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My Peerless M1 boiler fails but ONLY when it's very cold

ljaygouldljaygould Member Posts: 7
I own and live in a 12-year-old three-family house in Bronx, NY. The house was built with gas heat, PEX tubing, baseboard radiators. There are three apartments, three boilers. Alone among them, mine (ground floor) will predictably work fine until 1) the unit shuts off for the night, 2) the temperature goes below about 22 degrees Fahrenheit and 3) the system attempts to kick in. Control is from a battery-powered electronic thermostat that automatically turns the temperature to 62 at midnight, then up to 70 at about 7:30 AM.
I'm covered by a home warranty but by the time a repair person can get here, #4 in the list kicks in: The unit comes on just fine after the outside temp goes above freezing. They then are unable to find anything wrong with the system despite my description.
HELP! Thanks, guys (and gals), much appreciated.


  • Jamie HallJamie Hall Member Posts: 12,846
    When you say it "attempts to kick in" just what does that mean? If you look in your user guide (here, if you weren't given one or have lost it: on page 6, there is a sequence of events which the boiler should do. Where does it quit?
    Br. Jamie, osb

    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.

    Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • icy78icy78 Member Posts: 350
    WAG here. If nothing works below 22f.
    Someone wired up a warm weather shutdown stat (AND it's set wrong, )and landed on "open on fall of temperature" instead of rise of temperature.
  • HomerJSmithHomerJSmith Member Posts: 923
    edited February 21
    Is your boiler in a conditioned space? Is the vent motor operating correctly? Is the flue mostly exposed to the outdoors or does it rise in a conditioned space? Is your boiler getting power and gas when it get cold outside? Is your gas meter regulator operating correctly?

    You can remove the thermostat and touch the two wires together. Does the boiler operate properly when it is cold? Is there a junction box on the thermostat wire or such that gets cold and creates an intermittent connection?
  • ljaygouldljaygould Member Posts: 7
    Wow! Thanks so much for all the responses.
    Jamie: "Attempts to kick in": This was not well explained. Here goes...Usually, I wake up because my bedroom is very cold! I find the thermostat set to 62, the usual night-time temp...and I set it to 70 or 72. As it goes up, I hear the click, but there's no circulation of hot water through the system. That click = "attempt".

    Sequence of events: I wish I knew more. When I went downstairs Friday morning (yesterday) I checked the two pipes - the riser was significantly warm but not so hot I couldn't hold it (as it usually is). The return pipe was barely warm. I could feel the whir of (I think) the circulation pump but the radiator units in the house were cold. Everything kicked on just fine when the temp rose above I think 30 or so. I'm not sure exactly because I'm sitting there with my electric space heater in one room keeping me warm, at some point, I reach over and the radiator is hot.
    THANK YOU for the user manual! No, I don't have one (but do now!)

    Icy78: This sounds like a possibility. Checking the user guide linked by Jamie (just above your message), I don't find a reference to such a thing; it would be great if it was that easy. Can you tell me more about where I'd find it?

    Homer: The setup for my heating plant in this three-family house is in the basement, a finished space but not heated with baseboards etc. The house is a row house in the center of the row of five, and it generally doesn't get very cold. The units are in a separate room with a metal door (concrete outside wall, sheetrock inside). Each of the three units has an identical gas boiler and water heater (also gas). The room is not separately heated but the six units together generate enough heat that it's generally warm in there. Pictures being worth 10,000 words, let me take a couple and link them here: 1 boiler Peerless M1.jpg?dl=0 room all 3 apartments (mine on right).jpg?dl=0 gas boiler.jpg?dl=0 pipes in boiler room .jpg?dl=0 to outside.jpg?dl=0

    I really appreciate your coming here and helping me. I hope looking at the pictures isn't too much of an imposition; I reduced the size from my phone's original to make them smaller and easier to download.

    BTW, this problem is VERY predictable and VERY reproducible, if the required temperature is reached! I have a home warranty and had set up a service call when this happened last Saturday (19 degrees). The repair guy scheduled for Tuesday afternoon, when of course it was working. He didn't come but we were in touch by phone (we know each other from other calls and usually work well together). We agreed he'd come over Friday if I called and the 20-degree temp caused the problem to happen (which it did). I texted him and got a return text "sorry, out of town until tomorrow family emergency". (growl). Don't see any days like that in the weather pattern as far forward as it unless something here solves it we may be into NEXT heating season.

  • BillyOBillyO Member Posts: 186
    sounds like you also need a circulator pump
  • ljaygouldljaygould Member Posts: 7
    Interesting. So your theory is that the circulator pump is bad, or going bad, because it doesn't operate effectively in colder temperatures?
    Since it works just fine when the temperatures are moderate (like now when it's 47 degrees) it's going to be a tough sell to the home warranty company unless it gets very cold again (not predicted to go below 24 in next 10 days) AND I can get a service technician here to witness the failure (under 22 degrees).
  • STEVEusaPASTEVEusaPA Member Posts: 4,134
    edited February 23
    That venting is very suspect (probably illegal) and I see no provision for make up combustion air. The combination of vent hoods and motors is not good. I wouldn't even go into that mechanical room without my personal CO monitor on.

    Does the boiler start running immediately when you initiate a call for heat?
    If you're boiler is cold, normal operation may be no water circulates until the temperature comes up to the low limit setting on the aquastat. Then when the circulator comes on, the temp immediately drops, and the circulator shuts off. This short cycling repeats as the boiler gets warmer and warmer.
    Do you have a close up picture of your aquastat with the cover off?
    What happens if you just leave the thermostat at one setting for 24 hours or so?
    BTW, you can put the pictures directly in your post. Just drag it from your desktop and drop it into the post, or if on an IOS device, click the photo icon (rectangle icon with silhouette or mountain and sun) select 'Photos', or 'Camera Roll', select photo, then Save or OK.
  • ljaygouldljaygould Member Posts: 7

    Boiler room

    This room has been vetted by at least two master plumbers over time, and we have had the Fire Department here on one occasion when a tenant unjustifiably claimed a "gas smell". The vast majority of the copper piping was replaced between 2010 and 2016. BUT you're right, the builder did NOT cover himself with glory in the 2006-2007 building of this house which I purchased in 2008 brand-new.


    It would NOT surprise me if this component was either failed or defective or was simply not set correctly. I'm assuming that the wire that goes up into the ceiling of the room directly from that box goes to my thermostat. The other apartments have cuts in the wire where we can test the thermostat operation by directly attaching the wires; I'm guessing that the reason this isn't done here is that the handyman (who I had to fire in 2016 for unrelated reasons) had direct access to that one by walking upstairs to my apartment and clicking those wires together directly or by resetting the thermostat until there's a click.
    At your suggestion I took a few pictures of the aquastat:

    The legend on the knob isn't easily readable through the window on the case and, in any case, I have NO idea how this should be set. OR if it's working properly which it may well not be, since it's over 12 years old and its original installation was probably not the best!

    Again, thanks to all for chiming in on this, it's VERY appreciated.

  • ljaygouldljaygould Member Posts: 7
    It appears that there are only four pix allowed in a post; here's the one I tried to put in that greyed out the "Post Comment" button!

  • JUGHNEJUGHNE Member Posts: 6,895
    That control in your last pictures is not the controlling aquastat.
    It is a manual reset high limit safety. Have you ever had to push the reset button?
    Your controlling aquastat may be under one of the covers/doors.

    I don't see any zone valves that must open before the pump starts, so if that is the case then:
    if your pump is suspect to stalling until it heats up from being stuck, (it will hum even if not turning), You could wire it direct and run 24/7 to see if the problem goes away.
  • HomerJSmithHomerJSmith Member Posts: 923
    This ain't rocket science. The click you hear when you adjust the thermostat is just that, the thermostat? Sounds like a mechanical thermostat? What kind of thermostat do you have?

    If you have gas. If you have a pilot lit. If you have a boiler flame. If you have a circulator that is turning. You should have heat. Where is your failure in this sequence?

    I would begin jumping the safety switches at the boiler one at a time. I would start with the TT (thermostat) connections at the boiler. If you have a volt meter set to AC 24V, You can go thru the whole safety sequence and see if the voltage is continuous thru the whole circuit. The manual should have a ladder diagram showing all the safety switches.
  • ljaygouldljaygould Member Posts: 7
    Homer...thanks for coming back in and sharing that. The thermostat is electronic and programmable (battery-powered).

    THE ONLY FAILURE is a consistent one when the temperature is lower than 22 degrees. I am somewhat partial to answers that involve the Honeywell aquastat system (I say "system" because there's another box here:

    that gets the wire from the aquastat. SO...RIGHT NOW:
    1. I have gas.
    2. I have the pilot lit.
    3. I have a boiler flame.
    4. I have a circulator that is turning.
    ...and I have heat. NOW. It's 47 degrees in NY City right now! If it were 19 degrees having gone down during the day, the heat would stay on. If I deliberately overrode the thermostat that wants to automatically go down to 62 degrees at 12:30 AM and told it to stay at 70 or 72, it would stay on. What it will NOT do is come on from cold if the temperature is less than 22 degrees.
  • BillyOBillyO Member Posts: 186
    did you take thermostat off wall and jump wires together when temp is 22 or lower?
  • SuperTechSuperTech Member Posts: 1,329
    That doesn't make any sense at all. There's nothing involved with the thermostat or the aquastat that is affected by outdoor temperature. The problem has to be something else. Try using the hold function of the thermostat. Then it will not revert back to whatever it's set for in the programming. It will stay set at whatever setpoint you want.
    I'd like to see what the aquastat is set for. Can you remove the cover of the aquastat in the pictures above so we can see it's settings?
  • BillyOBillyO Member Posts: 186
    HAHA. that sounds like thermostat or am I reading that wrong fella
  • BillyOBillyO Member Posts: 186
    that was a genius remark big guy
  • ratioratio Member Posts: 2,428
    Unless I'm misreading, it sounds like you have a circulation issue that only occurs when it's below freezing and after a extremely large setback. Follow all of the pipes & see of any are in an a location where they might freeze. It wouldn't take much of an ice plug to stop water circulating. The next time it does it, feel the supply lines as far as you can reach them.

    It might serve to reduce (or eliminate) your setback, the thought being that the water won't sit stationary in the pipes as long, reducing the chance of freezing.

    BillyOSTEAM DOCTORSTEVEusaPArealliveplumber
  • BillyOBillyO Member Posts: 186
    great observation
  • HomerJSmithHomerJSmith Member Posts: 923
    edited February 24
    SuperTech, It's a matter of trouble shooting. I doubt that the temperature where the thermostat is or where the boiler is, is 22 deg at any time.
    However, the thermostat wire can run down the exterior of the wall where it is cold. By eliminating the thermostat and crossing the wires, one would eliminate the thermostat as a possible cause. Then one could jump the TT connection at the zone controller, then at the boiler aquastat.

    At 22 deg, the stack temp drops and the exhaust becomes heavy (lacks buoyancy) especially with a large stack size. Do you think that there is a spillage switch that gets tripped? Maybe something else in the safety circuit that is temperature sensitive?

    You got to start somewhere with your trouble shooting. Jumping the devices one at a time in the safety circuit is a logical place to start if there is power and a pilot working.

    Another idea, good idea Ratio, is that it is a water circulation problem? Perhaps a baseboard pipe runs close to the exterior of the building and the pipe freezes at that low temp and shuts off the flow.
  • JUGHNEJUGHNE Member Posts: 6,895
    I am thinking along Ratio's theory that it is a circulation problem.
    Trying constant circulation for a while might conquer the problem.
    Perhaps copper line too close to cold zone creating ice slug that eventually opens.

    OP has boiler firing but little to no water flow until OAT rises.
    IIUC, the only problem is no flow at 22 OAT.
  • Dan FoleyDan Foley Member Posts: 1,211
    I doubt outdoor temperature is causing the problem. You just notice it then because it is cold out and the problem is intermittent.

    Not enough information to troubleshoot over the internet. The first thing I would check is the L8148. If it is the “e” series, they were notorious for relay failure.
  • HomerJSmithHomerJSmith Member Posts: 923
    Dan Foley, right on. The vibration of the opening and closing of the circulator relay causes the solder foil pattern on the back of the board to crack which could be temperature sensitive. I've had that happen. An it would lead to an intermittent condition. Without that circulator relay, there ain't a goin'a be any pumping. No pumpin', no curculation, no circulation, no heat. I think I got that right.
    Dan Foley
  • Erin Holohan HaskellErin Holohan Haskell Member, Moderator, Administrator Posts: 1,306
    BillyO said:

    that was a genius remark big guy

    @BillyO, this comment doesn't help the discussion at all. You can disagree with people without being disrespectful and sarcastic.
  • ljaygouldljaygould Member Posts: 7
    Again...thanks for all the comments and help.
    I thought I DID open the aquastat and show the settings.
    Baseboards only run on interior walls - AND remember this is an interior row house so no baseboard actually runs on a wall that's exposed to the outside.
    L8148 - I'm assuming from my Google search that this is the aquastat relay I just showed in the last pic I put up, the box that's attached directly to the boiler? "Aquastat relay"? Since these two boxes (aquastat and relay) reach into the boiler and deal with the temperature I'm thinking there's some characteristic that happens when enough really cold air comes through the vent that is right above that boiler (NOT the other two in the room for Apt's 2 and 3) that sends a bad signal to the devices and causes some kind of cutoff. When the system misbehaves, remember, the pipes are warm and cool, not hot and a little less hot (normal when the water's circulating) as if the system is on standby. There's a whirring feel when I'm holding the pipes. I'm thinking that somehow the water temperature is affected by the cold air entering through the vent (which is RIGHT above the boiler) and the aquastat/relay is giving a wrong signal to shut down. I'm not sure whether this means reset the settings or replace one or both of those boxes.
    Remember also, this CAN be worked around by effectively setting the system to hold at 68 or 70 degrees rather than go down to the usual overnight temp of 62. I'm thinking that the cutoff controls in that aquastat/relay system are doing something bogus when the temp gets colder in that part of the room (not actually 22 degrees of course but whatever the low temp that happens in that part of the room when the thermostat is set low so the burner is not actively heating the water AND the room is being invaded by 22 degrees or lower coming in through the vent).
  • ratioratio Member Posts: 2,428
    How 'bout a pic of the circulator? Can you see/does it feel like it's turning? If it's trying to pump but no water is moving, that still sounds like a freezeup to me (although it could be something else). It's possible that a line runs through an under-insulated spot somewhere on its path—it wouldn't take a big air leak to cause circulation issues.

    Definitely check the aquastat too, though.

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