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Update on Crown Boiler Problems

led
led Member Posts: 7
I want others with a similar Crown boiler to be aware of my problems with this boiler so they can have their heating professional perform inspections and any necessary repairs to ensure its continued safe and reliable operation.

As background My BWC225 was installed in Feb 2011 -- the boiler stopped working in July 2013 due to a mechanical failure of the venturi on the gas valve that combines air and fuel that is the inducted into the combustion chamber. The inlet to the venturi had eroded sufficiently to result in a non-combustible air-fuel ratio. At the same time the Honeywell controller failed while the heating professional was trying to determine the reason for the boiler malfunction. It took over a month to identify the failure and get the boiler back into operation. I posted this failure on this site at the time to see if others had similar problems but none were identified. I received comments that the failure of the venturi may be due to fuel gas contamination of the inlet air.

Since my original discussion of the problem with the Crown BWC225 boiler over three years ago the following has occurred:

- The installer re-oriented the air intake and flue piping in response to comments received on my first posting -- they are in compliance with the Crown installation requirements. I purchased a digital combustion analyzer and performed tests before and after the change in orientation and did not detect any differences.

- I replaced the gas valve venturi in 2013 -- I inspect the new venturi regularly -- it is eroding in the same place the original failed. This boiler has a piece of bent tubing that directs the air into the inlet of the venturi. I understand from discussions with suppliers of similar Burnham designs there is no tubing on the inlet. The bend in the tubing will distort the flow profile entering the venturi which may be a potential cause of the erosion. I have not been able to find a source for the venturi alone without purchasing a complete gas valve with a cost in excess of $500. My heating professional is helping look for one. I already have a new gas valve that I had to buy when the first venture failed. I don't need a third one. I suggest that if you have a similar boiler that you have your heating professional inspect it.

- I run combustion tests periodically and have had to adjust the fuel air ratio to maintain the CO, CO2 and O2 in the "factory-test" values. As the venturi erodes and the fuel air ratio changes I am concerned with the increase in CO and potential release into the air during ignition (see below discussion of problems with the spark igniter). The boiler is in an attached garage -- I have two CO detectors just inside the door that leads from the garage into the house. They have not alarmed to-date.

- The original Honeywell controller on the boiler failed about the same time as the venturi in 2013. We replaced it but that one also failed so I am now on my third controller -- they cost in the range of $800 -- Crown had no explanation for the failures. I contacted Honeywell about the failures but they took no responsibility since the manufacturer -- Crown in this case -- does the programming and installation

- I am on my fourth spark igniter -- they sit in the flame and distort sufficiently to eventually cause a delay in ignition with a very energetic ignition -- a very large boom that can be felt inside the house. I do replace them when this occurs. The last igniter only lasted 9 months -- they cost in the range of $100.

- I have had several other "minor" failures of temperature sensors and the aquastat on the mega-stor domestic hot water tank.

My experience with Crown has not been satisfactory when trying to understand the mechanisms for these failures -- I hope others have better experience. If you are in the market for a new boiler I would not recommend Crown. I have over $16,000 invested in this unit that is less than 6 years old, but am considering replacing it and possibly my whole house heating and hot water system to do away with a boiler. That will not be cheap.

Comments

  • NY_Rob
    NY_Rob Member Posts: 1,370
    Wow... that's dissapointing to say the least!

    Seems like most if not all of the repairs should have been covered under warranty... was that not the case?
  • Fred
    Fred Member Posts: 8,542
    Strange, Crown has a pretty good reputation. Have you asked them to send a factory Rep out to inspect/advise you on what might be going on? I would think if they could see the service history on this unit, they'd be interested in figuring it out. Are there any environmental elements that might be contributing to these problems? Excessive moisture/humidity? Chemical storage near/around the boiler? If it was/is a common problem with the Crown boilers, the Pros on this site aren't bashful about sharing their experiences.
  • kcopp
    kcopp Member Posts: 4,419
    Makes me wonder about the venting. It there cross contamination?
    That would erode the venturi away.
    SWEIAlan (California Radiant) ForbesGGross
  • njtommy
    njtommy Member Posts: 1,105
    Makes you wonder why you need 225,000 btus of heat. How big is the house?
  • led
    led Member Posts: 7
    Thanks for the comments -- in summary:

    The first failures occurred a couple of months after the warranty expired.

    Crown was not interested in investigating the venturi failure even though I sent pictures and requested they provide an explanation. After no mechanism was ID'd I requested that they send a technician so it wouldn't recur. Since the replaced venturi is now also eroding there is clearly either a generic issue (although I have not heard of any others with this problem), or I have a lemon, or there is an installation problem that is not obvious. I am not sure they sold very many of this unit -- it is large and at the time a new high efficiency design. I don't know if it is still on the market -- I know they are pushing a different series.

    The house is ~5000 sqft with four heating zones.

    We checked for cross-contamination and did not identify any mechanism unless it is some internal path that is not visible when the unit is buttoned-up.

    I have a new heating professional that is a long time Burnham installer -- hopefully he can figure it out.
  • njtommy
    njtommy Member Posts: 1,105
    edited January 2017
    How far part is the intake and exhaust?
    kcopp
  • Ironman
    Ironman Member Posts: 7,367
    Can you post some pics of the vent termination, the boiler and it's near piping?
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • ChucksOldBoiler
    ChucksOldBoiler Member Posts: 14
    I feel your pain!
    I also have a Crown BWC225 installed in October 2009
    After 13 years of absolutely NO SERVICE,, it finally broke.
    I replaced the Ignition Electrode & Cable but still doesn't work.
    4 service technicians can't get the burner to fire on Pre-start.
    One of them cleaned the SEVERELY CLOGGED heat exchanger.
    Crown is absolutely NO HELP!
    Initially, I thought the gas vale was defective or out of adjustment. 24vdc is present.
    After I increased the MIN setting, it fired up.
    The flame is mostly YELLOW and I don't know what to do next.
    PS. I fix Trolleys and Pinball machines for the past 50 years and know NOTHING about Gas Boilers.
  • Jamie Hall
    Jamie Hall Member Posts: 23,170
    Flame mostly yellow? The burner is seriously out of adjustment. I hate to think what the carbon monoxide levels are...

    I've said it before, a little more gently, but -- you are playing a very dangerous, and possibly lethal game. Stop.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    EdTheHeaterMan
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,725
    @ChucksOldBoiler
    Have you read and followed the directions on Page 49 & 50 of the IO Manual? The section called MAINTENANCE. If you did and you followed the annual maintenance, your professional boiler service tech would have looked at that ignition electrode and cable 12 times in the pas 13 years. Also the heat exchanger would have never been "CLOGGED" with 13 yers of debris from the normal combustion process.

    If I was on the other end of that phone call to Crown Boiler Tech Support, I would be laughing my **** off at the stupidity of anyone that thinks that operating anything with a hydrocarbon passing thru it without any maintenance for 13 years and thinking there should be no problem, was a total idiot. Good thing I don't work for Crown, But I didn't like having idiots for customers when I was in business.

    But That is just me.

    Me. ED

    And heed @Jamie Hall's advise

    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
    Alan (California Radiant) ForbesGGross
  • ChucksOldBoiler
    ChucksOldBoiler Member Posts: 14
    Is there a test port to measure the gas on this valve?
    See pics below Honeywell Gas Valve VK8115V 1036 4. adjustments view
    Honeywell Gas Valve VK8115V 1036 4. Label view




    Honeywell What is it? VK8115F 1134 4. Label view


    BWC225 with burner ON ( Is this a good flame? )

  • ChucksOldBoiler
    ChucksOldBoiler Member Posts: 14

    Sorry, the pics don't match the titles
  • pecmsg
    pecmsg Member Posts: 4,776
    I feel your pain! I also have a Crown BWC225 installed in October 2009 After 13 years of absolutely NO SERVICE,, it finally broke. I replaced the Ignition Electrode & Cable but still doesn't work. 4 service technicians can't get the burner to fire on Pre-start. One of them cleaned the SEVERELY CLOGGED heat exchanger. Crown is absolutely NO HELP! Initially, I thought the gas vale was defective or out of adjustment. 24vdc is present. After I increased the MIN setting, it fired up. The flame is mostly YELLOW and I don't know what to do next. PS. I fix Trolleys and Pinball machines for the past 50 years and know NOTHING about Gas Boilers.
    For something that should be serviced annually I wouldn’t complain after 13 years of No Service!
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,725
    edited June 2022
    I believe you have a modulating input boiler. The gas valve opens and has a regulator. On Natural gas you must have at least 3.5"WC pressure at the input side. That is about 0.1246 pounds per sq. inch pressure or 2.023 ounces per sq. inch on a pressure gauge. If you have one that accurate.

    Now once the pressure enters the gas valve the outlet side is then regulated to 0 PSI. Then the combustion fan creates a vacuum based on the RPM of the fan blade. As that vacuum increases the amount of gas from the valve will increase. The fan mixes the air and the fuel and delivers the mixture to the burner. As the heater needs more heat the fan ramps up to the higher input. As the boiler needs less fuel the fan slows down to use less gas and combustion air. It is a pretty ingenious idea in my opinion. Changing the input to match the need of the home based on outside temperature, return water temperature, other sensors and the computer chip in the boiler control.

    I'm thinking that this adjustment should be completed by an experienced trained technician.

    But what do I know?

    This might help in deciding on what to do next.
    From the IO Manual page 43.

    If 4 different technicians can not figure this out, then you are calling the wrong technicians. The ones that know probably will charge more but will get it right the first time.
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • 109A_5
    109A_5 Member Posts: 1,377

    It is a pretty ingenious idea in my opinion.

    Ingenious, yes, too bad they basically stole it from antique automotive engine technology.
    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
    mattmia2
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,725
    109A_5 said:

    It is a pretty ingenious idea in my opinion.

    Ingenious, yes, too bad they basically stole it from antique automotive engine technology.
    Too Bad? I disagree. I think it is a great concept.
    But that is just one old man's opinion
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • 109A_5
    109A_5 Member Posts: 1,377
    edited June 2022
    Google: "The first person to patent a carburetor for use in a petroleum engine was Siegfried Marcus with his 6 July 1872 patent for a device that mixes fuel with air."

    The internal combustion engine is essentially an air pump sucking air through the carburetor (a venturi tube). Combustion Blower same purpose.

    It's 'Too Bad' the heating industry has not come up with anything better. At the point that boiler was built they were using technology that is over 100 years old for the fuel / air metering technology. Carburetors lasted longer than that boiler's gas valve (assuming that is the problem in @ChucksOldBoiler case) and they handled liquid fuel instead of a gaseous fuel, however they did need maintenance, a carburetor rebuild kit was very inexpensive and available, been there, done that.

    Automotive fuel technology has move on, has the heating industry ?

    I like high tech as much as the next guy, made a good living from it. I also really like my old boiler, it is and has been very reliable, and I can power it with a battery during a power failure in the dead of winter.
    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
  • mattmia2
    mattmia2 Member Posts: 9,576
    I mean small engines still use a carburetor. A boiler doesn't have the diversity of operating conditions that an automotive engine has that requires a complex carb to handle. Though the first patent might be 1872 versions that worked well were much later.
  • 109A_5
    109A_5 Member Posts: 1,377
    Yes, thank you, kind of my point, 13 year life for a Gas Valve / Venturi ? That's disgusting.
    How many hundreds of dollars to replace those small engine carburetors ? Which you can probably rebuild for a few dollars. Less diversity, it should last longer with less problems.

    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
  • mattmia2
    mattmia2 Member Posts: 9,576
    I think you can get knocoff carbs for like $20. But if i rebuild a carb and miss something my house probably isn't going to explode.
    Dave Carpentier
  • JefferyLindsey
    JefferyLindsey Member Posts: 2
    109A_5 said:

    Google: "The first person to patent a carburetor for use in a petroleum engine was Siegfried Marcus with his 6 July 1872 patent for a device that mixes fuel with air."

    The internal combustion engine is essentially an air pump sucking air through the carburetor (a venturi tube). Combustion Blower same purpose.

    It's 'Too Bad' the heating industry has not come up with anything better. At the point that boiler was built they were using technology that is over 100 years old for the fuel / air metering technology. Carburetors lasted longer than that boiler's gas valve (assuming that is the problem in @ChucksOldBoiler case) and they handled liquid fuel instead of a gaseous fuel, however they did need maintenance, a carburetor rebuild kit was very inexpensive and available, been there, done that.

    Automotive fuel technology has move on, has the heating industry ?

    I like high tech as much as the next guy, made a good living from it. I also really like my old boiler, it is and has been very reliable, and I can power it with a battery during a power failure in the dead of winter.

    You notice very well .
    fair enough
  • 109A_5
    109A_5 Member Posts: 1,377
    edited June 2022
    @mattmia2, I can certainly play the 'What If' game, maybe that could be another post.

    What is sad here, is folks buy these 'High Tech, Green' appliances (and probably pay more for them) with the hopes of saving on energy costs, only to come to find out in less time than a normal service life they have to spend probably more money than what they saved in energy costs to just keep the thing going. And to make matters worse Service Technicians can't fix it and still hand them a bill.
    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
  • Jamie Hall
    Jamie Hall Member Posts: 23,170
    edited June 2022
    I wouldn't have said stole -- borrowed, perhaps, but the basic technology had been known for a very long time in a variety of applications. The pressure drop in a venturi was known for centuries, and, conveniently, if properly engineered the resulting pressure drop will deliver the right amount of ingredient X -- say fuel -- through a nozzle placed in the venturi. Almost, anyway. Depending on how fancy you want to get, the ratio can be adjusted for varying conditions to a very fine degree -- almost as good as the latest whizzy fuel injection systems with their arrays of sensors and computers working hard.

    Now as anyone who has fiddled much with carburetors can tell you (sometimes with rather colourful language) some carburetors are easier to adjust than others. Triple Solex setups have been known to drive strong men to drink. But it can be done.

    And antique? Got a gas powered generator or lawn mower or chain saw? That's what they use, folks.

    I might add on the gaseous fuel metering. Curiously, t is harder to design an accurate metering system for a gaseous fuel than it is to do one for a liquid fuel. The principle is the same, of course, but the pressure balancing involved is more difficult. There is no particular engineering reason why heating device metering systems can't be operated in a closed loop mode, with appropriate sensors, just as a modern fuel injection system is -- except for the cost/service life equation. We have above someone complaining that their gas valve is having trouble after 13 years of no maintenance. If it were a closed loop system with no maintenance, I doubt that it would have lasted half that at ten times the price.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • 109A_5
    109A_5 Member Posts: 1,377
    @Jamie Hall, OK, I could go with "borrowed", not really a problem for me. I could not find any quick data to the age of the Venturi Tube, I suspected it is a older tech.

    "And antique? Got a gas powered generator or lawn mower or chain saw? That's what they use, folks. " Yes all those, my basic point is they are generally relatively inexpensive to repair or replace the carburetor on. So call it a boiler and the cost goes up to the best part of $1000. Sad.

    Unless a gas is corrosive I would think it would cause less friction wear than a liquid. However this guess a guess on my part. Grand Canyon, Niagara Falls etc. created by air currents ?

    Other than dusting, I have not touched my Honeywell gas valve since the 1990's it still works fine. So put a Venturi on it and the life span significantly diminishes ?

    I'm not saying the heating industry has to directly follow the automotive industry, just do better for their customers. Not a big fan of poor engineering.
    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
  • Jamie Hall
    Jamie Hall Member Posts: 23,170
    no, liquid is more erosive than a gas -- at a given velocity. And those big waterfalls and river channels were cut by moving water -- with a little help from some interesting geology.

    The problem with gas is simply that, being much less dense than a liquid and compressible, the delivery of a gas as compared to a liquid is more sensitive to pressure variations driving the delivery. In most simpler carburtors it is quite sufficient, for instance, to have the float bowl (the pressure in which is local atmospheric) do the job. In higher performance setups, you need to reference the pressure at the carburetor inlet flange instead, to take into account intake filter and other losses. Some late aviation carburetors were pressure carburetors, which didn't have a float bowl at all, but delivered the fuel to the metering system under a calibrated pressure set by the difference between the intake throat air pressure and the venturi throat pressure. Those get expensive...

    I have no idea why the gas train for a gas fired boiler should be expensive, though I suspect both limited production and life safety issues play a part.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Dave Carpentier
    Dave Carpentier Member Posts: 586

    There is no particular engineering reason why heating device metering systems can't be operated in a closed loop mode, with appropriate sensors, just as a modern fuel injection system is -- except for the cost/service life equation. We have above someone complaining that their gas valve is having trouble after 13 years of no maintenance. If it were a closed loop system with no maintenance, I doubt that it would have lasted half that at ten times the price.

    A feedback/closed-loop system would have notified (error code, presumably) that something was out of spec, just like modern automotive engines do. You can keep driving for some period with out of spec f/a mix (according to the O2 sensors, which may be the fault themselves), but eventually in a clogged up boiler situation they would have locked the system down for safety.
    I think, for safety and eco-reasons, we should expect closed-loop combustion heating at some point.
    If combustion heating is allowed to continue, that is..
    30+ yrs in telecom outside plant.
    Currently in building maintenance.