Hoping for help with a mysterious problem, starved pumps or air in system?

[doublj70]

Hello All,
I have had a strange problem that has occurred several times over the last year that I can't figure out. I get to the wash in the morning, and several of the bays don't have any pressure, and maybe one is pulsating heavily, and a couple working properly. Then, after a few minutes, (sometimes I need to run the pump for like a full 4 minute cycle ) everything starts working normally. It always seems to happened in the early AM. Also, I have Mark VII pump stations which all the pumps get inlet water from a common manifold. I have narrowed it down in my mind to a couple possibilities. One is that I have an intermittant sticking air solenoid that stays open, and overnight when no one is washing, it pushes air back into that water supply manifold causing some type of air lock. My only other theory is the water softener is regenerating at some wierd time and somehow starving the pumps...
Has anyone else out there experienced something similar, or have any ideas on what it could be? Any advise would be greatly appreciated!

Sincerely,
John

 

[Whale of a Wash]

I would start at the one getting the most air, then see if it is related to a certain function or not. Do you have brass fittings like I used to that get eaten up by the soap. If so replace with plastic pushlock. Is there a back flow preventer on the water side sticking? I've also seen the soap and wax solenoids at the adjusting screw let air in . Does a hydrominder have low water in the tank, to exposing the exit side to air and then fill the tank while your washing and then disappear. Take a pad of paper with you and write down on each bay what is happening, and then you may see some correlation, as to what they have in common.

 

[mac]

I've seen this at some washes before and it can be baffeling. What I found most of the time was that it was caused by a faulty check valve near the head of the pump that gravity feeds from a tank. What happens is a customer selects a foaming low pressure product. Some of the foaming product goes back through the high pressure hose to the pump, back through the faulty check valve and into the manifold and tank. Then another pump can start and suck soap, which makes a lot of bubbles internally. To see if this is happening have someone turn on each bay on a low pressure foaming function for 3 or 3 minutes, while you look in the water holding tank. If you see anything coming in from the bottom fitting, there's your culprit. Also, it is most likelly not caused by the softener regenerating. Most of those when they regenerate just pass straight water through during that cycle.

 

[JGinther]

Does your water tank use a float valve or solenoid? Either one in different ways could be sticking for a while, allowing the pumps to suck air for a moment, especially if you have a float valve that has hot water plumbed to it. Do you use cold water rinse? If so, will it happen on rinse (pressure fed)? Also, if yours is the Mark VII type that uses a big pvc pipe to manifold to each bay, and your water level in the holding tank is not any higher than the pumps, a very small leak on the manifold piping will allow air in overnight. The latter is most likely. Try elevating all of your tanks if possible - unless you think you can find the air leak (very difficult with those type systems since they will not always leak water back out).

Good luck!

 

[JustClean]

I had exactly the same problem. I also have Mark7 Aqua Spray. It took me a while to figure it out. It is the non return valve from the hot water tank to the manifold. Mark7 uses valves with conical pistons inside and I believe they get stuck in the cone. I replaced all my check valves with flat pistons and never had a problem since. Cheers Justclean