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Weil-Mccain Poor Performance

Smith19 Member Posts: 95
Hello everyone -

This fall, I am house sitting for my grandmother, as she has moved into assisted living. The house is on the market currently. I know the house well as I grew up in the region, and in 2013 I helped her choose a boiler when the old one failed. It was a standard set up for a 1987 New England builder-grade house. New Yorker steel boiler, hydronic, baseboard, four zones, and a Beckett AFG. The only thing "luxurious" about the system was the HX Hostow indirect fired water tank. She wound up settling on a Weil-McLain WGO-4 installed with a Beckett AF and digital Hydrostatic. A Weil-McLain stainless hot water storage tank was also installed. We have always had an issue with a puff of exhaust on startup, going all the way back to 1991. We assumed it was a flue thing as the oil company always told us that it was normal. With the new boiler it's just as bad if not worse. A loud "BOOM" is heard on ignition, and one time I rushed downstairs to see smoke hanging in the basement like an old western saloon. Oil company continues to tell me this is normal -"cold flue" and all that. But the service man who came by recently didn't clean out the flue pipe or even change the oil filters - something that makes me question his judgement. "It's a new boiler so it doesn't really need it" he says. Sure.

I am concerned about air quality as I don't want to wake up to a puff back late one night, especially as the weather gets colder.

Some extra info that should help:

-Beckett AF with SenSys control system and pre-purge (solenoid valve over pump)
-Rear flue connection to a 45 degree run of pipe to the breaching with the chimney
-Barometric damper is set for horizontal run
-LOTS of soot and ash on floor under barometric damper
-LOTS of Kibbles and Bits found in firebox during the cleaning

I would like to start by increasing pre purge time on the burner, but I understand that this is a factory pre-set and requires some sort of fancy tool to change. I have also heard that a Carlin EZ-1 is the best burner for this set up. Any Thought? Photos are enclosed. Thanks!


  • KC_Jones
    KC_Jones Member Posts: 5,081
    You need to find a qualified tech to clean the boiler and tune the burner for proper operation with proper combustion analysis equipment.

    Also never ever let anyone from that company in the house again. They literally have zero clue what they are talking about.

    Where are you located? We may know someone good that services your area.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
  • STEVEusaPA
    STEVEusaPA Member Posts: 5,689
    I agree with @KC_Jones. If it were properly tuned it wouldn't do that. You don't really need to extend the pre-purge, 15 seconds is fine.
    Proper cleaning, tune up, and smoke & proper draft and you should be fine.
    That heat exchanger should not be that sooty black on a boiler that even though is cold start, probably is really a warm start. Tells me poor combustion and lack of combustion air.
    Also, I would make sure the fuel line is properly bled.
    I also suspect some back firing and lack of draft. Looks like the inspection door got cherry red hot at least once.
    That boiler is pretty notorious that if not properly cleaned very well, you get poor draft.
    BTW, is there a string or wire hanging from the barometric damper? If so, what's going on there?

    And I'm concerned about enough combustion air. Do you also have a nice high performance clothes dryer down there too?
  • Smith19
    Smith19 Member Posts: 95
    I am located in Marion, MA. The same company did a pretty piss poor job of maintaining the old New Yorker, as can clearly be seen.

    Boiler is not technically set for cold start - the hydrostat is set at a low limit of 154 degrees and the high limit is 182 with a 25 degree differential on the high.

    Should I open up the air cuff on the burner more?

    Nothing else in the basement sucks air - pretty good fresh air source because the bulkhead has some fresh air ventilation.

    As for the string - I have no clue. It's not attached to anything, just sort of hangs there. Doesn't make a difference as to how it operates, as far as I can see.
    HVACNUT Member Posts: 4,593
    edited October 2017
    Do not touch the air adjustments. More air will make it worse.
    You need the Genysis contractor tool to change programming. 15 second pre purge is fine.
    Was this an established fuel company that did the installation? Whoever did it is stuck in the 60's on proper boiler piping.
    Find a reputable fuel oil service company to clean and adjust the boiler and burner.
    The boiler and chimney base must be brushed and vacuumed.
    Replace the oil filter and pump strainer.
    Make sure the oil line is not restricted. If it comes off the bottom of the oil tank, there should be good gravity flow to the fuel pump.
    I don't know what the heat loss of the home is, but I'm going to take a guess and say the WGO-4 is oversized, along with the firing rate.
    Beckett specs a 1.25 80*B nozzle @ 100 psi pump pressure with an F4 head. Unless the house is about 3,500 sq ft with poor insulation, it's way over sized.
    See if THE EXPERIENCED Tech can downfire it to 1.00 GPH.
    After all is done, a smoke reading of 0, proper draft and a combustion analysis with a printed report must be done.

    O2 should be between 4-6%.
    CO2 should be between 10-12.5%.
    CO should be less than 50 PPM.
  • Smith19
    Smith19 Member Posts: 95
    Thanks for the info. Yes, the company that services it did the install in 2013. As for the piping, that was probably done by a sub-contractor in 1987. Piping wasn't changed in 2013. I don't trust the oil company for the reasons stated above.
  • newagedawn
    newagedawn Member Posts: 586
    edited October 2017
    must be hard to heat 4- 3/4 zones on a 1 inch pipe
    "The bitter taste of a poor install lasts far longer than the JOY of the lowest price"
    HVACNUT Member Posts: 4,593
    edited October 2017
    > @newagedawn said:
    > must be hard to heat 4- 3/4 zones on a 1 inch pipe

    Yeah, looks like a boiler swap out only, not a complete install.
    And they didn't even wire the water heater into the Hydrostat to make use of the boiler reset economizer.
  • Dave0176
    Dave0176 Member Posts: 1,172
    Where your located I’d call Steve Lavimoniere he’s a great oil burner guy.
    DL Mechanical LLC Heating, Cooling and Plumbing 732-266-5386
    NJ Master HVACR Lic# 4630
    Specializing in Steam Heating, Serving the residents of New Jersey


    I cannot force people to spend money, I can only suggest how to spend it wisely.......
  • CapeCodOilGuy
    CapeCodOilGuy Member Posts: 43
    edited December 2017
    Beckett AF?? Are you sure that's what it has? The AFG is the proper Beckett burner for a WGO, the AF doesn't generate enough static pressure. I personally prefer the Carlin EZ-1 for the WGO. Fitted with a 60200 or 70200 primary with pre-and post-purge, and dialed in correctly, they run clean and neat! In any case, 15 sec. pre purge and post purge is plenty for those. DON'T TOUCH THE AIR ADJUSTMENT! That should only be done by a qualified technician using the appropriate instruments. I would also strongly recommend installation of a Tiger Loop deaerator, mounted on the hinge (right) side of the boiler; with the flexible lines, it makes servicing much easier and eliminates problems caused by air in the oil. Whoever told you that a loud "boom" on startup, or smoke on startup, is normal should not be doing oil burner work. You need to have someone find out what is going on with your flue draft-in a big way!
  • CapeCodOilGuy
    CapeCodOilGuy Member Posts: 43
    Also-if your fuel line has the old-style fuel filter (where you have to remove the metal bowl and replace the cartridge inside), get rid of it and replace it with a 10-micron spin-on filter equipped with a vacuum gauge (gauge lets you know if the filter is starting to load up and need replacing). They do a far better job of keeping crud and sludge out of the unit. In my own house, I run a combustion check on my WGO-5/Carlin (usually reads close to the previous year's reading), and clean the boiler/change nozzle, filter, etc. every 3. Boiler is clean except for tan-colored ash.