Lochinvar Ignition & Lockout

ayoder56

Hi All -

Long time lurker, first time poster...I have pictures to help newbie questions

Configuration: Lochinvar FTXL boiler (LP) two years old, Ecobee Thermostats

Problem: Starting about a week ago, I started receiving an increase in lockout messages, both "flame fail ignition" and "flame fail running." Also during that same time period, I started to see anomalies on the thermostat: after several hours of the temperature behaving as expected (within 1 degree of the set point), there were long (more than an hour) periods in which the thermostat was calling for heat but the temperature continued to drift down (as low as 5 degrees below the set point) before heating resumed. I started to poke around a bit this weekend, and noticed an increasing discrepancy between ignition attempts and successful ignitions. I suspect that these are related, but there is not a 1:1 correlation so I can't be certain.

I have attached pics of the lockout history, temp, and ignition attempts/successes below to show you what's going on.

Here are my questions:

1) Are the ignition attempts/success related to the lockouts? I assume that there must be more than "x" failures before triggering the lockout condition which would explain what I'm seeing. Correct?

2) What might cause the somewhat random behavior seen here? Most of the time it works fine. And then it doesn't. Then it does. I would think that if it was gas pressure then the errors would be more consistent?

3) The working theory is that the ignition module is beginning to fail. Does that make sense, and would that fail intermittently before failing completely?

4) This problem has been seen over the past week or so during very cold weather. Might that impact?

I have a very simplistic view that when the thermostat calls for heat, the boiler should ignite and heat comes out. I'm struggling with which of the 1,000,001 things might be causing that simplistic view to go wrong.

As an aside....service tech is coming out this week...he's quite good and I'm confident in his approach. I'm picking your collective brains for ideas in the meantime, and will post what he discovers later in the week.

Greg

Ironman

Was a combustion analysis done when the boiler was installed?

I doubt that the board is bad or that there’s a problem with the thermostat.

Zman

Ironman said:

Was a combustion analysis done when the boiler was installed?

I doubt that the board is bad or that there’s a problem with the thermostat.

I agree, It is either a bad ignitor or poor combustion.
How big is your house? That is an enormous boiler for a single family home? What model FTXL?

ayoder56

My bad....it’s not an FTXL....it’s an WHB model. Where is the embarrassed emoji....

A combustion test was done about a year ago. I have no reason to suspect that it’s not “dialed in” properly.

In looking at the bottommost graph, it seems evident that there far more ignition attempts than there are successes. Like, a lot more. So your suggestion of a bad igniter seems reasonable. I guess the only unexplained thing is the ratio of the various failings-There are a lot more ignition failures and temperature drop anomalies than there are lockout conditions.

Ironman

Considering the boiler's only two years old and there's a long history of ignition failures, it's unlikely that the ignitor is bad. Check the ground connections all the way back to the electric panel.

Do you have the numbers from the combustion analysis?

Mike_Sheppard

Clean the flame rod and ignitor.

delta T

2 years is awful short lifespan for a Lochinvar ignitor and flame rod.

WHB is a great boiler, I have installed lots of them. LP can be tricky to tune in properly, and in my experience, depending on your altitude (I'm at 6000 feet) can require a bias adjustment (something that needs to be done while talking to a tech from Lochinvar to keep your warranty) for proper combustion numbers to be achieved. Something that needs to be verified also is that the second stage LP regulator is functioning properly. I have pulled my hair out for hours, before finally checking the regulator to find that it is not functioning correctly. If your did not do this when they did the combustion test, I would ask the static inlet pressure, and the pressure drop when running at full fire. On LP I would want 10" static, and a pressure drop of no more than 2" when at high fire. I would hope for a pressure drop of only .5" or 1". 8" is the minimum inlet pressure for this boiler. When a regulator goes bad you will either see a slow creep of static pressure going up, or you will see a huge drop in dynamic pressure as the gas valve opens. If it drops below 8" you will start to see combustion problems and nuisance lockouts as a result.

This may not be the problem, but just wanted to throw it out there as a possibility.

ayoder56

The plot thickens...my HVAC guy came out today to take a look...he pulled the igniter element and it was very(!!!) dirty. Looked like rust. He said he’d never seen anything like it.

So, assuming that’s the problem - what would cause that to happen?

Some hints...the problem started when it got a bit colder...you can see in the graph that the problem started rather abruptly, seemingly improved for a few days, then steadily bad.

I don’t know how these things work, the chemistry of the components, etc. If replacing the igniter does fix it, I’m still not sure what to do differently so that the problem doesn’t keep occurring.

Thoughts?

Ironman

Some pics of the boiler, its venting and the flue termination would really help. Either your combustion is not properly adjusted or you may be recirculating flue gases.

You stated that a combustion analysis was previously done, do you have the numbers?

ayoder56

Ok, I’ll take some pics today and post. And will ask for the combustion results.

Stay tuned.

vincep99

I have a similar problem, mine is natural gas and less than a year old. Failed to heat about 4 times so far. Last time it happened we pulled the igniter; it was not really dirty but we cleaned it anyway. Worked OK for about a month but failed again last night.
Can you tell me how you pulled that really great history? I assume your boiler status is sent over WiFi to Lochinvar and then you connect to the Lochinvar site to get your history

vincep99

Some more info:
Model KHB110N
Natural gas
Error reads "failed flame ignition"

I hit reset, and is started up OK
Then woke up this morning, same thing

I hit reset, it went through pre-purge, ignition, post-purge; did this cycle 4 times, then went back into lockout
Pressed reset again, same 4 cycles, than back to lockout
3rd time was a charm, finally got it going

I though maybe that the problem was only on start-up but it went into lockout before it reached the set temp

Hope someone can help

vincep99

Correction: the error code is "Flame fail running"

ayoder56

I have a Con-X-Us installed, and it gives me the ability to produce the ignition graphs (and a bunch of other stuff). The thermostat info was pulled down from beestat.io, an Ecobee-related site.

Here are some pics of the igniter. I will provide the vent system pics tomorrow.

blob:null/f3d0a8a7-de8f-481f-acff-2af0b8d78f1c

ayoder56

Hi All - sorry for the delay. Here are the pics of the venting configuration. I’ve read through the manuals, and the only problem that I can see for certain is that the intake/exhaust pipes vent to a “U” shaped portion of the house. This may cause eddy air currents. Not much I can do about that...

blob:null/4904550c-5e25-407b-894e-cb3977be1ced

blob:null/5cc21bea-0b85-42bc-8834-45e2b7c9f2c9

blob:null/1684a3f3-dc3c-41e1-8227-6d68a1d0efb6

blob:null/3e77deaf-f6c1-4231-a629-37e1d330603f


And, finally, I spoke with the guy who replaced the igniter, and he confirmed that he adjusted the combustion. However, he didn’t save a print. Instead he provided the guidelines that he uses as below

blob:null/e93b0022-a6ef-4a4b-aa30-4d243ed6b803

Does this help with the diagnosis?

Ironman

Two things wrong with the vent termination:
1. The exhaust should be at least 12" higher than the intake.
2. It should be at least 4' from an inside corner.

Both of these can cause exhaust gas recirculation.

The old ignitor and flame rod don't look that bad.

Zman

The intake and exhaust are too close to each other, too close to the inside corner and too close to the ground. The boiler is sucking in it's own exhaust which is destroying the boiler.

Then there is the issue with the ridiculous number of 90's and lack of PVC primer and bird screens...

Someone qualified needs to reroute the exhaust and intake per the instructions, disassemble the fan and venturi to inspect for damage and recalibrate the combustion.

Was a permit pulled on this?

ayoder56

Thanks, zman and Ironman.

A couple of things...

Agree that bird screens are necessary - they have now been ordered and will be installed in a week.

Agree there are a lot of 90deg bends...but...as long as the length is less than the equivalent of 100’ (including the penalty that the 90s impose), how much of a problem is that really?

Agree that the exhaust/intake should be at least 12”, and will get that fixed. It’s close, but it’s not 12”. Is there a maximum distance?

The problem that I’m just not sure how to address is the 4’ separation from the sidewall. The design of the house just doesn’t allow for it without the vent pipes being routed such that my wife would shoot me. Is there anything that could be done that would help, if not completely fix, the issue? For example, could I angle the intake at 45deg? Increase the height of the exhaust to increase separation by another 12”?

Thanks again for your help.

Ironman

Sorry, but the laws of physics won't recognize your wife's astetic preferences.

tim smith

Igniter flame rod did not look too bad. Have your contractor look up your boiler ser# on waterheaterrecall.com. Lochinvar tab. It very likely needs the flue sensor grommet replacement. Btw, these are the most reliable condensing boilers we work with. Just an FYI.
Good luck

Zman

If I had no options to vent this so that it was the required 6' from the adjacent wall, I would leave the exhaust where it is and pipe the intake as far away as possible. It would be best if it was on the same wall and at approximately the same elevation. Be sure it is not near other exhausts like clothes dryers.

Your problem is absolutely a result of the boiler pulling in it's own exhaust.

JUGHNE

In the install book there may be an option for using room air for combustion.
You could try that temporally to see if things change.
You would want to cap off the existing inlet pipe so as to not pull the exhaust gases into the room.......also follow the guides for adequate air volume in room and to avoid any contaminants in the room.

Has anyone tried this?

Zman

If you pull it from the space you need to verify all the CA requirements in the mech code. I don't like pulling the building negative. After 2 years running like that something is probably damaged.

ayoder56

Thanks for the ongoing feedback. I'll let you guys explain physics to my wife...

But your points are well taken.

I'm also not a fan of pulling it from inside the house. I'm afraid that will introduce more problems rather than fewer. If I change the air intake to extend it, I'll also reduce the "ridiculous 90s" inside the house. I think I can extend it 3-4' away.

The flue sensor grommet was replaced earlier this year as part of the recall notice.

Ironman

ayoder56 said:

Thanks for the ongoing feedback. I'll let you guys explain physics to my wife...

That's your job my friend. I've got my own to do "nuff splainin to".

vincep99

Thanks everyone for the really good info. Meanwhile the guy who installed mine came over and we worked on it for 3 hours; tried to adjust the mixture but it would not respond. Turns out that the intake had a bird's nest in it!

I am interested to see what kind of bird screen you all recommend. I know it can't be too restrictive as it would reduce airflow

Ironman

Just the plastic or stainless ones that most manufacturers give you with the equipment.

JUGHNE

So the room air intake would have worked, but would have provided more mysteries as to why it worked.

I make my own bird screens out of 1/4" SS mesh.
I cut a circle to just fit inside a hub tightly. Then cut a 3/8" long piece of pipe of that size. Bury the mesh into the hub all the way. Push the short pipe ring up into the hub to keep the mesh from turning sideways. To remove, a screwdriver will pry the ring out and then hook the mesh.
But if you are rebreathing exhaust the 1/4" will frost up under certain conditions.
I was just out last week to clean an intake.
1/2" mesh would keep birds out but still snakes and mice could make it thru.
But less chance of frosting shut.
IIRC, I had a screen included with a Lochinvar, it was a round globe of mesh with a SS plate dividing it in half. It is the size of a softball and mounts on 3" pipe. Never have had that one frost up.

I also put a PVC wye in the horizontal run of inlet pipe, with clean out on the bottom,
the clean out such that it is downstream of the air flow. Drill a drain hole in the plug.
The wye will collect some dirt somewhat like a strainer. The hole would drain any moisture out. If outside inlet is frosted shut tightly and inaccessible, the plug may be removed temporally and then use inside air. Sometimes there is no snow right at the house but may be a 4'+ drift all around that side of the house.
If homeowner calls during a blizzard at 1AM, they can remove the plug and often that gets the heat on after resetting power. They are all advised of this.


I also learned to not assume the function of components;
Had a Loch KBN 106 running, I often check the safeties, on any gas burners, by for instance pull the FS cable off to check if that function is working....well the ignitor doubled as a FS also, had to remove both cables to shut down.

Then I am used to pulling the hoses off the pressure switch for shut down.
Fire stayed on, pressure switch was always NC with fan on or off.
Then learned that this is a blocked inlet NC switch.....if enough negative pressure is developed the board assumes that not enough air is entering and shuts down burner as the pressure switch opens.

Seems to simple to be safe....well if the fan is not running it will suck no gas in, perhaps the board will not open the gas valve at all if a certain RPM is not registered.
FWIW

ayoder56

Hi Everyone - Wanted to provide an update and next steps...

HVAC Tech replaced the ignitor and flame sensor. The results have been spectacular as you can see in the graph below. Not a single ignition miss since the replacement was done.



As expected, when that problem was resolved, the temperatures in the house resumed their very steady performance. The graph below has a red circle on the left, indicating the performance before the component replacement.



I have ordered bird mesh from Amazon. Picture below for vincep99:



My next step will be to rerun the intake air duct. I think I can move it roughly 4' away from the exhaust. I know it's not perfect, but ironman refuses to discuss physics with my wife, so fingers crossed it will work!

Ironman

I don't think that this is a good motto by which to live, but it might help you in this situation with your wife: "it's easier to get forgiveness than permission".

vincep99

Thanks for all the help! Great tips, I will install a mesh. Right now it's 10 degrees outside, so I may wait until we hit a balmy 15

JUGHNE

What is the consensus of extending the inlet horizontally on the exterior of the building for 4'? This would avoid another hole in the rim joist.

ayoder56

Good question r/jughne...looking forward to the responses. I hope so!!!

I've been reading the installation manuals in my spare time, and I believe that even with the 4' extension I will be well under the 100' equivalent length (including the penalties for 90 degree bends). My simplistic thought process being that as long as I'm underneath that total then more separation is a good thing.

I am a bit perplexed, however....the PVC piping certainly appears to be 4" piping while the installation manual clearly calls for 3" intake/exhaust for my system (WHN156). Is it ever permissible to increase the diameter? I'm having my son measure it again to be certain. There's a photo earlier on in this thread if anyone wants to take a look and confirm my suspicions.

ayoder56

Quick update:

Vent caps are on.
Since the igniter/flame sensor were replaced, not a single ignition failure
Temps in the house rock solid

Will extend the air intake this spring and post to the forum the results. But that’ll be awhile.

Thank you all for your advice and counsel.

ayoder56

Hi All -

I wanted to provide an update to this, as there are a few new issues as well as some learnings others may be interested in.

After the igniter/flame sensors were replaced in Feb, the system ran flawlessly. I installed the bird screens at the same time and all was well. Last week, I decided to create separation between the intake/exhaust by extending the intake piping by adding 5' and keeping the exhaust where it was. The job was simple and I believe that by separating the input/exhaust that the problem of the unit "inhaling" the exhaust gasses back in will now be resolved.

However...

Immediately upon extending the pipe, every time the unit kicked on it sounded like a jet engine taking off, with significant vibrations in the unit. Additionally, the unit almost immediately begin experiencing flame fail/ignition problems. This was a head scratcher for me as the extension of the intake was well within the limits define in the installation manual.

I called my HVAC contractor, and the solution was very simple - he drilled a very small hole in the intake pipe which immediately resolved the problem. This is apparently a Lochinvar-approved solution to what is essentially a resonant frequency problem on the intake. Essentially, some combination of length and bends creates the suction vibrations and by drilling a small hole (1 CM or less) the problem was resolved.

I am now eagerly awaiting the heating season to see how the system performs and if the work described above provides a more stable experience.

I'll provide one final update next spring after getting this winter under my belt.

Greg

ayoder56

Final update, just to close out the post. After performing the mods described to separate the intake/exhaust there has not been a single ignition failure this winter. Not one. I ended up painting the intake extension to make my wife happy, so 2-for-2 on this one I think. I am very satisfied with the system.

Thanks to all who offered advice.