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Basement radiators not working

johnnygoat Member Posts: 5
edited December 2020 in Radiant Heating
I have two 8 ft cast iron baseboard radiators in basement not getting hot. I had a couple of plumbers and heating contractors come out and install a purging valve and purged system and bled radiators and still not hot. I have a 1 story rancher approx 1200 sq ft. The oil boiler is a Buderus G115WS/3 the circulator is Grundfos UPS 15 58 FC on high speed. So far one plumber says I need to have basement on a separate zone which I really don't want to have to heat seperate from house originally these house never had heat in basement. Another heating contractor said I need to change tees to monoflow tees but these radiators are at the end of the runs and only one comes off a tee and he would not guarantee this would work. I am so frustrated and its been going on for almost a year and preventing me from finishing up my started finish basement. Any help would be greatly appreciated. I included some pictures.


  • Jamie Hall
    Jamie Hall Member Posts: 21,112
    No fundamental reason why it shouldn't work as piped, except... if you were water, why would you want to bother to go through those two long radiators, rather than all the other radiators?

    The person who talks about monoflo Ts is clueless. Forget him.

    The person who talks about a separate zone -- that would solve the problem, but as you note would be a bit of a nuisance and you would need to do some repiping and add another pump and thermostat.

    So -- a question. When you bleed these two radiators, you do get water from them? If yes, then the solution is to persuade the water to go there -- which means slowing the water down to all the other radiators until you get a satisfactory balance. What sort of valves, if any, are there on the other radiators? It's possible those could be used. If so, and they work (always a question) you could just try to see what happens if you close them down a good bit. Do you then get flow through the basement radiators? Does the pipe from the supply to the radiator even get hot?
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • unclejohn
    unclejohn Member Posts: 1,830
    Can you show a picture of the piping at the rads that don't work.
  • johnnygoat
    johnnygoat Member Posts: 5

    When I bled radiators I get water. There are no valves at radiators. Supply side does get hot about a foot and a half from the top of the ceiling but return does not get hot.as far back as main return line (branch off return main). Included is pictures of piping really nothing fancy just tees and elbows to radiators.
  • johnnygoat
    johnnygoat Member Posts: 5

    EBEBRATT-Ed Member Posts: 13,450

    3 options for a fix.

    A larger pump may work by giving you more flow, not gauaranteed

    Make the basement a separate zone. This is a sure thing

    Add some balancing valves to the upstairs radiators. (unles you have valves as @Jamie Hall mentioned)This is a sure thing.

    Best option is a separate zone. Water is lazy and take the path of least resistance. And it is more difficult to push it down.

    Proof that it is lack of flow is shown by the basement radiator closer to the boiler does work

    Basically you have more places for the flow to go than the amount of flow you have so the water takes the easiest path

    If you put balancing valve on the first two radiators on each loop you would probably be fine

  • johnnygoat
    johnnygoat Member Posts: 5
    What pump would you recommend. What balancing valves would you recommend. This may be a problem on one side because of a finish ceiling may be able to get one on the second radiator and one on the last radiator would this work. If the two radiators where put on a separate zone what would you need to do. Would plumber need to run a new supply and return line or just a supply line. I really did not want to run more piping and heat separately from house. Thanks all for suggestions.
  • duffy_4
    duffy_4 Member Posts: 79
    You could run 1/2” pex alumimum pex supply and return to each bsmt radiator and cap existing feeds. Install two zone valve and manifold at boiler.add isolation valves for boiler pump good idea saves bleeding system down the road.
  • johnnygoat
    johnnygoat Member Posts: 5
    Thanks Duffy now just gotta find someone that knows how to do the work. I just don't understand why I have to do all that work for two radiators. Seems like a lot of work. I did find a set of ball vavles on the first left side of drawing 12 ft. radiator but shutting them down did nothing. Thanks
  • TAG
    TAG Member Posts: 751
    Years ago my brother in MA had a similar situation. Previous owner added cast baseboard when they did a basement remodel -- the rest of the house was upright cast iron radiators. The copper supply and return for the basement was simply cut into the black pipe supply and return near the boiler. System had one pump and the basement never worked very well. We calculated that there was enough running feet of radiator in the basement -- it just was not hot.

    My solution was to cut in and add a small pump/ relay control on the copper supply to the basement loop and add a thermostat on the control. It was set up so the new pump could only operate if the main loop to the rest of the house was running ... but, he now could control the basement loop. Fully running it would have overheated the basement.

    I'm not an expert -- but, it was a simple solution and is only a couple hundred in parts. The new pumps today use even less power vs what we used ... think it was 85w