Click here to Find a Contractor in your area.
Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.

Time to Tear Into Things - Need Advice

drewbert41
drewbert41 Member Posts: 58
edited May 17 in Strictly Steam
I have a relatively new Lennox Dunkirk boiler connected to the existing pipes from 1913. The pipes below the water line developed multiple pinhole leaks this season and it is time to rip it all out. It has an extremely low header and I have wet steam and water hammer. There are two mains, but it has only one pipe leading to it and splits later.

If I turn the water off, drain the boiler, and cut out the old pipes do I need to know anything going into it? I plan to do it this off-season with a plumber buddy of mine. We both have young kids and this will be a multi-weekend \ month project. Do I need to worry about the inside rusting out or anything? Anything to be aware of when filling up, turning back on, testing?

As far as design goes I have the piping diagram for my boiler that was provided to me by someone on here. Everything needs raised to the 24" mark and I need to run the two mains off the side of the header from what I am reading. Do I have the right idea in my drawing with the red and blue designating the two mains and how I should run them? Also, someone said on here that my Hartford loop is wrong. I believe I should also be installing blow-down valves on the mains correct?. I think I also need to move my vents back from the ends of the returns a little. Any tips appreciated.

Also, where should I get my pipe, supply house? I need to find the blue pipe tape as well?













Comments

  • drewbert41
    drewbert41 Member Posts: 58
    Should I reuse some of the large piping above the water line? I wan't to replace everything below the water line for sure.
  • dopey27177
    dopey27177 Member Posts: 541
    The drawing shown is perfect and should be followed if you are willing to do the extra work.
    The boiler header looks too low in relation to the boiler water line.
    I prefer wet returns, if you are willing to install wet returns do them in type l copper using 95/5 solder.
    Follow the drawing even if you decide to use one riser off the steam header.

    At the Hartford loop use a close by extra heavy nipple.
    Very important insulate the steam main. Saves energy and will prevent excessive condensation which causes banging.

    Jake
  • drewbert41
    drewbert41 Member Posts: 58
    I have a bunch of insulation, but have been holding off. The drawing has everything on the right of the boiler and mine will be on the left.
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,485
    Check the diameter of the side outlet nipples from the boiler to make sure they are the correct size, or they will have to be removed, and enlarged, (check the installation manual for minimum sizes).
    The pipes/fittings are new enough so that they can be reused, if you can find someone to thread them for you. The local plumbing supply house may cut and thread new nipples bought from them, but maybe not the old ones.
    A drop header will make it easier to fit everything together as you go. Don’t apply the pipe dope with a trowel!
    The header should be bigger than the two outlets, if possible.
    Copper below the waterline will be best for the long run.—NBC
  • Steamhead
    Steamhead Member Posts: 14,515
    edited May 17
    On that boiler, I would make the horizontal portion of the header 3-inch. Those Dunkirks are notorious for wet steam, and the larger header would help dry it out. the two 2-1/2" risers from the boiler to the header are fine, but they need to be 24" high per the diagram. This also helps dry out the steam.

    Then pipe the steam mains individually as you propose, and the system will work much better. Don't forget to upgrade your main vents if you haven't already.
    All Steamed Up, Inc.
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
    drewbert41Hap_Hazzard
  • ethicalpaul
    ethicalpaul Member Posts: 3,022
    edited May 17
    You're going to love this project and it won't take very long if you have a plumber buddy. Get a 24" and a 36" pipe wrench from harbor freight if you don't have them already.

    supplyhouse.com is your friend. Blue monster tape is fine. Try to do all the near boiler piping with your existing pipe and fittings and then just order any nipples/fittings you need from supplyhouse.

    In my DIY experience, the trickiest part is the connection from the header to the equalizer. The rest is very straightforward with reasonable room for error. Getting a downward pitch on the header is an art form, but personally I don't worry if it's level.

    You can take up a lot of slack with "just one more turn" of any given pipe or fitting. If you need even one or two more turns after that, try it with pipe dope only instead of tape.

    https://forum.heatinghelp.com/discussion/181981/new-boiler-install-edit-passed-inspection
    1 pipe Peerless 63-03L in Cedar Grove, NJ, coal > oil > NG
    drewbert41
  • mattmia2
    mattmia2 Member Posts: 3,176
    does that enormous boiler match the edr? if it is like double the size it should be, might think about going with the right size of you are going to go through all the work of repiping it.
  • drewbert41
    drewbert41 Member Posts: 58

    Check the diameter of the side outlet nipples from the boiler to make sure they are the correct size, or they will have to be removed, and enlarged, (check the installation manual for minimum sizes).
    The pipes/fittings are new enough so that they can be reused, if you can find someone to thread them for you. The local plumbing supply house may cut and thread new nipples bought from them, but maybe not the old ones.
    A drop header will make it easier to fit everything together as you go. Don’t apply the pipe dope with a trowel!
    The header should be bigger than the two outlets, if possible.
    Copper below the waterline will be best for the long run.—NBC

    Thanks, Copper sounds great.
  • drewbert41
    drewbert41 Member Posts: 58

    You're going to love this project and it won't take very long if you have a plumber buddy. Get a 24" and a 36" pipe wrench from harbor freight if you don't have them already.

    supplyhouse.com is your friend. Blue monster tape is fine. Try to do all the near boiler piping with your existing pipe and fittings and then just order any nipples/fittings you need from supplyhouse.

    In my DIY experience, the trickiest part is the connection from the header to the equalizer. The rest is very straightforward with reasonable room for error. Getting a downward pitch on the header is an art form, but personally I don't worry if it's level.

    You can take up a lot of slack with "just one more turn" of any given pipe or fitting. If you need even one or two more turns after that, try it with pipe dope only instead of tape.

    https://forum.heatinghelp.com/discussion/181981/new-boiler-install-edit-passed-inspection

    Thanks I appreciate it. Any advice for how long it can be apart\ rust \ tips for success when firing it back up?
  • drewbert41
    drewbert41 Member Posts: 58
    mattmia2 said:

    does that enormous boiler match the edr? if it is like double the size it should be, might think about going with the right size of you are going to go through all the work of repiping it.

    I am not sure. It is only 6 or 7 years old maybe. We have 4,000 sqft and lots of pipe.
  • ethicalpaul
    ethicalpaul Member Posts: 3,022



    Thanks I appreciate it. Any advice for how long it can be apart\ rust \ tips for success when firing it back up?

    It can be apart for years :) Don't worry about rust, it will happen where it happens.

    For firing it up, make sure your main venting is in order, have a low pressure gauge like 0-3 psi, have your pressuretrol set at .5 cut in (for the common additive type) and tell the thermostat you want it 3 degrees warmer than the current temperature. This will give you a nice long fire cycle to watch.

    When you start, have the water below the level of your LWCO to make sure it "sees" the low water condition and refuses to start up your boiler. Then add makeup water to the normal water level to see if the LWCO then allows the boiler to fire.

    If it were me, I'd also put Maid o' mist #4 on all the first floor radiators, and #5 on all the second floor radiators as a starting point. ($9 at suppyhouse). I'm assuming you have 1 pipe steam.

    Watch the pressure as it starts to boil. You should see it go up just slightly. You should hear or feel air escaping from the main vent during this time. The pressure should be like 1/4 psi or less. Hopefully no leaks at this point! I see your main vent is all the way back at the boiler. This is OK but I like it better when it's just past the last radiator supply pipe.

    Follow the steam (by gingerly touching) as it heats up your main(s). Follow it to the main vent(s). See that the main vent(s) close against steam and don't leak after they get "steam hot". Look at the pressure as this happens. You should see it go up slightly as the main vent(s) close and the air starts to get pushed exclusively out of the radiator vents. Look and listen for any leaks in your new connections. If the pressure rises during this phase beyond like 1/2 psi your boiler is likely oversized. It's not the end of the world.

    Now start to run around to the radiators. This phase is long so you don't have to run too fast. See if the radiator vents are letting air out. It should be very slow venting. Hopefully all radiators should start to see steam at their supply valve at around the same time. The radiators will start to heat up from the supply side.

    Periodically run back downstairs (or have your helper on the phone) to see what the pressure is. Hopefully it will remain nice and low during this phase, below 1/2 psi (mine is at like 1/50 psi -- 1/2" of water column, but many boilers are oversized so they run higher psi while they are filling the radiators).

    If the pressure does start to build above 1psi now is your chance to really listen for leaks (you may not see them on the near boiler piping because there's a lot of heat and the steam may just evaporate off without condensing on the piping, but you might find a drip). Depending on the size of your boiler, pressure might rise up to the cutout point. Keep track of how long the cycles are if it does this to report back.

    Check the radiators again to see if they are all getting hot. See the thermostat get satisfied and see the boiler turn off. That's how I do it.
    1 pipe Peerless 63-03L in Cedar Grove, NJ, coal > oil > NG
    BobCCanucker
  • drewbert41
    drewbert41 Member Posts: 58



    Thanks I appreciate it. Any advice for how long it can be apart\ rust \ tips for success when firing it back up?

    It can be apart for years :) Don't worry about rust, it will happen where it happens.

    For firing it up, make sure your main venting is in order, have a low pressure gauge like 0-3 psi, have your pressuretrol set at .5 cut in (for the common additive type) and tell the thermostat you want it 3 degrees warmer than the current temperature. This will give you a nice long fire cycle to watch.

    When you start, have the water below the level of your LWCO to make sure it "sees" the low water condition and refuses to start up your boiler. Then add makeup water to the normal water level to see if the LWCO then allows the boiler to fire.

    If it were me, I'd also put Maid o' mist #4 on all the first floor radiators, and #5 on all the second floor radiators as a starting point. ($9 at suppyhouse). I'm assuming you have 1 pipe steam.

    Watch the pressure as it starts to boil. You should see it go up just slightly. You should hear or feel air escaping from the main vent during this time. The pressure should be like 1/4 psi or less. Hopefully no leaks at this point! I see your main vent is all the way back at the boiler. This is OK but I like it better when it's just past the last radiator supply pipe.

    Follow the steam (by gingerly touching) as it heats up your main(s). Follow it to the main vent(s). See that the main vent(s) close against steam and don't leak after they get "steam hot". Look at the pressure as this happens. You should see it go up slightly as the main vent(s) close and the air starts to get pushed exclusively out of the radiator vents. Look and listen for any leaks in your new connections. If the pressure rises during this phase beyond like 1/2 psi your boiler is likely oversized. It's not the end of the world.

    Now start to run around to the radiators. This phase is long so you don't have to run too fast. See if the radiator vents are letting air out. It should be very slow venting. Hopefully all radiators should start to see steam at their supply valve at around the same time. The radiators will start to heat up from the supply side.

    Periodically run back downstairs (or have your helper on the phone) to see what the pressure is. Hopefully it will remain nice and low during this phase, below 1/2 psi (mine is at like 1/50 psi -- 1/2" of water column, but many boilers are oversized so they run higher psi while they are filling the radiators).

    If the pressure does start to build above 1psi now is your chance to really listen for leaks (you may not see them on the near boiler piping because there's a lot of heat and the steam may just evaporate off without condensing on the piping, but you might find a drip). Depending on the size of your boiler, pressure might rise up to the cutout point. Keep track of how long the cycles are if it does this to report back.

    Check the radiators again to see if they are all getting hot. See the thermostat get satisfied and see the boiler turn off. That's how I do it.
    Awesome tips thank you. I have never had any pressure issues. Always stays super low. Proper near boiler piping should help that even more I would think. I like what you said about the main vents and will have to look into that. My vents at the radiators are all ok. I assume I will have to skim quite a bit afterwards as I am sure I will knock a bunch of crap loose in the pipes when I cut them.

    Will adding a bigger header and changing how the mains are run require me to mess with the pressure or can I leave it how it is?
    EzzyT
  • ethicalpaul
    ethicalpaul Member Posts: 3,022
    Knocking things loose won't require skimming. That stuff will find the lowest point. What will require skimming is the oil from your new pipe and fittings. After it's been running for a few days to a week, give it a skim.

    A different sized header and changes to the mains layout won't require you to change anything about your pressure. Congratulations on your low pressure, it's a nice condition to have.
    1 pipe Peerless 63-03L in Cedar Grove, NJ, coal > oil > NG
    drewbert41
  • drewbert41
    drewbert41 Member Posts: 58
    edited May 31
    Does the lowest part of the drop header need to be 24" above the waterline? I am trying to do something like this picture and I am looking to buy 24" nipples and drop from there. Do I need to use a union and go higher? I have room to go higher and still drop under my flue pipe.

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 9,112
    @drewbert41

    The lower part of the drop header only needs to be above the water line but I wouldn't put it below the top of the boiler jacket in my opinion.

    24" from the water line to the bottom of where the riser turns horizontal before it drops down into the header (higher is better) if you have the room
    drewbert41ethicalpaul
  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,356
    Figure out how many unions you're going to need for the wet return and start shopping around. Also think about where best to put them. If you can put them on vertical pipes above the water mine they'll last longer.
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
Sign In or Register to comment.

Welcome

It looks like you're new here. If you want to get involved, click one of these buttons!