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Heating boiler problem

scottd907
scottd907 Member Posts: 8
So ran out fuel, filled... reset boiler... started just fine but was only heating 1 out 2 zones. Thought it might be thermostat problem with zone 2. New batteries didn’t seem to help.
Both zone lines into house feel hot. Zone 1 was working and turning on boiler once temp dropped below temp.
Now the boiler is shutting its self off before zone reaches temp.
Looks like boiler internal thermostat is set to 190 and reaching 220 before shutting itself off.
So are my zone pumps bad? Can both them go out at same time? I mean I still feel little heat coming out zone 1 radiators, but no heat out zone 2.
Scoot

Comments

  • Zman
    Zman Member Posts: 7,132
    190 to 220 is very hot.
    Water boils at 212 at sea level, if 220 degree water is not under pressure, it flashes to steam. This is often a violent event. I would suggest running the boiler in the 180 degree range
    Those temps should be lower.
    It sounds like a zone pump issue. Do you have pictures?
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • HVACNUT
    HVACNUT Member Posts: 4,358
    How long was the boiler down before you got oil? Freezing temps where you are? Zone could be frozen. If you think the zone might be frozen, try to track down where and hit it with a hair drier.
    DZoro
  • scottd907
    scottd907 Member Posts: 8
    I’ll try to post some pics later on.

    I’m in the SE area of Alaska, temps have been pretty warm lately. Hasn’t dropped below freezing, least not while the heat was down. Was only down for a night and maybe half a day.
  • HVACNUT
    HVACNUT Member Posts: 4,358
    Get some shots from all around the boiler standing about 10 feet away. Pretty weird this happened the same time it was OOO.
  • CTOilHeat
    CTOilHeat Member Posts: 54
    Low water? Sometimes when a boiler is off and cools it leaks from various places. May have lost water/let in air.

    You may have a circulation issue now. That may also explain the high temps the boiler hits.
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 11,172
    The first picture shows a red handle ball valve that is closed. I suspect it should be open but can't see what it feeds to be sure.

    I suspect your boiler control is misbehaving. The high limit is set to 180 which is oh but the boiler temp is over 200.

    Those controls can overshoot a little but 20 degrees is a little much.

    @Zman said the water will boil and make steam...it won't the water is under 15 lb pressure. Your water pressure is ok.
  • scottd907
    scottd907 Member Posts: 8
    The leveler in the top of the picture? Yeah there’s a heater for the garage above the boiler, but unused.
  • HVACNUT
    HVACNUT Member Posts: 4,358
    First, the 68 series WM is notorious for overshooting the set temp.
    There's only one circ and zone valves for each zone. There's a lever on each. If the lever moves freely, the valve is open and that zone should be heating, unless it airbound or a bad end switch in the zone valve.
    To clarify, are you having problems with all zones or just one?
  • Zman
    Zman Member Posts: 7,132
    @EBEBRATT-Ed
    Water at 12PSI will boil at 242 degrees. At 220 degrees it needs to be under about 3 PSI.
    It is a bad idea to have water under pressure at a temp higher than atmospheric boiling point. If the pressure is released things get fairly ugly....
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • SeymourCates
    SeymourCates Member Posts: 162
    @Zman

    One other point to note is the fact that a setting of 12 psi on the gauge is only the pressure at the gauge. Depending on how its piped (usually badly), the pressure ahead of the circulator could be all the way down near zero. Your caution is wisely stated.
  • hot_rod
    hot_rod Member Posts: 15,423
    And, under the right conditions you can pull a negative, sub atmospheric condition on the suction side of a circulator. Then you are lowering the boiling point below the 212 at sea level.

    This happens occasionally with unpressurized OWF that have heat distribution above the water level.

    Here are three common conditions related to PONPC.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Jamie Hall
    Jamie Hall Member Posts: 17,813
    May I add that pulling the pressure on the suction side of a pump down to near the boiling point at that pressure -- whatever it is -- will lead to cavitation at the inlet to the impeller of the pump, which will destroy the pump in short order.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • scottd907
    scottd907 Member Posts: 8
    > @HVACNUT said:
    > First, the 68 series WM is notorious for overshooting the set temp.
    > There's only one circ and zone valves for each zone. There's a lever on each. If the lever moves freely, the valve is open and that zone should be heating, unless it airbound or a bad end switch in the zone valve.
    > To clarify, are you having problems with all zones or just one?


    There is heat upstairs. So 1 out 2, waiting to get a volt meter from work to check what my circulation pump is doing.
    I did move the zone valve from auto to manual. There was no resistance in the leveler and when I check the working upstairs zone valve, it had resistance to it. So I’m little confused if it’s the zone valve... would it allow the pipe on both sides of the valve to be hot? And both return lines are cold, one colder then the other but neither warm or hot.
    Would the circulation pump be maybe working a little, heat is upstairs, just not downstairs. If I set my thermostat for example to 75 and actual is 70. And I hear boiler kick on and then back off. Yet the temp hasnt reached the set temp. So even after the boiler shuts off the burner, it still should be moving water right?
  • HVACNUT
    HVACNUT Member Posts: 4,358
    Raise the thermostat on the upstairs. Check if both return pipes at the boiler get smoking hot. If you know which is downstairs, all the better. If downstairs gets hot when upstairs is running, it's a bad end switch in the zone valve. If the downstairs pipe does not get hot, then there's air in the zone and needs to be purged.
    Post a pic of the boiler from about 10 feet away, and the zone valves from about 4 feet away.
  • scottd907
    scottd907 Member Posts: 8
    So from my understanding is by moving the leveler from auto to man allows the circulation pump to move heat into that zone even if the thermostat isn’t calling for heat?
    Because Iv done that and still no heat in down stairs.
    One of my zone valves is marked up, so I’m guessing that’s for upstairs.
    Even been trying to check the return lines to see which is warmer then the other as the boiler is running. They T into one line in the back the boiler. But I’ll check each one and get you a answer for that.
  • scottd907
    scottd907 Member Posts: 8
    Alright there’s front about 10ft away and the 2 zone vavles.
    I’m fortune enough to have a friend that fixes boilers and furnaces for a living that thinks it’s my pump or Aquastat that’s gone bad. But the pump is working if I’m getting heat upstairs right? I just don’t understand why sometimes it reaches the set thermostat set temp and sometimes it doesn’t? Air locked and a bad pump?
  • Paul48
    Paul48 Member Posts: 4,470
    Just a thought........with the pump not working, it may be possible that the upstairs is getting convective flow. Whereas the downstairs would not.
    rick in Alaska
  • HVACNUT
    HVACNUT Member Posts: 4,358
    Turn down the thermostat for upstairs. Turn up the thermostat for downstairs. In the aquastat, there's a little grey relay clapper that should pivot a little out with a heat demand. Try to push it in. If it goes in and pops back out by itself, the circuit is complete and the zone is probably air bound.
    Above the circ are 2 valves. Keep the upstairs off and downstairs on. Close the valve just above the circ and open the drain valve above that into a bucket. Use a hose if you have one. Let the water and air drain out (It will be under pressure so be careful) until the piping above the drain valve gets very hot. Close the drain valve, open the valve above the circ and see if the pipe continues to stay hot. Set both thermostats to your comfort level.
  • unclejohn
    unclejohn Member Posts: 1,751
    I'm sure you know this but you have to push the lever and then lock it in for it to stay manually open. I know you know that.. I'm just trying too catch Mr. Hall on posts.
  • scottd907
    scottd907 Member Posts: 8
    Alright I bleed the lines once, I think i might need to again.
    I think Iv narrowed it down to my Aquastat or circuit board. Testing the power from the board to the power read 0 volts. No power turning on the pump when thermostat are calling for heat. As soon as I connect my pump to a 120volt power supply, water starts moving through the lines.

    I know have heat in the downstairs zone, the one that wasn’t working. But it sounds like I might still have some air in the lines. Almost like a faucet running in my radiators
  • HVACNUT
    HVACNUT Member Posts: 4,358
    What's the low side setting on the aquastat?
    What board are you talking about?
    What are you using for domestic hot water?
    Hard to believe upstairs is heating fine if the circ is dead, even with a gravity rise.