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Gas heating system is 25 - 30 years old and working. What would you do?

feetsdr Member Posts: 9
Our slant fin gas fired hot water radiator system is 25 - 30 years old. We haven't done much of anything to it (are you supposed to flush the pipes? How do you check expansion tank, etc.). We did have the gas comapny come out a couple years ago and they blew out dust in the burners / gas line. We get a mostly blue flame (although sometimes it's more yellow. Someone said that might be gas valve on the way to failing problem. Someone else said it's intermittent weak pressure from gas company_

At that age, do you proactively replace the entire unit? Do you proactively replace the thermocouple after x years? Gas valve after Y years? Zone valves after Z years? Do you keep those parts at home ready to go? (is this a DIY forum or for pros?)? If you keep parts, what parts do you keep? Brushes for the circulating pump? 1 zone motor?

Our luck is that problems always seem to happen at the worst times : )


  • Gordy
    Gordy Member Posts: 9,537
    Other than a yearly inspection to check combustion, and cleaning that’s it. If you have no problems I wouldn’t rip it out. Your getting there, but boilers can last over 30 years if maintained properly.
  • delta T
    delta T Member Posts: 883
    edited February 2019
    It would pay to have a knowledgeable service tech come out and service the boiler. There are various things to check and do, and writing it all down here is kind of a waste as there will things particular to your system that may need to be addressed.

    In general, you do not need or really want to drain the system water and flush it out unless you have an issue. The boiler itself should be cleaned and properly serviced and tuned using a combustion analyzer. The gas pressures should be checked both on the inlet and manifold, inlet pressure should be checked static and under load, and a digital combustion analyzer should be used to tune the combustion to the proper range for safety and efficiency. All safety devices should be checked and verified to be operational.

    Where are you located? We may be able to recommend someone who can help you out. If you are looking for a service tech, ask them if they will use a combustion analyzer when they service the boiler. If the say no, or that you don't need one, go to the next company. A 25 year old slant fin......What is the model number? There is a Slant fin model that was made for 2 years in that age range that has a very finicky ignition system on it that should be replaced if it hasn't been already. Is there a fan on the boiler?
    EBEBRATT-Ed Member Posts: 13,427
    The above as mentioned by @Gordy & @delta T is good advise. If it's running ok leave it until the weather warms up
  • feetsdr
    feetsdr Member Posts: 9
    Thanks! DeltaT - we are in central NJ... somerset county. Any recommendations? Is there a certification to look for? Just a plumber that does heating?

    I suppose we should get someone in to look it over / see if it's got life in it or not / what to proactively replace?

    From what I can see, it's a Slant fin sentry S-150-DP

    On the preprinted label, there's text on it that says a-1993. I'm thinking that's the manufacture date? 25+ years old at this point.
    JUGHNE Member Posts: 10,564
    If you post a clear picture of the label showing all info, someone here could tell you the age. That 1993 could be misleading, however it would not be older than that.
    delta T
  • feetsdr
    feetsdr Member Posts: 9
    Here's the label
    JUGHNE Member Posts: 10,564
    I believe that 1993 refers to the most recent document for the ANS.z21.13.
    The DOB is within the serial number most likely.
  • bob eck
    bob eck Member Posts: 930
    Call Slant Fin they can tell you how old the boiler is.