Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Baseboards not heating up

lbeachmike Member Posts: 177
Hi -

I have a hot water baseboard heating system. Thermostat is working. Boiler fires on. I feel vibration on the circulator, but I don't hear the water circulating into the baseboards.

What could I check? Or is this just 99% likely to be a bad circulator?




  • Alan (California Radiant) Forbes
    Check your pressure. If it’s OK, you may need to purge the system of air. 
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • lbeachmike
    lbeachmike Member Posts: 177

    Check your pressure. If it’s OK, you may need to purge the system of air. 

    Thanks. Check the pressure via the pressure gauge or test the expansion tank directly? How easy is it to purge the system of air?
  • HomerJSmith
    HomerJSmith Member Posts: 2,441
    edited March 11
    More information is required. Is this a recent problem? What make of pump? Do you have coin vents on each baseboard? Was any work done on your sys lately? What does your boiler gauge show? What is the make of your boiler? How many zone valves and make?
  • Intplm.
    Intplm. Member Posts: 1,949
    edited March 11
    In order to help you. Some pictures will be needed to see what you have.
    So far it seems like you have no, or little water in your system. Not good.
    Your gauge on your boiler should read around 12-15 psi.

    Do you hear any noise at all from the radiators when there is a call for heat? Like a piggy bank loose with change.

    Please post some pictures of the gauge, piping near the boiler, and some radiators.
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,834
    edited March 11
    When I walk into a service call I check lots of things visually even before I enter the home. I like to look at the chimney from far away to see if there might be a problem with the draft. I listen to how long it takes for the burner to fire. Is the pre-purge (if any) too long? Oil fired equipment has many nuances that can point me in a certain direction. Gas boilers have different situations. Is the boiler water hot? Is there a flame in the combustion chamber? Are the pipes to the pump cold but the pump motor hot? With this experience I can decide to look at the electrical controls or the water side or the burner and combustion side of the system.

    Without the experience of being there on site, we are going to need answers to many questions and we don't even know what questions to ask yet with the limited information you have provided. Please bear with us as we try to help. Some questions will be better answered with photographs of your boiler, how the pipes are connected to the boiler and the radiators What valves are located where and what kind of pump moves the heated water through the system.

    Sometimes your answers will tell us that you are better off with professional help. Other repairs are definitely DIY friendly. Please don't take offense to anyone that recommends professionals because you are literally playing with fire inside your home. We don't want you to make a dangerous mistake.

    Lets start with the brand of boiler, and the model number. This will tell us a lot. Also how many zones do you have? Basically how many thermostats are in the home. If you have only one room thermostat then you have only one zone. And finally, does the same burner provide you with heat in the rooms and the hot water you use for taking a shower? or do you have a separate water heater?
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics