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Replacement Taco 007 F5 suddenly buzzing

So I am visiting home for the holidays and just in time for my arrival the circulator pump on the boiler started making a loud buzzing sound.

The boiler is a 3 year old Bryant.  The guy who did the install came out and replaced the Taco 007 F5, which was under mfr. warranty, with a second identical pump (which cost $170 for 2 hours of labor).  Now 1 week later the replacement is buzzing.  You can feel the pump vibrating when you touch it and the buzzing can be heard in every room of the house since it is transferred through the pipes.

Any ideas on what could be causing this?

Some info:

1. 3 year old install, pump replaced 1 week ago

2. 7 radiators total

3.  1632 sq. ft. house

4. I bled all the radiators this time and last time, no change

5. ***A radiator which never got hot on the first floor is suddenly hot today since the pump has started buzzing.  This radiator was only ever luke warm before.  This makes me wonder if there is some weird air thing going on.  When the guy replaced the pump a week ago he didn't drain the system or bleed the rads.  He isolated the pump with the shut-off valves, drained that portion, replaced the pump, and done.


  • WeezboWeezbo Member Posts: 6,232

    why not replace the cartridge?
  • ZmanZman Member Posts: 3,476
    Wiring issue?

    It kind of sounds like a wiring issue.

    Maybe the pump relay is making bad contact.

    Is the pump extremely hot?

    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • red1281red1281 Member Posts: 5
    Yes very hot

    The pump is very hot to the touch.  Can't keep fingers on it for more than 1/2 second.
  • ZmanZman Member Posts: 3,476
    Not normal

    It sounds like they need to give it another looks.

    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • PLUMMERPLUMMER Member Posts: 42
    Valves closed

    Can do this, but you obviously have flow. A no flow will heat the pump up like that. Or little flow. How's the pipe temps up and down stream of the taco? Did he try to see why the last one failed, cuz its unusual for a 3 yro 007 to go when no other cause can be found.

    I hate to ask but how's the motor shaft placement? Horiz or vert
  • red1281red1281 Member Posts: 5
    edited December 2013

    It is installed on vertical piping with the motor shaft horizontal.

    The boiler guy stopped by today for a few minutes to listen to the sound and tried to say that the sound "wasn't that bad" (even though you can hear it throughout the house and it never sounded like this before) and said something about how the guy at the distributor will be mad about replacing all these pumps.  Boiler had been off and he could only stay a few minutes so he is coming back tomorrow to feel how hot it is when it has been running.

    I asked him if he thought air in the system could be a problem or if there could be an electrical problem and he said no.  He said he "didn't know" what the problem is and that it could be that we had bad luck with the parts.

    The first pump sounded like this when it failed:

    The second one sounded like that after about 1 week but has become quieter over the last few days.  It is loudest when first turned on then becomes quieter.  It is still extremely hot to the touch.
  • billbill Member Posts: 429
    My first thought...

    Hi Red- Is the cold fill pressure high enough? The pump could be cavitating itself to death.
  • Paul48Paul48 Member Posts: 4,228

    he inspect the impellor of the last one for damage? I'd try wiring it directly to another power source. Even if it meant sacrificing an old extension cord, to eliminate that.
  • red1281red1281 Member Posts: 5
    edited December 2013

    Boiler guy was back today


    He let a couple buckets of water out of the boiler drain and let it refill.  The boiler filled back up and then stopped filling normally.  The pressure gauge reads normal.  The boiler was hot when he did this but he turned it off.


    I don't know what kind of inspecting he did on the old pump.  He replaced the entire thing.


    After doing the water draining described above he tested the voltage at the boiler and said it was in the 150s.  Then he tested some outlets in the basement and said they are in the 150s as well, which is abnormally high and he said could be burning out the pumps.  So I called the power company and they sent a guy out 45 min later and he measured all the voltages at the meter outside, at the breaker, and at the outlets as normal (~240/120V).  He also said the transformer would trip if it was sending voltage that high and questioned the boiler guy's meter.

    I put the power company guy on the phone with the boiler guy and then the power guy said they would put a 48 hour monitoring device on the meter outside after the new year to rule out power issues.

    By then I'll be out of town again.  Barring any problems with the electricity, which I kind of doubt, I don't think the boiler guy knows what the problem is and he doesn't want to replace the pump again.  I'd like to get a 2nd opinion from another boiler guy but we'd have to pay another guy, while we don't currently have to pay the current guy since he just replaced the pump and it is acting up again.  Thoughts?
  • Total1Total1 Member Posts: 27
    check the power at the main panel

    Hello : check the power at the main panel  , sounds like you have a bad neutral . or even a loose neutral ..
  • red1281red1281 Member Posts: 5

    The power company guy said the neutral in the breaker was working.
  • 0409004090 Member Posts: 142
    edited December 2013
    Are you saying that

    the power guy looked at the breaker and said neutral is running through it OK?  Any splices the the cable, or does the cable going to the boiler go through any electrical boxes?

    Burned out a bunch of lightbulbs recently?

    You posted:

    The power company guy said the neutral in the breaker was working.

  • Paul48Paul48 Member Posts: 4,228

    there isolation valves on either side of the circ, or did they have to drain the system to replace the circ? Here's my line of thinking....stupid as this sounds...did someone leave a pencil in a pipe? The sound could be the vanes of the impellor hitting something. That's why I asked if he inspected them.The sound could also be created by a power pulsing. That's why I said to hook the circ up to another power source, temporarily.The latter could be done in about 5 mins, and would eliminate power as a possible problem.
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