Banging in baseboard


I have a Laars Mini Therm that started making loud banging noises. The house was heating but now the banging has gotten louder and the baseboards are not getting hot. I turned the system off and basically my family is spending Christmas in a freezing house with a few electric heaters and a fire place.

I do have a video taken on my IPhone is it would help.

The model number is: JVT125NDII

Is this Air? A Pump gone bad? Can I fix this myself or does it require a professional? How much do you think it might costs?






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Tom 4 years 3 Answers 670 views 0

Answers ( 3 )

  1. Do make sure your fresh water supply the boiler is open. What does the gauge read?

  2. Hi Dominick,


    Thanks for your quick reply.

    I have been bleeding the system for air and the noise seemed to be getting better, however the heater had been short cycling, and now it is not coming on at all. The pilot light is lit.

    I thought I was making headway. There were air bubbles occasionally coming to the top when it was running. I tried to only have the valve open when it was running.


    Now I’m trying to figure out how to get it to start back up. I only bled about 5 gallons over 30 minutes. The manual says short cycling is caused by too little water supply.


    Hope that all make sense.


  3. Hi Tom, Tom sounds like you just have air in the system. Try bleeding it first. Also the the expansion tank could be bad as wel. But first try to remove the air.

    What does the gauge read? Use the link below

    Remove air

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