I am 99% certain that the fuel oil pump I just installed (Suntec A2VA-7116) is faulty. Have I missed something re:diagnosing the fault? I am a well coached DIY'er with 5 years experience maintaining this system.

To replace a seized Sid Harvey P4-91R pump, I installed a new out-of-box Suntec A2VA-7116 unit that I picked up from a local HVAC supplier.

With the new AV2V-7116 pump completely installed (no leaks), when started it produces zero output pressure. Using a compound pressure test gage, I tested the output side of the pump=0 psi, and the vacuum side=35-40 psi. Positive pressure on the vacuum side is not a good sign, correct?

The input/filter housing shows no oil has entered and the inline cannister felt filter is new and clean.

 

It sounds like the readings should be opposite from each other. PSI should be on the output side. Vacuum is measured in inches of water not PSI. At least that's what I was taught.

 

No way should you have pressure on the inlet side. I can't believe your gauge is right because if there was that much pressure, you would have blown the shaft seal & had oil running everywhere. You did bleed the air via the bleed port, did you not?

 

My terminology was incorrect - the output side read zero psi. The gauge port on the top of the pump read 35-40 psi.
Since posting I have installed another pump and have the system up and running.

 

Glad you got things up & running. Very rare to have a bad pump out of the box but, like anything else,
I guess it can happen. Hope the supplier didn't give you any trouble.

 

Hey Grady, well, I'm back at it. As of last night the pump I installed 30 days ago has seized! It worked flawlessly for 30 days. I'll be checking back with the reseller for warranty terms...

I was able to find, pick-up and install a replacement pump, same model, and install it. I tested the output before doing the final connection and confirmed pressure of 100 psi.
When called for heat the system started and cycled once and performed as it should. The next time it cycled, the burner began to sputter and by the time that cycle was complete the burner had almost gone completely out. I tested for pressure a second time and the gauge read "0", no pressure.
I have a 2 pipe system and the bypass plug was installed, new filter and nozzle, strainer, etc.
All I can come up with a is a faulty reconditioned pump.
Any thoughts?

 

Wow!! I can't believe your luck with fuel pumps. Was the 30 day old pump new or reman? I won't use reman pumps except the J model. Just too much bad luck with them.

Have you confirmed the coupling is in good shape & the proper length?
The symptoms you've had make me think maybe the coupling is slipping. Whenever I replace either a motor or a pump, I replace the coupling as well. It's just one of my many quirks.

No water? No solvents in the fuel?

Can you post a few pictures of the tank & piping all the way from tank to burner?

 

I hate to bring this up, if your tank is outside, you may have a gelling issue.
Could have a blocked pick up line too. Blow the oil line back.

 

You can learn a lot about Tigerloop here: Tigerloop
I'm a firm believer & have one on my own system.

Sorry, wrong thread but might still be worth looking at.

 

I'll check the coupling - that is a piece of the puzzle I have not addressed.
I'm also thinking that maybe, just maybe, I have a very minor leak on the input side - I pipe doped the fittings as I would normally do, but...
This pump cost me $50, and I presume it's remanufactured = headaches as you suggest...

 

The pump I prefer is the Suntec A2VA-3006. It has both an internal cutoff as well as an external solenoid.

 

Note to self, if a deal sounds to good to be real it probably is. I got my hands on another pump (new) and installed it - the system is back online, running perfectly (still haven't done a smoke test though...). The pump I picked up yesterday was either a poorly remanufactured one or someone had returned it faulty. Either way, for $50 it seemed too good to be real... I'll be making myself known back to the seller and returning the original pump. Thanks again for the support. Cheers

 

Fifty bucks for a pump?? Sounds fishy to me. Hope you checked/replaced that coupling. Cheap insurance. Good Luck. You're due for some.