Boiler going into "lockout" mode

[watson524]

Hi all,

On Saturday, our boiler started randomly putting itself into lock out mode. This was only noticed because my husband said he had a cold shower. We have a Weil McLain oil fired boiler, oil hot water baseboard heat and a Boilermate tank for hot water. As a result of this thread (http://www.terrylove.com/forums/show...ate-Coil-issue) I disconnected the blue wire on the hi/low control so that we had cold start and also have the valves to/from the boiler coil shut off. Not at all saying that is causing our current issue but I wanted to be clear on what's what and also note that since that was done, we haven't had a lick of problems until now.

The boiler was installed new with house construction in May 2002. We now have a 8184G primary controller because in November 2006, our original primary controller (a 60200 Weil McLain - the one with the big red rubber button) went faulty so the oil company replaced it with the 8184G.

We also have a power vent vs a chimney. I've read about the general disdain for those but since our builder didn't even give us an option when we were building and I didn't learn of the issues until after, it is what it is and has been ok so far.

When my husband reported cold shower, we went to the basement and the primary controller was locked out but on the panel, the boilermate was calling for it. We hit the red reset button and it heated up to the 180'ish we'd expect it to and all was normal. Later that day, we checked again and it was locked out (I think this was after running a load of laundry). Hit the reset button and nothing. Flipped the little black switch on it, that did the trick. Ran the normal on/off cycle. Similar behavior yesterday too. We thought perhaps the barometric dampener flap on the flue was sticking because it wasn't rotating quite freely but a gentle nudge unstuck it. Also, for a test, I forceably held flap shut with my finger while the boiler was running but it ran the normal cycle. We did clean just inside the flap area with a wire brush while running a vaccuum hose there just in case, but it flips freely now. Also, I opened up the little inspection plate to check for flame. I'm not sure what it's supposed to look like but it's a big bright orange flame :-) This morning my husband went down to check and it was locked out again though nothing would have called for it since the last reset since showers and laundry were done last nite, though I guess boilermate could have needed warm up.

This year when the oil company cleaned the boiler in the fall, I didn't get their slip to show what was done. We've had some issues in the past with various size nozzles (one time the "eye" in there was sooted up and they cleaned it off) but for the last at least 4 years at cleaning, the nozzle is the 85-80b and has been working well.

Is there anything I can check before I call the service company for what might be something stupid and easy?

I thought about opening it up and seeing if I could determine if the eye was just dirty but it seems odd that when we're standing there, it comes back on and runs fine and when we walk away, it doesn't. I know that that whole front panel swings open after you unbolt the one bolt on the left there but I didn't know if the oil line swung with it (copper line, can't imagine it'd bend easy) or if that should be disconnected somehow.

Any help would be great. If anyone needs pictures or anything, just let me know.

thanks!

P.S. yes I know about the master power off switch and we shut the system down while cleaning dampener area

P.P.S. oil tanks are plenty full.

[jadnashua]

Check the boiler water pressure. Generally, it needs to be something like 14-20#. If it is low, the boiler will shut down. You should have the owner's manual (if you don't, check online for it). It will have some troubleshooting info.

There are various interlocks, and if you can figure out the wiring diagram, it is generally fairly easy to see what switch or control is not functioning. To do this, you'd need a meter and know how to use it (well, you could use a 24v lamp and some leads, but that is a little harder). Various interlocks might be things like: flame sensor, flue damper, pressure (vacuum) indicating there is a fan on, low water pressure, high temp and maybe others. If the circulator isn't running, the boiler can get too hot since the water isn't moving. Lots of things, but if you are logical, easy enough.

[watson524]

The pressure was reading ok (we were watching that and temp) but of course when we're standing there, it runs fine, but I presume if it did go low, it wouldn't just randomly come back up even when not running when we went to check on it.

When you say interlocks, do you mean on that primary controller? The circulator is definitely running (I checked that on a hot water call and a heat call and both were ok).

[Tom Sawyer]

Nope the boiler will not shut down if the pressure is low. If it has a low water cutoff it will shut down if the water level drops drastically as in a big leak. It could be any one of a whole lot of things from bad or dirty cad cell eye to bad nozzle, electrodes, transformer, pump, pump coupling, burner motor, draft issue, plugged filter or pump strainer, fluctuating power, bad primary control, get the picture? Without test equipment and experience you are shooting in the dark.

[watson524]

So translated as - call a tech. I guess I'm just leery given they installed a boiler mate and left me getting hot water from the coil. The manual troubleshooting page lists a bunch of scenarios, none of which are lockout related. Maybe I'll try opening it up and at least cleaning the eye. I am not going so far as to messing with how electrodes are pointed and such.

[jadnashua]

My (gas) boiler will shut down if the primary loop pressure is too low...I'm guessing, since this one and the last both had it, that that is a fairly common interlock function, but I have no experience with an oil fired boiler.

Some things are fundamentally the same, though. THere's normally some sensor to determine that the flame actually got lit - you don't want to continue to add fuel if it isn't lit. On a power vent, there are interlocks that determine the fan is running and the vent is not blocked (either by pressure or vacuum - those I've seen use vacuum, though). Other than that, you'd need to review the manual to determine what's in yours, and what may cause it to shut down. Some functions are 'catastrphic' and won't reset by themselves; others are condition based, and if a transient condition, will reset and then things can work normally.

[watson524]

Well I took some manuals that we got with the boiler down there and looked at some things. Apparently our failures are of the "we aren't restarting without you at least hitting the switch" kind. Now today we haven't had a call for hot water so all was fine all day. That being said, we've verified that the power venter fan is running, the dampener is moving freely and there's nothing stuck in there (we looked from outside too in case a bird or some stupid thing got in there). I flipped the switch on the primary control to force lock out, that did what it was supposed to. I opened up primary control box, all wiring connections are solid and not corroded. So then I opened the thing up and looked at the eye, clean as a whistle. THEN we got brave and took out the electrode and nozzle setup. The nozzle is an .85 80b which is what we've been getting in there since at least 2006 (we changed oil companies and I only have slips from the new company), even though the book mentions 1.25 but I remember way back when, they dropped the nozzle because it was using so much oil and since we've been ok for 5 years, I can't see how nozzle size would be an issue. The top of the nozzle right under the electrodes was pretty gunked up so I wiped that off (hole part was clean though so I don't where I was wiping mattered). The tips of the electrodes were basically to the specs as far as how far apart, how far in front of nozzle and how far above spray but for good measure we covered the nozzle and wire brushed the ends lightly. Then put it all back together. Turned up thermostat and it called for heat and the thing ran fine.... Ok, crossed our fingers, about an hour went by, started making dinner and I guess used enough hot water to call for it from the boilermate and my husband went down and it's in lockout. *&%$#@!!! So he hit the reset, it started up and then about 30 seconds later, the zone stopped calling so it shut off. Now when he goes in the shower tonite, I'm going to go sit there and watch the sequence of events. This is just annoying that it won't do it WHILE we're sitting there so I don't know what the heck to tell a tech....

[jadnashua]

Sort of like the saying, a watched pot never boils...I can appreciate that, not nice! Good luck.

[watson524]

Well finally I saw the thing go off. Nothing calling for anything, all was calm. Turned on hot water for shower, zone called for it, power vent came on just fine, no fire, 45 seconds later, red light of death and lockout. Hot water still calling for it. About 30 seconds later, I hit reset button, ran whole cycle with no issues and shut off (power venter off 3 minutes later). Ok so what does that tell me? Well, I know that every time I've been able to hit reset and have it run just fine and now I know that I can hit reset RIGHT after it locks out (vs some time later when I find said problem). So then I thought, ok I know the reset works if something is calling for it when I reset it. Now what I am going to test next (this may mean nothing to the pros, but in my mind it makes sense), is if the reset will work when nothing is calling for it. Unfortunately, we turned up a heat zone and the dumb thing fired so maybe it needs to cool off. Tomorrow morning I am going to turn up a heat zone and let it call, hopefully have it lock out but instead of resetting while calling, I'm going to turn thermo back, turn off call for heat, THEN hit reset and then turn heat back up for call and see what's what.

Beyond all this, it looks very easy to replace the controller myself. Since we had one go 4 years in, maybe this one went after 5 years. Is that reasonable to do for $70 in a part before I go calling in the service guys? Not trying to short change the value of a qualified tech, but since it's not winter and we're not using heat here and for showers and washing it successfully resets each time, I'm allowing myself to take some time for some troubleshooting and learning before I call UNCLE.

[DonL]

If it uses a CAD cell flame sensor then you may want to check its resistance.

And make sure that the fuel pressure feeding the nozzle is correct.


DonL

[watson524]

I'm pretty sure I don't have a way to check the fuel pressure into the nozzle but I have a multimeter and can read ohms if someone can point me to where to read it from and under what conditions (i.e. running or not running but with power to the system). You mean that "eye" thing in the flip up part that I checked for clean before, right? Right near the coils that rest on the electrode ends when the flip up part is closed.

[watson524]

Actually, maybe I am over complicating things. Where the sensor is wired in (yellow wire) to the two terminals on the primary control is probably what I should be testing. I would imagine 0 or very close to it when the boiler isn't firing and some higher value (not sure what) across those two screws when the boiler is firing?

[DonL]

I am not sure on your unit, but if you changed the nozzle size then you should have adjusted the pressure for the new nozzle.
If the Cad Cell does not see the flame then it shuts off.

I think that it is a safety thing and replacing the controller may not fix the problem, you need to check what info that the controller is getting. I do know that flame out will turn it off.

If you changed the nozzle and did not adjust the nozzle pressure, then in may have not been burning correct.

I would check to see if the CAD cell is seeing the flame, and that its resistance is correct.

If you can not measure the nozzle pressure, and adjust it to the proper pressure then you may need a pro to help you.

Jim knows more about them systems than I do. I think that He is the man for your best help.


DonL


Just a guide line;
"For a properly adjusted burner, during operation, the cad cell resistance should be approximately 300-1000 ohms, but not more than 1600 ohms. A resistance above 1600 ohms signals a problem that should be corrected."

[watson524]

I didn't personally change any nozzles. I do happen to have a spare 1.00 something (can't remember if it's an 80a or 80b or something else) but I didn't want to put that in. This same size nozzle has been in use and replaced once / year at fall cleaning time since at least 2006 and has been working ok so...

This morning it was locked out again, hit reset, started right up since water tank was still calling for it. While running, resistance across the F terminals on the primary controller was 343 - 380 ohms which is in spec from what I understand. When it ran the full cycle and shut off, the resistance went to nothing (which is 1 on my meter). So all that seems fine.

I was hoping to test my theory of if it'll start right back up when there's no call but when I turned up the wall thermostat hoping to lock it out so I could turn it back and reset it, it started right up just fine. It's like if it's warmed up, it'll run and start with no issues. So I'm letting it cool back down before I try that test again. I've also turned the water tank down to about 110 so that's not calling as often while I test. And I had a fleeting thought that after a month it didn't like the cold start and maybe I'd plug the blue wire on the hi/low control back in but since it restarts each time just fine and that's cold then too, that makes no sense so I won't bother with that test.

[BobL43]

Oil burner service is not rocket science, but you definitely need to know what you are doing. Over the years I have serviced mine several times and did fine with cleaning the boiler, replacing the nozzle,oil filter, cleaning and setting the electrodes, etc. I did as well as the techs that my various oil companies techs did that they sent out in the 40 years I've been in my house. I even replaced the original burner myself with a Becket AFG to replace the piece of crap that was there. Actually, I had an oil company replace the entire piece of junk steel boiler and its burner in 1986. They had put in a Weil MCclane and a Blue Angel burner, but nobody seemed to know how to set up the Blue angel, and the service techs, when they came, always said it was diificult if impossible to adjust it; so, I was too cheap to pay them what they wanted, so I bought the Beckett at the supply house.The only thing for me is getting the combustion air set correctly (well, I did it by eye and did not have even a smoke test device). All the years that the techs the companies serviced my burners, not ONE of them ever had a combustion analyzer; they set the flame by eye, and some did a smoke test with the little hand operated suction pump that pulled some flue gases through a paper filter. Several years ago, when I did not feel like doing it anymore, I asked a friend of mine to service it for me, and he used a B******ch (spelling?) analyzer to set it. He was very maticulous in everything he did. Most of the techs that the oil companies sent out were of the Hunch back of Notre Dame's mentality. There were a few that knew what they were doing, some cared, but NONE had the combustion analyzer. I think it is likely that if I hired an HVAC company to send a tech out, they would be equipped with the analyzer (maybe).

Most importantly, if you really get it wrong and burning dirty, it will not only soot up and dirty up the cad-cell eye, it will be dangerous.

I am an advanced DIY guy and have been in the industrial automation controls industry for a long time and did it myself at times because of the level of skill of the techs they sent out to my house.
Again, its not rocket science, but I recommend you get somebody in that is a pro. Troubleshooting the cause of it locking out, as Jim says could be easy enough, but if it involves getting the combustion set up properly, I say: get a pro there. If you saw it call for heat, and the burner motor never even make an attempt to start, then maybe the primary control is faulty. You sound like you can do that with everything else you have checked.
Did the motor turn over when you saw the thing go off on "flame-out"?
my 2 cents here (maybe not even worth that much!) ;-)