Can't get new oil water heater to stop locking out.

2x_Tom

A couple weeks ago I replaced an oil fired water heater. He had an old John Wood 50gal with a Becket burner .75 70 degree nozzle. I put in a 32gallon Bock with the Carlin burner matched to it running a .6 60 degree hollow nozzle.

I don't work on oil equipment normally and wanted to do an indirect instead as the boiler has to maintain anyway (leaks when cold).  He wanted to go oil again with the understanding his oil company has to do the final tuneup on it. I put it in and did the limited setup I could. Zero smoke, you have to close the air shutter to about 15 to even get smoke. Factory sets it at 45 and doesn't want you to deviate more than five so I left it at 40. Draft is about -.25 to -.03 at the breach. 

This thing has been locking out seemingly randomly. Sometimes it will last a few days, other times it will be a day. Always fires right back up. Anytime I check it it's loaded with errors for lost flame (for which it will reset) and one or two for failure to ignite (when he has to push the button). Oil company came out, moved the shutter down to .35 and said everything is fine

I replaced the entire burner due to a defective air tube which was welded at the wrong position clocking the whole burner to about 1. That rules out any bad components. I can't figure out what the heck is going on with this new one that wasn't going on with the old one. The boiler right next to it runs just fine as well.

It's a two pipe oil setup (yes the plug is in).  1/2" lines run to the boiler from the underground tank about 70' away with 1/2 x 3/8 tees about 2' from the boiler for the water heater. The boiler has a Riello burner and a 1.0 nozzle. Ive sat there for an hour with this thing running and no issues. The boiler fires while the heater is running and vise verse, no issues. I've thought about putting a tiger loop on the water heater to try and rule out the boiler possibly pulling the oil from the water heater when it doesn't run for a long period. I feel like it would have to be bleed if that was the case and not fire right back up I also don't love the smoke pipe setup though the old heater ran fine with it. 

Here's a photo incase I'm missing something glaring here. 

HydronicMike

Is it failing to light or flaming out during the run cycle?

If it’s failing to light could be a vacuum leak or problem with the tank, but I would suspect the Riello to be more finicky and locking out over the Carlin.

If it’s flaming out, at what point of the run cycle is it doing it?

Did you try a vacuum gauge and see if the vacuum is increasing while running?

And what effect on vacuum with the boiler's burner off, then while running a long cycle.

I’d probably start off with an oil watcher on the line. Try to see if you can let it sit overnight and watch a first cold start up. As a first test I’d also increase the pre purge time.

I’d definitely ditch the two line and put a tiger loop on each burner.

What were the rest of your combustion numbers, especially excess air.

That’s not a b vent, is it? Is it in a chimney or up an exterior wall?

2x_Tom

Is it failing to light or flaming out during the run cycle?

Both. The button has to be hit when it fails to light (presumably multiple times to get to lockout). It's also full of errors for having flamed out and successfully relit.

If it’s failing to light could be a vacuum leak or problem with the tank, but I would suspect the Riello to be more finicky and locking out over the Carlin.

I agree. I'd also suspect the old Becket on the water heater would have had the same issue.  It's pretty much the same Suntech pump. 

If it’s flaming out, at what point of the run cycle is it doing it?

Unfortunately I can't recreate it. Every time I'm there it behaves perfectly. 

Did you try a vacuum gauge and see if the vacuum is increasing while running?

And what effect on vacuum with the boiler's burner off, then while running a long cycle.

I’d probably start off with an oil watcher on the line. Try to see if you can let it sit overnight and watch a first cold start up. As a first test I’d also increase the pre purge time.

I did not. I'm not really an oil guy but that makes sense to see if something is restricted. 

I’d definitely ditch the two line and put a tiger loop on each burner.

That's pretty much where I am right now. I'm running out of ideas that could be intermittent, not effect the other burner, not effect the new burner and not be the new burner itself.  I'm going to bring a camera or mirror next time I'm there so I can look into that combustion chamber and see if there's anything blocking it I can't see from the top. Though I can't imagine it would be intermittent if that was the case. 

What were the rest of your combustion numbers, especially excess air?

Im not bothered by the flue pipe arrangement

They unfortunately don't leave the results when they went. I don't have an analyzer so I'm just taking their word for it that it's right. They say there's nothing wrong with obviously there is though. I did try putting the air down to just over where it had zero smoke with the same results. 

EBEBRATT-Ed

Two burners on a two-pipe system is no good.

One burner pump will always be stronger than the other. One burner runs it pulls oil from the other. A separate suction line for each burner is the way to go. If you have little to no lift it might work but if you have lift you will have issues.

One thing you might try is to put a relay on the water heater. When the water heater starts you pull in a relay to shut down the boiler. Might help.

2x_Tom

https://forum.heatinghelp.com/discussion/comment/1874691#Comment_1874691

What perplexes me a bit is how in ran fine for 40 something years.

As far as lift goes it does pull from presumably the top of a buried tank. It runs about 45' along the basement wall, 5' up the basement wall and through the foundation. It then goes to an underground tank about 20' away.

Would the Tigerloop on just the water heater or both units help?

If it was the boiler pump messing with the heater pumps oil supply would it restart when the button is pushed or should it have to be bleed?

2x_Tom

I missed this. The boiler has a check valve on the inlet. I don't believe the old water heater had one though maybe I just didn't notice it and removed it. I did finally show up with it locked out and it cycled twice to get going. It also seems to be overnight that it happens

I'm leaning towards what Ed said about one sucking the other dry. It has to be an oil issue and it self purges after a couple cycles.

I'm throwing a tiger loop at it for now and hopefully that solves it. If not maybe the boiler needs one to so it becomes a one pipe system.

HVACNUT

Does Carlin spec a .60 GPH nozzle with the Bock 32E? I thought it was supposed to be a .75 GPH nozzle at 100 psi.

2x_Tom

https://forum.heatinghelp.com/discussion/comment/1874768#Comment_1874768

Yes they do. It used to be that. They changed it sometime in the last couple years. I went through that with Carlon on the phone. I initially thought it was the wrong burner because they said the same thing you did. Eventually they figured out it changed. It's now .6 at 155psi.
The Becket burner for the Bock 32 I believe is still the .7 or .75 at 100psi.

2x_Tom

So the tiger loop is on the water heater. Kind of interesting to watch it now. First pic is with the water heater running. Second pic is with the boiler and water heater running. You can watch the color change as the boiler cycles on and off.

Big Ed_4

The check valve is a tell-tail of that issue from the past .. They don't work and only adds restriction to make the issue even worse….

I would throw on a tiger loop and say good night…

EBEBRATT-Ed

The lower lighter colored picture looks like air in the oil to me.

No one in their right mind would ever install 2 burners on 1 suction line. You can check valve it, tiger loop it anything you want and in most cases, this is what you will get"

1. some jobs may run fine if your lucky
2. some jobs may have intermittent problems
3. some jobs won't work at all

A lot depends on the lift or lack of lift.

No two oil pumps are identical, no two burners have exactly the same pipe fitting resistance and the burners have different nozzles.

What do the nozzles have to do with it? The burner with the smaller nozzle sends more oil back the return line.

Its just one of those things that can't be predicted.

We used to run 2 suction and 1 common return for 2 burners. And that is what Suntec used to recommend.

2x_Tom

It certainly is air in the oil. Somehow it gets kicked up when the boiler runs.

It's clear the right job would be to run another line. So even putting a second tiger loop on the boiler and ditching the return would still give the opportunity for this to keep happening?

Really wish he just let me put in the darn indirect.

On another note. I found out the chimney liner went in right before the heater change. That 7" reduces down to 6" in the wall. They also capped the chimney with a ventilator for some reason.

2x_Tom

Just thinking out loud (or typing). Would it be a bad idea to turn the return line into a suction line and put a Tiger Loop & filter on? The only negative I can think of is hopefully they put it far enough into the tank.

HVACNUT

Fix the oil lines.