Propane issue causing boiler burner fault?

sunlight35

I have a 7-yr old Viessmann vitodens-200 boiler that's been running fine for the first six years then suddenly experiencing burner fault (code Eb) in multiple occasions since this winter. The installer has replaced gas valve, fan, ionization rod and ignition electrodes. Every time after the service call the boiler would run fine for 2-3 weeks before the same burner fault showed up. The installer also did a thorough check to make sure nothing was wrong with the boiler itself, he checked the gas pressure, flue system, etc. With very few options left I want to ask the propane company to set up a temporary tank next to the house and run the boiler off that to rule out it's (or not) the propane issue, I was on the phone with a propane manager and he suggested to replace the propane pressure regulator, if that fails to resolve the issue then we will set up the temporary tank.
Anything else helpful you guys can think of? Thanks!

EdTheHeaterMan

Before the problems, were there any maintenance or service calls completed? If Yes , could the parameters for LP gas be changed? Could air-fuel mixture be changed? Could air intake or flue gas exhaust blockage be a problem?

Lack of maintenance is usually not addressed in the troubleshooting section in the manual. When they write those manuals they are working with new equipment. 6 years is a long time to not clean the "innards" of a heater. Expecially them new fangled things

Ironman

When was the heat exchanger last cleaned? The condensate trap and drain line?

sunlight35

EdTheHeaterMan said:

Before the problems, were there any maintenance or service calls completed? If Yes , could the parameters for LP gas be changed? Could air-fuel mixture be changed? Could air intake or flue gas exhaust blockage be a problem?

Lack of maintenance is usually not addressed in the troubleshooting section in the manual. When they write those manuals they are working with new equipment. 6 years is a long time to not clean the "innards" of a heater. Expecially them new fangled things

Yes, the boiler had always been serviced annually by the same contractor since the first year.
Both Air intake and exhaust pipes have been examined and they are free of blockage.

sunlight35

Ironman said:

When was the heat exchanger last cleaned? The condensate trap and drain line?

Last maintenance was done in last November

Ironman

But did he clean the heat exchanger as prescribed in the manual?
IDK about your situation, but most "annual maintenance" calls done in this industry are a sham compared to what should be done.

HVACNUT

Do you have the combustion report from the last maintenance? It should be there.

sunlight35

I didn't ask for those reports, but so far what do you suggest could be the source of issue?

Ironman

sunlight35 said:

I didn't ask for those reports, but so far what do you suggest could be the source of issue?

It appears from the way that parts were replaced by guessing, rather than diagnosing, that whether PROPER maintenance was performed is suspect.

Without being onsite and being able to DIAGNOSE, you're asking us to GUESS, and lack of proper maintenance appears to be the consensus.

We want to help, but we can only give advice commensurate with the info that you provide and so far that only includes the parts that were changed and the fact that someone came out annually to service it. That may eliminate some possibilities, but it's not data from which a diagnosis can be made.

Things such as combustion analysis numbers, static and operating gas pressure, burner gas pressure, flame signal strength, the actual extent of maintenance, some pics of the boiler, its venting, etc, would be helpful. Even more helpful would be pics of the interior showing the heat exchanger and burner. Of course, that requires opening up the boiler.

Right now, your description is like someone calling an auto mechanical and saying "my car won't start. I've put gas in it, replaced the battery, alternator, and changed the oil. What do you think is wrong."

You can have the LP company replace the regulator(s), and that may fix the problem or you can get a technician that has the tools and knowledge of how to diagnose. That person can often be hard to find.

sunlight35

Thank you Ironman, I understand your reasoning.
What's the chance of having too much methanol in propane would cause burner issue? I am going to ask the propane company see if they can check the gas quality.

Ironman

That's something you need to ask your LP supplier, but I've never seen it happen around here.

You seem to be fixated on the gas supply being the problem because you state "there are very few other options", but until a proper evaluation and diagnosis of the boiler is done, I cannot agree with that conclusion though it is a possibility.

Deductive reasoning is part of the diagnostic process, but it must be based upon facts (actual readings, measurements, observations), not assumptions.

sunlight35

I recorded a video of the start-up:
https://www.youtube.com/watch?v=LTqt_xNjvi0

See if it offers any clue from the sound that it made.

Ironman

That doesn't really offer much other than it showed 73* outside temp. If that's correct, th boiler would be in WWSD.

sunlight35

There is a call from DHW

dopey27177

Did this problem occur in days when the temperatures were near 0 degrees. some times when you have a long run of pipe from the propane tank the propane stays in a liquid state and does not become a gas.

I had a friend that ran into this problem, the cure was to put a ten gallon tank in the house to collect the liquid and allow it evaporate and become gaseous. The outlet tap was from the top of the tank the inlet also was at the top of the tank with a syphon tube to have the liquid deposited to the bottom of tank.

Never had the problem again.

Jake

Zman

Find out if a combustion analysis has been performed. Some companies have a different idea when it comes to proper annual maintenance.

sunlight35

dopey27177 said:

Did this problem occur in days when the temperatures were near 0 degrees.

We had a mild winter this year so this problem happened when temperatures were mostly above 32F

Solid_Fuel_Man

That burner light-off sounds very lean.

You need combustion numbers, on a clean heat exchanger to go any further!

Excessive methanol in LP cab make the burner wistle and has a bit of a funny smell from the combustion.