Hitachi pump gx series

[fry30]

Hi everyone,

 

Could anyone tell me where is the screw to adjust on this pressure switch?

[fry30]

there is another screw, both visible screws are fully tight

 

[wayned]

I suspect that it under the glob of blue Locktite since it has been adjusted at the factory and is not meant to be reset!

[fry30]

Thanks Wayned, the pump run with short cycles, I read that the fastest solution was to mess with this screw...

[Crossy]

8 minutes ago, fry30 said:

Thanks Wayned, the pump run with short cycles, I read that the fastest solution was to mess with this screw...

If it is short-cycling it's invariably a waterlogged pressure tank. Drain the tank to re-establish the air cushion and you should be good to go.

[wayned]

I agree with above, don't mess with the screw.  The tank should have a drain plug on it.  Remove it and drain all of the water from the tank and put in back in and turn the pump on.  Before you remove the plug you should turn off the pump and relieve the pressure by opening a faucet otherwise the plug could become a missile when you loosen it!  It's a common problem with these pumps and is easy to fix as long as it is installed in an area where it is easy to drain.

[fry30]

I did this several times already, it usually improves it a bit but this time it does nothing

[fry30]

this time I tried to adjust the screw with a hex key, half turn clockwise, I heard a pop from the bladder and still the same short cycle

[fry30]

9030.t.mp4

 

 

[wayned]

What is the complete part number of your pump?  It looks like a constant pressure pump , I expected to see one with a large accumulator tank.

[fry30]

[fry30]

the water tank is outside

[wayned]

Your pump is a constant pressure pump, not what I expected to see.  I expected to see what is in the picture which is also a GX series pump but has a large accumulator tank which the pump sits on top of, not a small one like yours.  When I suggested "draining the tank", I meant the tank which is part of the pump not the big tank which is on the input and has nothing to do with your problem.  I think that Crossy thought the same.

 

I have repaired many of the above type pumps but have absolutely zero experience on the constant pressure ones.  Your problem might be a ruptured bladder in the small accumulator tank but it's just a guess.  Hopefully someone will be along that has some experience with this type of pump. Sorry  I can't be of more help.

!

[fry30]

Thank you very much Wayned, I bought this pump 2 or 3 years ago and I think it has always being on short cycle, however one time I connected it directly to the main water line, without the tank and the cycle was constant. Also when I open 3 faucets at the same time there is no short cycle.

[Daffy D]

Don't mess with the adjusting screws

 

You need to replace the bladder tank:-

Easy to replace, just unscrew it.

 

As a short term measure take it off and shake out all the water before replacing, this will solve the problem for short time.

 

 

[Crossy]

Yes, it looks like a constant-pressure pump.

 

Remove and shake the water out of the bladder tank, but I suspect the flow switch (marked "life save unit" on Daffy D's drawing) could be stuck or defective.

 

Time to get a pump guy in if you're not the DIY type.

 

[fry30]

where could I find a bladder tank? global house or home pro? is it possible to order on internet?

regarding the pump guy I read that most of the time they are just messing with the pressure switch screw.

[Daffy D]

 

1 hour ago, fry30 said:

where could I find a bladder tank? global house or home pro?

You can try any of those mega stores and /or any shop that looks like it might have water stuff. If they don't have they might point you in the right direction.

 

I got mine from the local shop that has everything, which surprised me as I only went in there to ask where I could get one and they had it in stock

 

It usually makes life easier if you take a photo of the pump model and bladder tank with you.

 

 

[wayned]

You can order from these guys: [email protected] .  Tell them the model number of the pump and ask them to send you an IPL.  You can pay via bank transfer and delivery by EMS.   PM me if the email address if deleted by one of the wizards in charge.

[fry30]

Thank you, I will contact them at least to know the price but I will try with the pump connected directly to the main line, last time it was running continuously, could it be a problem about the pressure from the tank?

[Crossy]

On 11/6/2017 at 7:09 PM, fry30 said:

I will try with the pump connected directly to the main line

You do realise this is illegal and a potential health hazard don't you?

 

Have you checked the flow switch yet?

 

[CGW]

On 11/6/2017 at 7:09 PM, fry30 said:

Thank you, I will contact them at least to know the price but I will try with the pump connected directly to the main line, last time it was running continuously, could it be a problem about the pressure from the tank?

If the pump is "starved" meaning it is not getting any water to pump, it will run constantly so what will connecting it to the mains prove?

[fry30]

I mean to connect it directly to the water line without using my tank. Strangely the pump is running normally now, without touching anything and when using the garden hose which is 40m far from the pump it run constantly. It could be due to some leakages on the water line. I will reinstall the tank and glue the pipes properly and see.

[Crossy]

45 minutes ago, fry30 said:

I mean to connect it directly to the water line without using my tank.

Have you actually read any of the responses to this thread?

 

[fry30]

19 hours ago, CGW said:

If the pump is "starved" meaning it is not getting any water to pump, it will run constantly so what will connecting it to the mains prove?

The water pressure was stable and the pump was running with long or constant cycles. I connected the pump directly to the water line because I needed to move the tank, strangely it was running smoothly so I'm wondering if the problem could come from the pressure or leakages.

[CGW]

14 minutes ago, fry30 said:

pressure or leakages

You don't think it could be the bladder tank is ruptured do you? 

[fry30]

if it was the bladder tank why would it run smoothly now?

I brought it to a shop to replace it and the technician working there told me that the bladder was probably fine and I should look into leakages instead.

 

[Crossy]

If you've moved it and it now runs fine - a stuck flow switch (now unstuck) is a prime candidate.