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House is not heating up fast enough

GTH Member Posts: 2
I just moved into a house with radiant floor heating and found the house is not heating up fast enough. When the thermostat,is calling for heat, the pump comes on and then the boiler fires up. The temperature on the boiler goes from f 130 to f 200 in about 7 minutes and then it shuts down. Before the boiler shuts down, the pump turns off (Is this right? How does the pump make the hot water go to the loop when it's off?) So the boiler and pump stays off for 20 mins before the pump starts going and sending the cold water back to the boiler and then the boiler fires up and runs for another 7 mins until it reaches f 200. So the cycles go on like this. It seems like the there is only 2 cycles in an hour. Could this be the reason why the house is not heating up fast enough? The thermostat constantly calling for heat from 7 AM to 6 PM but the room temperature goes from only f 64 to f 69!!!!!!


  • Tom_133
    Tom_133 Member Posts: 767
    There are lots of variables, what kind of radiant? is it in slab, or staple up? Can you post a few pics of the boiler piping from a few feet back so we can see whats going on?
    Montpelier Vt
  • DZoro
    DZoro Member Posts: 1,048
    Radiant flooring is like a turtle, it's going to take its time to get there, when it does its going to want to stay there :)
  • neilc
    neilc Member Posts: 1,455
    ok, so no setbacks,
    but OP still has a circulator turning off and not sending boiler heat to floors.
    we need to see the boiler picture,
    and the thermostat also, it may be set wrong also as far as cycles per hour, or run time, or ??
  • Zman
    Zman Member Posts: 6,965
    You will need to post more details about your system in order to get the answer you are looking for. There are infinite ways to pipe boiler, pictures would help us determine what you are working with.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • Gordy
    Gordy Member Posts: 9,514
    edited February 2019
    I didn’t see where the OP indicated they were intentionally setting back. Seems like they are losing temperature? If you are setting back as others have stated it's not going to work for a system design that's just able to compensate for the load.

    At any rate, the boiler shouldn't be cycling as described.

    At the start of a heat call The circulator should start, then the boiler fire.

    During the heating cycle the circulator should always be running, and the boiler firing until if , and when it reaches its high limit. Which it appears to be 200 degrees.

    At high limit the boiler will quit firing, but the circulator should still be running if the room set point is not reached. When the boiler cools to the low limit it will fire again. This should be the way things work until the room set point is reached. Once room set point is reached the boiler will quit, but the circulator may run a little more then stop.

    A 200 degree high limit is to high especially for radiant. Unless it's a staple up with no plates, and someone turned up the high limit because they could not make the rooms desired set point. Hopefully there is a mixing valve supplying the radiant.

    As others have stated. Some photos, and a better description of the whole system.

    Boiler, and its piping etc.
  • GTH
    GTH Member Posts: 2
    Thank you all for the comment. Pardon me if I ask dumb questions since I just started learning about the whole system. So after the boiler shuts off, the pump should should still be running if the room set point is not reached. My pump sometimes even stops running like 1 minute before the boiler's temperature reaches the high limit and shuts off. Here is something I noticed yesterday: The boiler goes up to f 200, shuts off, the pump shuts off. 5 minutes later, I guess its the switch relay that makes a click sound and the pump goes on and the water starts returning for like only 2 seconds and click the pump goes off. 3 minutes later, the same thing happens again. Another 3 minutes passes, I hear a click again only this time, the clicking sound lasts like 1 minute (the sound is not like click, click. click..... more like a continuing humming sound) but doesn't turn on the pump. A few minutes later, the same thing happens again. Then finally, the boiler temp reaches the low point, and click the pump goes on starting pumping the water to come back.

    My question is: Could the pump or the switch relay be the culprit ? What controls the pump to go on and off?

    Here are some pictures of the system.
    JUGHNE Member Posts: 8,927
    How can you tell the pump stops? Is it that loud when running?
    Usually you can not hear the pump running unless the room is very quiet.
  • icy78
    icy78 Member Posts: 397
    You have end switches on those zone valves, starting the pump? Bad switch contacts. Or pump cycling on internal overload, or anticipator set at 0.1, on old mercury stat? Or relay maybe.
    EBEBRATT-Ed Member Posts: 10,235
    You have 2 pumps. 1 on the left side of the boiler and 1 on the back wall. Which one is running, if any? Which one is going on and off?

    Nee more pictures of the piping on the left side of the boiler and behind the boiler.

    It's some type of primary secondary system I think. We need to find out what controls the water temperature to the radiant zones. The boiler may run up to 200 but the radiant zones are usually 120 deg supply or so depending on the installation. Must have a 3 way valve somewhere????
  • Zman
    Zman Member Posts: 6,965
    I suspect that the zone valve end switches are not holding closed. You might start by adding a zone controller like the taco ZV series or Calleffi..
    If you want to test this, jumper the TT terminals on the boiler and see if it operates correctly.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • SuperTech
    SuperTech Member Posts: 1,687
    I can't tell exactly what is going there, I need to know what that blue pump is for, and that wiring needs to be checked out.
  • Lance
    Lance Member Posts: 170
    Divide and conquer. Leave the burner off. Keep it from running. Set the pipe aqua stat way up. Set your thermostat 4F higher than room temp. Verify if the circulator stays on, if it does not, or cycles it or its wiring circuit may be the problem. Check the heat anticipator adjustment if your stat has one; should be at 1.0Amp- 1.2amp. If digital with switches for system type, make sure it is set right. Multiple zones add load. The transformer needs to big enough. 20 watt for boiler, another 20-40watt for zone valves.
    Circulators should run until T-stat is satisfied. regardless of burner operation on a call for heat. Exception would be a summer winter priority override for domestic hot water. Adjust aqua stat. This is a designers choice to add to system. Is it to shut off or turn on a thing, a pump? Is it working as intended; placed in proper position for its function?
    The last thing to do is usually the first to do, read the manufacture's specifications. A boiler is just a pot on the stove. A heat system is many components based on a design to function a need. I have to know how its supposed to work to actually make it work. I maintain a sequence of operation list in my head and on my jobs.
    EBEBRATT-Ed Member Posts: 10,235
    @GTH, I would NOT turn up the aqustat until you know what controls the radiant temperature.

    If you put 200 degree water into the radiant you will have big problems
  • Gordy
    Gordy Member Posts: 9,514
    ^ that’s my concern. Especially why it’s set to 200 to begin with in a radiant application. Plus we don’t know much about the radiant design. Sounds like a suspended tube with the aquastat setting.........
  • Bill_17
    Bill_17 Member Posts: 68
    It is hard to follow all the pipes, but is the Taco pump moving water toward the mixing valve or away from it?