter but it has to get changed. I will try changing the spring first because I think it could be why the water is still coming in when the valve is de-energized.

P.S. the catalog number of the valve is 8210G002.

It looks like your valve is rated 100psi with DC and 150psi with AC, so either way you should be OK. If you are checking the seal/disc, note that there could be cracking that is invisible to the naked eye unless you bend or stretch it, but still enough to allow it to leak. If you're changing the spring you should change the seal/disc aswell. This is the part that usually goes first, it might already be on it's way out, and it would at least save you having to do it again later.

Good advice. 80PSI can open up some very small cracks or rough spots.

I'd suggest to the OP that he replace as much as he can afford.

I will not be around for a few days. I'm going to the "little house on the prairie", where there is no internet, nor cell phone service.

Cheers all.

We use quite a number of this style of valve here, and the main failure mode is the rubber diaphragm in the valve. A new valve should only be 100-200 Dollars. The old valve body can be left in place if the seat is in good condition. Just undo the 4 bolts on the top half of the valves and swap the new top to the old base. The old coil can be reused as well. Just pop off the red cap slide the nameplate to the side and lift off the coil assy. Make sure you keep a spring under the coil. Then place the old coil assy. on the new valve top. That way you don't have to do any wiring. Save the old good parts as spares. You can be in and out in 10 minutes, no plumbing and no wiring.

I forgot to mention that you need to shut the water off first because when you remove the top half of the valve there is nothing to stop the water flow.

Good luck.

I replaced the bottom part of the valve after finding a spare solenoid valve that had a blown coil on it. The valve seems to be working perfectly now!!!!!!!!!!

Thank you everyone for your help

Alright! That's why I hang out here.

Welcome timakachev, I expect to see you here when I get back.

I'm off to the airport.

The valve maybe leaking through as the seats, maybe worn or possibly the stops on the valve are not set correctly. If the valve in the past has worked properly and now has just started giving you problems this could be from normal wear or something has moved. It sometimes can be difficult to see if a valve in line is shutting off 100 percent but there are tests, such as Bench Mark that can perform preliminary tests to assure synopsis. Taking the valve out to make sure it is bubble tight, class six shutoff is the best way to see 100 percent but I understand sometimes this can not be possible. Preliminaries before taking out valve can be accomplished by visually looking at the valve make sure no bolts have come loose or any other parts of the valve may have moved. If this is controlled by a positioner you would need to check this to but from what i am hearing the valve is a on/off valve controlled by a solenoid. good luck

Hi timakachev,

I understand your problem is already fixed but here's a suggestion anyway: 83 psi is a fairly strong flow to stop all at once so I would consider adding a sealed "air column" in the system to reduce the water-hammer effect and therefore reducing the stress on the valve and piping. Could save you problems in the future...

Cheers,

Rick.

edit: ...fairly strong flow to stop all at once ... I meant pressure..