My cb2800 won't start ... thoughts or ideas?

[ShopSpecialties]

I would stay with checking the basics first.

When you hit the reset see if it fires right up then go to watching oil pressure and flame. Check for oil gauge bounce and make sure the flame has no sparkles. Sparkles is bad oil/water/antifreeze. I am thinking you still might be sucking some air.

[gte]

Here is a video (at the bottom) of me starting it for the very first time. I also took some measurements with Dc, Ac and resistance on the CAD sensor. I'm going to go check on it in an hour. Does anything look off to you? I know you can't see it in the video, but the oil goes up to about 7psi and then settles at 4.5 or 5psi within a few seconds.

Before start, not running resistance


Before start not running - Dc


Before start not running - Ac


Running - resistance


Running - Dc


Running - Ac





Cleanburn start up after failure1: http://youtu.be/jZSPPxSX2xg

[ShopSpecialties]

Looks like it started nice and easy. Hopefully when it acts up you will be standing there and see what happens.

[gte]

Ok, well I will have to redo the low pressure and high pressure lines soon to rule that out. I also forgot to mention that I did not see any sparkling in the flame. I may have to set up a recorder to view when it stalls out?

[ShopSpecialties]

A camera would be a great idea since it will probably not fail if you are sitting there staring at it. I should get myself a GoPro for symptoms like this. 

[gte]

Good news, it kind of failed when I was sitting there. After the thermostat turned it off, I put volt meters on the solenoids and the oil pump junction box wiring and upped the temperature and it did the behavior seen in the first video, then I was able to see something even more interesting in the second video.

I noticed the air pressure gauge was showing pressure but the oil pressure gauge was not. The oil solenoid was however getting 110vAc and so was the oil pump. The unit would of course turn itself off after 5 or 10 seconds as it wasn't seeing a flame via the CAD sensor and this appears to be because there is no oil pressure.

During the second video, you can see me reset the unit a second time around the 20 second mark and then you'll see that there is no oil pressure or flame, then I go over to the pump to show there is voltage to it and right at the 28 second mark you'll hear a click or thump from the oil pump and then you can hear the unit turn on and then hear the normal flame whistle coming from inside of the fire box. To put it another way, the brain energized the pump but the pump did not turn on and there was no oil pressure and towards the very end of the window of time it will continue to attempt to start a flame/fire, the pump made a click/thump, turned on and created oil pressure, allowing the flame to start and the CAD sensor to see the flame and then allow it to continue to run as normal. Also, when the pump is creating 0 pressure, I can feel it vibrating slightly.

So I believe it is the pump that is the cause of it not restarting. I believe the unit itself tries to restart, but gets no oil pressure within the time allotment window that the brain allows for it to start and then goes into a failed limp mode requiring a reset button press to restart. So then the question that comes to mind is, could this be due to some sort of air build up in the pump/lines, or more likely (because of the click/thump clue) is there some sort of solenoid or relay inside the pump that is failing, which starts/turns the motor over therefore creating pressure? Is this common? What's a new pump cost? (do I even want to know)

Cleanburn start up after failure 2: http://youtu.be/P3lY6T632LE

Cleanburn start up after failure 3: http://youtu.be/A_VSk3LHiRo

[ShopSpecialties]

The first thing I would look at is the pump coupler. Sometimes one of the set screws will loosen up and it will not always spin the pump shaft. 

Has the reset ever popped on the pump motor ?

[gte]

I have never had to reset that button on the pump. How much disassembly is required to get to the set screw?

[ShopSpecialties]

With the way you have the pump mounted it would probably be the easiest to use an inspection mirror. Hold the mirror underneath between the motor and pump. The coupler will have a set screw on each end. Make sure they are tight on the flats of each shaft.

[gte]

Hi,

The set screws appear to be tight. It's behaving just like a starter that is on its way out, the coils get energized but it won't rotate until you smack it a little.

Can these pumps be rebuilt or am I better off buying another one?

Here is the latest pattern, that seems to be very consistent. I will go into the building and see that the unit is not running and hasn't been running for some time as the temperature is lower than the thermostat should allow it to be. I can tell how long it hasn't ran for based on how much lower the temperature is compared to where it should be. I will try to start the unit, and it will not generate oil pressure so before the run time window ends I will smack the case of the motor and it will start to rotate and create pressure and run after this. Depending on how long it has been sitting without running depends on how many times it will stall out before running on its own. It can stall out anywhere from 0 to 5 times. I attribute this to air in the lines when the pump is not running but the unit is trying to start its flame.

You can hear it sputter a little and then it will usually flame out, even though oil pressure stays in the 4 to 5 psi range on the gauge. Is the gauge slow to react with some sort of hysteresis? Do you agree that the unit can flame out due to a lack of oil or oil pressure, even if the gauge is reading 4 or 5 psi? Could the gauge be reading the pressure of the air inside of the oil lines and not know the difference, so it appears there is oil pressure there when it is really air pressure at some points mixed in, which causes flame out?

[ShopSpecialties]

Sounds like the motor is going bad. The motor and pump are 2 separate components that can purchased separately. The motor is a very common oil burner motor that is easily found many places and for usually under $ 100.

Yes, you can have small pockets of air all through out the system where the gauge reads ok sometimes and sometimes not. Air is a very big PITA.

If you are going to change the motor that would be a good time to replumb it since you have to take it all apart. 

[gte]

Will do, I did not know you could get the motor separate from the pump assembly, that'd be great! All of my google searches turned up the whole assembly and not the motor separately.

I will do the motor and replumb at the same time and hopefully have permanent success after that.

Is this the motor?

http://www.wasteoilheaterparts.com/110hpburnermotor33175.aspx

[ShopSpecialties]

That motor is for the metered pump.

The best thing to do is search by the sticker that is on the motor.

AO Smith EL2014V1 and you can cross reference this to other brands or just punch it into Google and see many places to buy it.

[gte]

Ok, lots of hits on that. When I get home I will check the sticker, confirm and then get a pump and start drawing how I can replumb this.

Thank you

[gte]

Some strangeness continues

I went out to start her this morning with a reset and she started but the flame looked weird and was 1/2 the length it normally is. It stayed that way for about 2 minutes, which is also uncharacteristic, but the pressure stayed the same. Then it went out and would not start after 5 or 10 resets, although pressure was climbing and the oil pump was working and I verified that oil was spraying as well as air. At this point, I figured I had oil and air, the only thing missing was spark. I pulled the boiler out enough to get a map gas torch flame inline with the oil coming out and it lit but then went out, then it lit again and went out and then it lit stronger and continued? I don't know if the oil had junk in it or if my electrode is on its way out. Now it seems to be starting normally???

Here is my pump sticker

AO SMITH Motor 316P717

Looks  like the number you supplied is a good replacement for it ... looks like this seller is out near you, do you know them?

http://www.ebay.com/itm/NEW-AO-Smith-Reversible-Motor-316P717-1-6-HP-1725-RPM-115V-XEL2014-FREE-SHIPPING-/261723416661