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A little banging

My dog was pacing back and forth. Something was wrong in the basement. Then I heard it. Banging and popping in my hydronic boiler. Rushed downstairs and shut the boiler down. Still popping. The temp on the gauge close to 220,but I know the temp on the gauge is incorrect so it was likely only 210. Infared tested only 200. Turned the aquastat down so the burner would not kick in and turned the thermostat up. Circulation pump is very quiet. 2nd floor returns are hot. 1st floor returns strangely cool. Circulator must be bad. There is power to it. Great. It is Sunday and the temp is going to get -20f. Heatpump sure is not going to work at these temps. Its a good thing I have a couple electric baseboards installed an electric fireplace, 2 oil filled heaters and an edenpure knockoff. Kept the house at 55-60 degrees. Now to get that pump replaced hopefully by Tuesday. Only going to get to -12 tonight.
coming to you from warm and sunny ND


  • JUGHNEJUGHNE Posts: 5,579Member
    What pressure is showing on the boiler?
  • jacobsondjacobsond Posts: 31Member
    Pressure was 20. Pump was humming a little but obviously no flow with cold return on 1st floor. Must have been running on gravity only. It's a cast iron crown boiler no sign of water loss.
    coming to you from warm and sunny ND
  • ZmanZman Posts: 4,814Member
    I would double check the integrity of your operating stat and high limit. I am suspect of the pressure gauge and PRV as well. You likely did see temps upwards of 220 if it boiled under pressure.

    Most small wet rotor circs have the same ~6 5/8" flange to flange measurement. Almost any model will get you by in a pinch.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • jacobsondjacobsond Posts: 31Member
    I ordered the same taco 007-F5 that has served me well for 19yrs. It should be here today. I hope the rusty bolts dont give me to much trouble.My temp/pressure gauge needs replacing and I thinking about changing the aquastat also. Just trying to get it running now. Its got a L8148A aquastat in there now. When looking for it there seemed to be a few choices. Its a Crown CXE-5 LP if you have any recommendations on which one to use. When it warms up enough to run my heatpumps for heat I can maybe do some better maintenance.
    coming to you from warm and sunny ND
  • SuperTechSuperTech Posts: 938Member
    Get a L7224U universal digital aquastat by Honeywell. Works great for replacing any mechanical aquastat and you can operate outdoor reset if you get the seperate module. I use this setup and have been happy with it.
  • jacobsondjacobsond Posts: 31Member
    Can that one be used with a gas boiler? Description says oil.
    coming to you from warm and sunny ND
  • SuperTechSuperTech Posts: 938Member
    > @jacobsond said:
    > Can that one be used with a gas boiler? Description says oil.

    Absolutely it can! Just wire a 24 volt transformer to B1&B2. Works like a champ! The only aquastat I need to stock on my truck now.
  • jacobsondjacobsond Posts: 31Member
    Well I got the circulation pump in. I only had to cut off 2 bolts. Everything working great. I went to bleed a couple radiators and the temp spiked again. No power to the circulation pump now. Contacts on the aquastat look a little black. Darn it was the aquastat that was actually bad. Intermittent power to the circulation pump. I wired the pump to run all the time ordered that L7224U that should be here by Friday. I should be ok till then. Looking at it now I should bite the bullet and order the draft inducer and the intermittent pilot spark module and just get all the control systems new. I replaced the gas valve this fall hoping that's all I would need. Well there has been no problems since I put this in in 2000 so I have gotten by pretty good. Thanks for all the help.
    coming to you from warm and sunny ND
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