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Not enough time to get it all in one day, where to start?

aircooled81 Member Posts: 205
New boiler account. Large residence, 2 pipe system, vacuum/condensate return, thermostatic valves on all radiators, been running for a long time. Many hands in this cookie jar. Low pressure, peerless 211a
Boiler is filthy inside, despite monthly blow downs. Wet steam. Water hammer in some radiators and piping, but not all, and not all zones. Condensate pump floods the boiler. Haven't found out why pressuretrol is set to 4 psig yet. Traps have unknown service record. Gas train is a wonderful 2 stage assembly, but only wired for high fire.
I would love to make this system sing, bit overwhelmed, where is the best place to start? If I had to choose a days worth of issues to start with, would the filthy boiler and condensate return issue be best, or am I better off hedding into the system and tackling the water hammer and work my way back?


  • Jamie Hall
    Jamie Hall Member Posts: 23,289
    This is going to take more than one day! I'd clean the boiler first, and make sure that it is set to low pressure -- less than a pound, Get that straightened out. That won't take long (heh heh). Then take a look at the condensate return; it shouldn't need a pump (unless the piping is really seriously weird), so find out why it's there and figure out how to get rid of it.

    Then take a close look at all your near boiler piping. There may be some real problems lurking there.

    Then go out into the rest of the system and check every piece of pipe for slope, and fix those problems. Insulate it while you are at it, if it isn't.

    Fire it up and check and replace traps as required.

    This is just a very broad brush outline!

    You may find yourself getting detoured at any point -- but go for it. It can be done!
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Steamhead
    Steamhead Member Posts: 16,835
    You say this system has "zones"- meaning, motorized valves serving different parts of the house?

    How is the return pump activated- by a float switch in the tank, by a pump controller on the boiler or by vacuum?

    Have you noticed who made the original hardware in the system, such as Dunham, Hoffman or Webster?
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
  • aircooled81
    aircooled81 Member Posts: 205
    First of all, Thank you for the quick responses.
    - I would like a product recommendation for clearing mud from the boiler, soda will only change the ph, I'm going to need something to really work at that mud... any suggestions?
    - Vacuum system, I agree pressure can much lower at boiler. The pressurtrol only goes down to 2psig, before I replace it with a lower model, I need to find-out what was the purpose of 4" setpoint. But I agree, turning it down as soon as I can!
    - not ready to chuck the pump yet, they just replaced it. But I will certainly check out the piping, beutiful insulation job done on all supplies last year. Hate to cut it out to check slopes, but I'll do what I have to. Haven't crawled under the house yet. A Lot of square footage to cover, this place is huge.
    - excuse the 'zones' comment I made. All radiators are controlled separately, most by control valves at the radiator, the big radiators are controlled by electric valves below the floor. I haven't seen more than one radiator controlled by one valve.
    - The pump is controlled by 2 floats in it's receiver, and a pressure switch on the receiver. I have not pinned down the pressure it is trying to maintain, but it was newly installed last year and I'm not certain the floats were set correctly. It also does not have a vent tee at the top, just an inverted trap that runs the vent back to the drain (submerged into a sump slightly above the water level), so I'm already a bit skeptical of the installation.
    - System hardware. Hoffman 17C traps at all radiators (1 or 2 are 3/4" on the big boys, the rest are 1/2"), should all use the same element though. The control valves I did not recognize, might be danfoss thermostatic, pump is a very nice Bell & Gossett VLR system, Boiler is a peerless 211A - nice steam space high water content boiler I believe, mc donnel miller 51-2 LWCO/fill, Honeywell pressuretrol (one for set point, one for high limit).
    - near boiler piping, one problem pretty obvious but not sure if this is a deal breaker. The tappings on the boiler to the main header leave one from the upper left side, and the other from the top. They mate into a 6" horizontal manifold, but the qty 2 3" risers leave in the middle of the manifold (between the 2 boiler tappings. So I believe when they are both moving steam I'm likely getting a condensate puddle in the 6" manifold between the two vertical exit points.
    There is also a hartford loop which the condensate pump discharges into. No control or circuit setter valve on the discharge of the condensate pump, so I believe this might be splashing condensate up into the equalizer. The equalizer is off the end of the manifold and swung about 3' over before it drops down to the hartford loop. Not really pitched downward, almost level. Then the hartford loop (partially insulated as the entire equalizer is) looks as though the nipple may not be a 'close' nipple at the top of the inverted trap. Gonna have to remove some real pretty insulation to see this for sure.

  • Pumpguy
    Pumpguy Member Posts: 656
    Can't comment about the rest of the system, but may be able to shed some light on vacuum pump operation.

    First of all, for good vacuum operation, you need relatively cool condensate. 140 degree F. is a good number, but if much hotter, say 175 F. or more, it will be very difficult to reach the vacuum switch shutoff point.

    The usual settings on the vacuum switch are OFF @ 8" Hg., ON @ 3" Hg. vacuum. This switch is wired to operate the pump independently of the 2 float switches. Placing the switch's selector in the FLOAT ONLY position just blocks the contacts open, leaving the float switches to operate the pump.

    The receiver is divided into 2 compartments. The lower section is used for condensate collection and is at system vacuum. The condensate is then lifted by vacuum into the upper compartment. The lower float switch activates the pump to produce the vacuum to lift condensate into the upper compartment.

    The upper chamber is at atmospheric pressure. Condensate in this chamber recirculates through the centrifugal pump and nozzle venturi to produce the vacuum. Air removed from the system is discharged to atmosphere.

    The upper chamber water level is controlled by the upper float switch. As this level increases, this switch will open the discharge valve, sending condensate back to the boiler.

    Hope this helps your understanding of the vacuum pump operation
    Dennis Pataki. Former Service Manager and Heating Pump Product Manager for Nash Engineering Company. Phone: 1-888 853 9963
    Website: www.nashjenningspumps.com

    The first step in solving any problem is TO IDENTIFY THE PROBLEM.
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,576
    How old is this boiler?
    For cleaning the boiler, just follow the instructions from Peerless: a longish simmer with Arm&Hammer washing soda, followed by a long slow skimming, from their recommended port. As the skimming is such a long process, maybe they have a handyman who could learn to do it in between your visits.
    While you have the Peerless book open, show the owners the details of the Peerless "Mod-u-Pac" staged gas valves for hi-lo firing, as well as the recommended steam supply piping, which apparently has not been followed on this boiler. The table of pipe sizes for different capacities of 211A will enable you to know if the supplies are undersized, and therefore spraying water up into the mains.
    Once you have dry steam coming from the boiler, it will make the rest of the diagnosis/repair easier.--NBC
  • aircooled81
    aircooled81 Member Posts: 205
    Thank you all for the replies.
    The boiler is 4 to 6 years old.
    I was worried about the mud, didn't think washing soda would remove it.
    I have not returned, as the owner is chewing on the repair reconmondations and trouble shooting required. It's summer, he has a while to think about it before this boiler needs to be fired-up anyways.
    I was thinking about a water softner for the make-up water, we have very hard water out here, this hard-water is always making it's way in due to the frequent blow-downs and monthy flushing they perform.
    I explained the advantage of the mod-u-pak, and he is very interested. Peerless explained to me, high fire is first to create the draft required, then low-fire gives you a nice simmer.
    I am interested very much so in lowering the pressure, the presuretrol only goes down to 2 psig, so if I get the job to run the mod-u-pak, I'll likely get a 2nd presuretrol for the additional staging that has a range lower than 2 psig. maybe in ounces?
    There are some quirks to the piping, and i beleive over 20 condensate traps to check. I have not crawled the piping, and so there is along road ahead of me if I do get all the work I recomeneded.

  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,576
    The traps were probably failing, sooooo the system pressure was raised 4 psi to get steam moving, soooooo the water stacked up 5 feet in the returns, starving the boiler, soooo the condensate pump was added.
    This explains it all:


    This system should be returned to 6 ounce maximum pressure, with a vaporstat, verified with a 0-15 ounce gauge, and any non functional traps (radiator, and crossover) rebuilt.
    Supplying a boiler with softened water will introduce chlorides into the system, (see "graphitic corrosion"
  • Sailah
    Sailah Member Posts: 826
    edited July 2015
    If you want to pull all the cage units out of the Hoffman 17C and send them to me, I'll test them and report back which are failed. If you do pull them, mark each one with radiator location that way it could help locate problems.

    All the 1/2" traps will take the same cage unit, but the 3/4" are different.
    Peter Owens
  • aircooled81
    aircooled81 Member Posts: 205
    The quote was great!
    I can only imagine what other things out there other than traps that may have been neglected, removed or forgotten about. I look forward to poking around this summer, and maybe just maybe, get rid of that condensate pump.
    Thank you for the note about soft water, I'll do some more reading.
    Thanks for the offer on the traps. I have to rotate the pressure releif, it was installed on it's side (horizontal) but the manufacture said vertical only. This is where I was going to put it on the top of a tee, and then extended a nipple and valve out the other side of the tee for a trap tester. I will let you know how it went, if I get the work.
    great point btw, about labeling which trap came from which radiator.