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Boiler upgrade?

haybales
haybales Member Posts: 10
A year ago I purchased a home with a Burnham P204A-WNI gas cast-iron boiler which heats cast-iron baseboard radiators. The boiler was installed in 1992 and has been well-maintained, but is in need of a gas control valve repair. I also have an electric water heater that just went out.

I'm faced with either repairing the Burnham and upgrading to a gas water heater, or replacing the entire system with a high efficiency mod-con unit combined with DHW.

I'm not looking to spend money I don't need to, but am also trying to look ahead. Local plumbers guesses for longevity of a Burnham cast-iron boiler vary widely...anywhere from 20 years to 60 years.

After accounting for tax credits and energy rebates, the complete upgrade to a Triangle Tube Prestige Excellence would run about 3k additional as opposed to just fixing the existing 18-year-old boiler and installing a new gas-condensing hot water heater. My gas bills are quite low, and so gains in efficiency will not result in a dramatic and offsetting savings. But I also don't want to wind up spending 6k five or so years from now to replace a boiler, when I could've taken advantage of some good incentives now.

Any thoughts?

Comments

  • Tim McElwain
    Tim McElwain Member Posts: 4,612
    What is wrong with the gas valve

    why does it need repairs versus replacement?
  • haybales
    haybales Member Posts: 10
    Gas Control Valve rattles

    Thanks for the reply!



    As soon as the boiler fires up, the gas control valve rattles loudly and vibrates. The boiler seems to fire fine, but the noise and vibration continues. So I assume that it is either the gas control valve itself, or the electronic signal which controls its operation. I've been provided an estimate of a few hundred dollars to repair.
  • Tim McElwain
    Tim McElwain Member Posts: 4,612
    What are the make and numbers

    on the valve and controls, that is a very unusual problem which may be combustion related and not the gas valve.
  • haybales
    haybales Member Posts: 10
    Honeywell VR8204C 3007 gas valve

    We first experienced the problem last fall, the first day we moved into the house. The boiler had yet to be used that season, and when I turned it on the first morning in the house, it acted as it is now. After turning off and back on several times with no luck, I did call the original installer who came out that day. He wiggled all the wire connections before having me turn the thermostat up, and of course it fired properly with no acting up at all. I didn't know it until now, but my wife said it did act up a few other times during the heating season, but she was able to correct it simply by turning the boiler off and back on.



    I first attempted to fire up the boiler this season about 1 month ago, and it has performed consistently on every attempt since (I too have made sure all electrical connections are secure, including wiggling each on while the boiler is running). I did an annual cleaning this past weekend (including cleaning the ignition electrode/sensing probe with emery paper), hoping that might improve things, but no such luck. The burners are absolutely pristine (the previous owner was a maintenence man for the local school district, and so knew how to care for a boiler).



    When fired, the flame looks good to me (admittedly I have no experience and only common sense and the boiler's manual to go off of).



    If it is a combustion issue, what is the likely cause and remedy?



    Again, I am faced with a repair to this, plus replacing a water heater, versus extending myself for another 3k or so and upgrading to a TT Prestige (either Excellence or Solo with indirect 30).



    Thanks again for your consideration and input, it is appreciated immensely!
  • haybales
    haybales Member Posts: 10
    Other Honeywell controls

    Other controls are:



    S8610M Continuous Re-try, 100% Shutoff IP, 90 sec trial for ignition



    R8285D 1026 relay and 9235 R822U 1006 transformer
  • Slimpickins
    Slimpickins Member Posts: 339
    gas valve rattling

    Sounds like the supply pressure may be too high and hopefully your plumber checked that. The regulator at your meter may be bad.
  • haybales
    haybales Member Posts: 10
    Supply pressure ok

    Thanks for the tip about possible high supply pressure. High pressure might've also explained a very, very small gas leak on the supply line shut-off valve. I called the gas company and they came out and put a guage on the line, but it checked out well within limits.
  • haybales
    haybales Member Posts: 10
    Troubleshoot controls

    If a control problem, is there a more likely culprit, and how do I best go about troubleshooting the various controls?
  • Tim McElwain
    Tim McElwain Member Posts: 4,612
    That gas valve

    is a step opening gas valve. It should come on with a low fire and then about 10 seconds later go up to full fire. Does it do that when you first turn it on? Have your technician check the outlet of the gas valve to make sure the sensing port up inside the valve  outlet is not partially plugged, often Teflon tape or pipe dope will do this.



    Make sure if you replace the valve to have the gas pressure checked and have a combustion analysis done on the boiler.
  • haybales
    haybales Member Posts: 10
    Valve or other controls

    Thanks, Tim! Do you think it's most likely the valve, then, or could other controls be causing this behavior?



    And do you have any opinion and whether to fix this along with installing a new hot water heater, or bite the bullet and take the oppurtunity to go with a high-efficiency mod-con?
  • haybales
    haybales Member Posts: 10
    Step opening valve

    Almost forgot... yes, it does come on with a low fire and then step up to a high fire.
  • Tim McElwain
    Tim McElwain Member Posts: 4,612
    I would make sure

    you find out exactly what is wrong before replacing anything. Have a professional gas technician check it out. I would also get an estimate on what it is going to cost to repair. A Mod/Con system is not cheap so you are looking at a large investment. With the Mod/Con you could install a indirect for domestic hot water. If your pocket book can handle it go ahead as you will certainly see an improvement in efficiency. If not fix what you have and install a standard water heater much cheaper in the long run probably.



    It is hard to say if your problem is the gas valve without being there in person to check everything and see exactly what it is doing. You pretty much have to trust the repairman's recommendation if they feel it is the valve then let them change it.
  • Tim McElwain
    Tim McElwain Member Posts: 4,612
    So then it is an

    intermittent problem that is not occuring all the time. I wish I could hear what it is doing as it is hard to diagnos without hearing it or actually being there.



    If it is coming on low and then up to high that is proper operation.
  • Tim McElwain
    Tim McElwain Member Posts: 4,612
    It is hard to say

    try to get someone who understand the system to take a look at it and do a combustion test.



    Some pictures of the installation might help so we can see if there is anything installed incorrectly or vented wrong.
  • haybales
    haybales Member Posts: 10
    No longer intermittent

    The problem was intermittent last year (only happened once for me and a couple of times for my wife) but now is consistent. The boiler fires normally, but is not really usable due to the loud racket and vibration from the gas valve.
  • haybales
    haybales Member Posts: 10
    Bad Gas Control Valve

    I checked the voltage coming from the ignition module this morning and it was good... 24V. A heating repair tech came out and swapped out the gas control valve, and the boiler is humming right along now, hopefully for another 20 years.



    Now to attend to the water heater...



    I'd really love to go with an indirect, but with all the rebates and incentives out there now, will likely settle for a Vertex gas condensing.



    Thanks again!
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