Is my experience normal or just bad luck?

[Trey302]

So I've had my DOS & DDR for just under 2 months. Right out the the box the left pump head would not stay firmly attached to the DOS unit. It would stay in for a little while but eventually pop out causing it not to dose anything. Switching the heads did not seem to alleviate the problem so Neptune sent me a replacement unit. First one was also really loud once I got the new unit and realized how quiet it should be. I've had the new one for about 3 weeks now and about once a week the left side pump is losing prime. I notice I'm getting tiny bubbles in the line when priming it so they advised me to super glue where the plastic tube meets the bottom of the connector you attach the rubber tubing to. While I was working on that I submerged the tube in the cylinder like they said to see if it lost its prime that way. It held fine for about a day but eventually lost it again even with the tube still submerged so I assume this means something is wrong the the pump head. I see that was a common issue on the older units but not supposed to be on the newer ones. I'm waiting to hear back from Neptune to see what they say. I guess I'm just wondering if this is a normal experience with these units. I love it when it works properly but in less than 2 months of owning it I've already had what I would consider 2 major problems with it. Anyone else have problems like this or have I just been really unlucky?

[stre1026]

I've had a DOS that I've been using for auto water changes for about a year now. The only problem I had with my unit and was a common issue on the first units was a cracked head. Once Neptune replaced the head, it's been perfect. What type of tubing are you using for your unit? I'm wondering if it's not fitting on the head correctly so you're getting air sucked in when it's on causing you to lose prime? I'm using about 20 ft of plastic ice maker tubing all the way to my basement from my first floor and it's working perfectly.

[Trey302]

I'm using the tubing that came with the DOS. I've got some of the hard tubing that came with my old BRS dosing pumps but I haven't tried it yet. I tried everything they suggested to compare both sides and the tubing seems to be seating in the fitting properly from what I can tell. That's when they suggested super gluing the fitting from underneath where the hard tube and fitting meet. Problem is it also lost prime with the tube submerged directly into my alkalinity additive so it won't hold prime even when I bypass the fitting on the DDR. All this just makes me wonder if the pump head isn't holding prime and the fitting is causing air to get through as well. Neptune responded and are sending me a new pump head so I'll try that and maybe try using the hard tubing and see if that helps.

[lilu]

I have a similar experience - DOS arrived with the left pump head broken, returned to Neptune for repair. Now the right pump head won't prime, it's one problem after another with this unit.