intermittent problem

Mikeman

About 2 weeks I noticed the room temperatures had dropped. I went to the basement and my Energy Kinetics boiler had shut down with a red light on the burner primary control. I reset the unit and while running it seemed like the temperature reading on the temp & pressure gauge above my aquastat was not dropping. I thought that perhaps the circulator was not moving water as usually after the boiler has not run for a while, the cooler water returning to the boiler causes the temp to fall. It eventually kicked out again. At that point I called my boiler service guy. By the time he got here things had cooled down some. He reset the burner control and it started and ran just fine the whole time he was here. Thinking it may have been a fluke, we decided to do nothing for the moment. The boiler ran without shutting off for about 8-10 days. Then I noticed I could hear it short cycling off and on about 4 or 5 times in a 10-20 second period of time and then would run fine. Eventually it started kicking out again more frequently. Thinking perhaps the cad cell was failing, I replaced it with a spare I had on hand. That changed nothing. Yesterday I sat by the boiler and watched it operate. The burner was turning off at the aquastat high limit and turning back on when the temperature dropped below the 135 degree low limit. The circulator was cycling off and on per the low limit settings. I used my mechanics stethoscope to listen to the aquastat and had a good distinct click at all the correct temperatures but then I noticed that when the burner kicked back on at the low end, it would raise the temperature to 135-140 degrees and then the burner would short cycle a few times and then go back to normal operation. Eventually over a few hours it locked out again a few times. The circulator seems to be moving water just fine as I am getting hot water to all zones and returning temps were rising. The boiler ran all night last night and all day today and is still running on demand. I have not detected any short cycling when I've been in the basement and all zones are being satisfied. I'm wondering what is going on because of the intermittent nature of the problem. I am thinking some switch in the burner primary control may be starting to fail. Does anybody have any good ideas?

mattmia2

Did the tech check combustion and draft and oil pressure and flame pattern?

Mikeman

No he didn't. He just did the annual service on December 22 and it has been running fine since then. He had run over in the evening to make sure I had heat and at the time all seemed fine. The fact that it was running fine the whole time he was here lead me to figure we had a fluke situation. It did run just fine for over a week after that, so I really quit worrying about it until it acted up again. I wanted to have some symptom information in case I called him back and the darn thing was running fine again when he got here. At this point I'm intrigued, as I have never had an intermittent issue with this boiler before. I guess it could be a pump coupler that slips a while and then grabs. That could change the fuel volume but I don't know if they even fail intermittently. We are supposed to be in the 70s the next couple days so I'll hold off on a weekend service call and call him Monday. Is it common to have intermittent problems?

mattmia2

It could be something is just on the edge of burning properly then wind or outdoor temp changes or another appliance operating or something changes the conditions so it doesn't burn properly. Could be dirt or water in the fuel or a clogged fuel filter or line. Could be a failing ignition transformer. Measuring resistance usually shows that. Could be a control problem although I think that would stop the motor. Figuring out if it is fuel or ignition or draf when it is happening could narrow it down.

EBEBRATT-Ed

Yes intermittent problems are common.

When you have to reset the burner control which you did that means you have a burner problem or a cad cell/control problem, ignition problem or oil supply problem

Mikeman

A few years ago the boiler shut down and the technician determined the motor to pump coupler had stripped out thus stopping the fuel supply. The guy has told me that even though it was working fine, eventually we should replace the Danfoss 071H2003 oil pump because it is now obsolete and strainers are no longer available. On the bright side the boiler has been operating just fine, without a hiccup, for about 34 hours. After going through other posted topics, I now realize what the EK unit has a puff switch and how a draft issue or air supply issue could cause this type problem. The more doodads they add, the more chance for marginal conditions that could cause an intermittent problem. For anybody else interested here is an EK link. https://energykinetics.com/wp-content/uploads/2015/10/solvingIntermittentLockoutsRelatedToInsufficient.pdf Thanks for the advice folks. It's always good to have some understanding of how any control system operates. Every time I watch a machine shut down because of a circuitry issue I think of the idea of autonomous cars and scratch my head.

HVACNUT

It could be high vacuum on the suction line. The longer it runs, the higher the vacuum. 
How old is the EK to have high and low limits and a Danfos fuel pump?

Mikeman

Installed September 1990. It's been a pretty good boiler. Over the years I have replaced the hot water storage tank, the firebox, the original classic control with another classic, two circulator motor cartridges, the original removable cabinet panel w/insulation board and one primary burner. The burner ran fine since I last posted but last night I heard a few short cycles so I went to the basement and watched the unit run. I have two zones with cast iron radiators and two with finned tube baseboard. Turning on from a relatively cold start, the burner runs non-stop for quite awhile on the radiator zones. While I was observing I noticed that the short cycles appeared to be momentary flame out and restart when the burner should be running non-stop. This happened two or three times in less than 30 seconds and then ran fine for the rest of the time I watched. I figured fuel or ignition would be the first things to consider. I figured if it was fuel related it would be a more consistent issue. That made me think that perhaps the burner primary control may be having intermittent hiccups on the cad cell operation. The control was ten years old so dropping $50 to replace it was not a bad move in my opinion. I replaced it, so time will tell. One thing I was not sure about was the new Carlin smart control has an optional separate wire for the igniter. Not knowing if that is really a good innovation, I just wired it with the igniter and motor tied together for now. As for fuel, when the technician did the annual service, he told me to think about replacing the pump but said it was running fine at that time. Because it is very old, the next time he's out, I plan to have him replace the pump with a modern model. If this issue pops up again, he'll be getting a call.

Mikeman

"It could be high vacuum on the suction line." HVACNUT...Not exactly sure what you mean by the suction line. The Garber oil filter housing has a gauge on it and it's not detecting any issues. The boiler has been functioning fine since I replaced the burner control but I'm holding back on my victory celebration, as the unit has operated fine for a week and acted up again during this intermittent issue. I have to say it amazes me how one can post a symptom on this forum and get responses of multiple things that could cause it from folks who are far more familiar with the systems and controls.

EdTheHeaterMan

I often though of setting up my VCR video camera on a tripod in front of a boiler and somehow adding a remote start that will turn on the recording every cycle of the heater to detect those hard to find nuisance failures. If I could have invented that remote control VCR starter, I would have made a fortune selling that rig to service technicians. That along with my Shoelace Retipper. Don't you just hate when the lace aglets wear away. I could have been another Ron Popeil! "And that's not all. You also get three 24 hour video tape for that same low three easy payments."

Now all you need is a GoPro and a wifi connection.

Can I interest you in a Pay Phone franchise?

mattmia2

I just used the video recorder on a tablet... And i use tape on the end of the shoelace.

EdTheHeaterMan

mattmia2 said:

I just used the video recorder on a tablet... And i use tape on the end of the shoelace.

Does your shoelace need any aglets replaced?

hot_rod

EdTheHeaterMan said:

I just used the video recorder on a tablet... And i use tape on the end of the shoelace.

Does your shoelace need any aglets replaced?

Heat shrink tubing 

STEVEusaPA

EdTheHeaterMan said:

I often though of setting up my VCR video camera on a tripod in front of a boiler and somehow adding a remote start that will turn on the recording every cycle of the heater to detect those hard to find nuisance failures. If I could have invented that remote control VCR starter, I would have made a fortune selling that rig to service technicians. That along with my Shoelace Retipper. Don't you just hate when the lace aglets wear away. I could have been another Ron Popeil! "And that's not all. You also get three 24 hour video tape for that same low three easy payments."

Now all you need is a GoPro and a wifi connection.

Can I interest you in a Pay Phone franchise?

They used to make a data logging system called OnWatch, where you can hook up to all components, including pressure, vacuum, voltages, aquastat, power venters, flue temperatures and cad cell readings-and log heating calls to help with diagnostics. Unfortunately the owner passed away in 2009 and whoever took over never updated or really continued with it.
It was pricey when I bought it. Haven’t used it in years, and actually only used it less than a dozen times.
Now modern primaries do most of those things.

mattmia2

that is basically what labview and a few other systems for laboratory data collection and control do.

Mikeman

Put a little epoxy on the end of a shoestring and work it in. Lay it on a flat surface and roll a flat object over the epoxied end to compress the diameter. When the epoxy hardens you are good as new.

HVACNUT

Mikeman said:

"It could be high vacuum on the suction line." HVACNUT...Not exactly sure what you mean by the suction line. The Garber oil filter housing has a gauge on it and it's not detecting any issues. 

Sorry about the wording. The feed line. You have a working vacuum gauge at the filter and it stays below 5" throughout an extended run?
You mentioned the burner short cycling off and on 4 or 5 times in 10-20 seconds. That would start me at fuel delivery. Oil line(s) and pump.
You also mention a Carlin smart control, and you wired ignition and motor together. What model primary?You can wire for interrupted ignition. No need to keep the spark going after flame is proven. Especially if it's a 14k volt igniter. They say constant duty but...
Is there a delayed oil valve?
Where is the oil tank?
1 pipe or 2?
How long is the run?
Suction (feed) line off the top or bottom of the tank?
The puff switch is a secondary safety on the EK to prove draft.
Danfos is not my favorite fuel pump but if its working properly and set to the correct pressure, then leave it. And they certainly still make strainers for them. BFPH?

Mikeman

My first thought was fuel also but then why would it run fine for long periods of time after the few short cycles? The problem was not at fire up but with the burner already running. That lead me to believe either the cad cell failed intermittently or the primary burner control was reacting as if the cell was no longer seeing light, shutting the burner off and immediately seeing light again. Either way, when I put on the new Carlin 48245S control, it has been working fine ever since. Time will tell if that continues to prove true. The new control has the extra connection and wire to wire the igniter separately. I just didn't know if there were pros and cons to wiring it that way. It is easy enough to change it. I was hoping to get some feedback from this forum. Oil pump is CFPH and I believe may be the original, making it very old. It has no solenoid valve on it but has a Honeywell unit attached on the burner that the oil line runs through. Perhaps that is what you are referring to. The oil tank is under my front porch in an unheated area. It has one feed line running from a few inches above the bottom to the screw-on oil filter located at the boiler. I assume the puff switch has a diaphragm that uses draft to hold the switch closed and when it senses no draft, allows the switch to open. When you say one pipe or two on the tank do you mean a fill pipe and a vent pipe? It has both. I didn't know anybody did otherwise. Is the device in the attached photo the delayed oil valve you spoke of?

rick in Alaska

When it was short cycling, did the burner (the motor) actually try to shut off, or did it flame out with the motor still running, and then fire back up again with the motor still running. If it actually tried shutting off as if you pulled the power, then I would be looking at the primary control or the power to the primary. The Honeywell 8184 primary would do something like that after it got old because of the relay contacts going bad. I have had some of those controls where you powered it up and it did nothing until you smacked the box, and it would jar the contacts enough to make it come on.
If the motor kept running when it flamed out, the it could be the fuel solenoid, or some other fuel related issue or even a slipping fuel pump coupler.
Rick

Mikeman

"When it was short cycling, did the burner (the motor) actually try to shut off, or did it flame out with the motor still running?" It was very fast, but sounded like it does when it normally shuts down but immediately fired up again. Like I said, I have not detected the issue reoccurring since I replaced the primary control. If it happens again I'll return to the post.

EdTheHeaterMan

This sounds like a bad primary control, and the new Carlin solved the problem @Mikeman .

As far as the one pipe or two pipe system... that is referring to the copper tubing from the tank to the fuel pump. Before copper they used steel pipe and iron fittings. One pipe means there is only 1 copper tube from the tank to the fuel pump. the amount of fuel that moves thru that tube (pipe) is equal to the firing rate of the burner (or nozzle size)

Two pipe has two copper tubes (pipes) from the tank to the fuel pump. The oil in that pipe moves at a much greater rate, the rate of the pump's gear set. In the case of that Danfoss pump it is over 12 GPH. Any oil that is not sent to the nozzle to burn, is sent back to the tank in the second tube (return pipe). This is considered self priming, that means you don't have to open the bleed port at the pump to prime the burner.

Sometimes we use trade jargon and assume everyone knows what we are talking about. I hope this makes one and two pipe fuel system much more clearer.

We will be here if you have a future issue