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Harman pb105 Temperature question

Post in 'The Boiler Room - Wood Boilers and Furnaces' started by Chris04626, Oct 4, 2013.

  1. Chris04626

    Chris04626 Minister of Fire

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    Ok i have my thermostat set at 62 it is 72 in the house and every so often we can feel heat coming from the baseboards. Just started doing this today, the previous 4 days it never did it and we hardly used any pellets, today though we have gone through atleast 1 bag

    Does something else telling the boiler to produce heat, besides the thermostat? OR why would it be doing this?

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  2. heaterman

    heaterman Minister of Fire

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    What is the water temp in the boiler doing? sounds like the boiler is staying hot for some reason and you are getting some gravity flow through the BB.
  3. PassionForFire&Water

    PassionForFire&Water Minister of Fire

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    Maybe there is an overheat protection that is kicking in and is sending hot water trough the baseboard to cool down the PB105.

    Does this pellet boiler model shuts off and ignites automatically or is it always burning some small amount of pellets?
  4. Chris04626

    Chris04626 Minister of Fire

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    the fire goes out and come back on my itself, The temerature guage on top is at just under 180 and i have the max dial set to 180
  5. heaterman

    heaterman Minister of Fire

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    Does the boiler operate/fire up only on a call for heat from a thermostat or does it simply maintain temp based on its own control?
    I would assume the harmon can be set up either way.

    If its hot all the time, you probably have some " gravity" flow going on that is moving heat around regardless of whether you have a pump running or not.

    If as Marc suggests, there is an overheat circuit piped into the boiler/baseboard that could be the case also. The water temp is getting too high and that circuit is allowing heat to bleed off.
  6. Chris04626

    Chris04626 Minister of Fire

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    Well the thermostat has been set to 62 and it has been firing up even when its 70 degrees in the house, so im not totally sure. I know the first few days it, didnt do it, and used hardly any pellets. But yesterday it started doing it and is using alot more pellets. a bag or 2 since yesterday when the previous days didnt even burn 1 bag

    The Plumemr said he set it up so it will maintain itself whatever that means
  7. heaterman

    heaterman Minister of Fire

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    OK. If the boiler is staying hot, which is what the plumber means when he says "maintain itself", you are probably getting some unwanted flow through the baseboard registers due to temperature difference in the pipes.

    Do you have one circulator with multiple zone valves on the piping in the basement? Or, just a single thermostat that turns on the circulator?
  8. Chris04626

    Chris04626 Minister of Fire

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    I just went down and looked and it was buri\ning but no heat was coming from baseboard, i checked the temperature guage on the boiler and it was just over 140, which that is the minimum temp you can set it as, so i guess the water got below 140 so it turned on, but not sure why it soemtimes causes heat to come from baseboards.

    Or why it didnt do it the first few days
  9. Chris04626

    Chris04626 Minister of Fire

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    I have a singular thermostat upstairs that he says will run the pellet boiler and if the pellets run out or the pellet boiler turns off for some reason the oil boiler will automatically kick on and maintain set temperature.
  10. heaterman

    heaterman Minister of Fire

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    Or why it didnt do it the first few days

    Could be a number of reasons for that. But first if you could, tell me about the zone valves/pump configuration in your basement. That will give me some clues.
    How many thermostats are there in your house?
  11. Chris04626

    Chris04626 Minister of Fire

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    just 1 thermostat
  12. Chris04626

    Chris04626 Minister of Fire

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    I only have heating on my main level of the house, the 2nd story does not have heat ran to it, i will add that eventually though, and the basement is not heated
  13. heaterman

    heaterman Minister of Fire

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    So....One thermostat and one pump on the old boiler?

    A picture would be worth a thousand........ :)
  14. Chris04626

    Chris04626 Minister of Fire

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    its so dark down there i dont think a picture would come out very good, but ill try it
  15. Chris04626

    Chris04626 Minister of Fire

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    Flash worked good

    Attached Files:

  16. Chris04626

    Chris04626 Minister of Fire

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    i have my thermostat set at 60 its 70 in the house and every once in awhile you can feel heat coming from baseboards and of course gets hot in here, and im burning a bag or little more a day.
    The first few days of having it installed it didnt have heat coming through the baseboard at all, and only heated the hot water and a bag lasted a couple days
  17. PassionForFire&Water

    PassionForFire&Water Minister of Fire

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    The first thing you need to figure out is why this pellet boiler is firing up when there is no heat call from your zone(s).
    Is it possible that this pellet boiler is always on, even when there is no heat call? If not, something must trigger it to ignite.
    If it is always on then I still think it's the overheat protection that kicks in. Where is that aquastat on the top of the boiler leading too?
    Always on would be a disaster for pellet consumption.
    Did you install this yourself?
    Check page 21 and 25 in the manual.
    Last edited: Oct 6, 2013
  18. PassionForFire&Water

    PassionForFire&Water Minister of Fire

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    How many feed of baseboard do you have in total in this one zone setup?

    How big is the house in SF?

    This is a fairly potent pellet boiler.
    I don't think you will be able to run this efficiently without sufficient heat demand and or thermal water storage of course.
  19. Chris04626

    Chris04626 Minister of Fire

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    No a plumber and heating guy installed it,

    House is about 2000 square feet, i have 5 sections of baseboard
  20. PassionForFire&Water

    PassionForFire&Water Minister of Fire

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    5 sections as in 5 x 8' = 40 Feet?
  21. Chris04626

    Chris04626 Minister of Fire

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    one section is shorter must be 4 feet

    Ill post some more pictures i took
  22. Chris04626

    Chris04626 Minister of Fire

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  23. PassionForFire&Water

    PassionForFire&Water Minister of Fire

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    Hi Chris,

    I would suggest you get your plumber and heating guy back in.

    In my opinion this pellet boiler is way to big for your situation: i.e. at least 50%
    I don't think it will ever perform very efficiently unless you put a good amount of water storage in
    Just my 2 cents.
  24. Chris04626

    Chris04626 Minister of Fire

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    some of my baseboard runs are atleast 12 feet. The house is 2 story plus basement, There is only heat ran to the first floor, eventually we will have a zone ran into the upstairs., maybe even a portion of the basement that we are working on finishing.

    Our regular oil boiler doesn't heat the house well in the winter time. Both the dealer and the plumber said this boiler would work for us no problem .

    Like i said the first couple days it ran perfect, heated our hot water when we needed it for showers and dishes, and did not push heat into baseboards and used hardly any pellets, ever since then though we have been using a bag or more a day and it sometimes pushes heat to the baseboards.

    I am wondering if it just gets to hot it needs a place to dump the water therefore heats the baseboards? Does it need a bigger expansion tank? Bu tthen again why the big increase in pellets burned?

    It seems the temp guage on the boiler is pretty quick at falling below the 140 minimum which then the boiler has to kick back on.
  25. heaterman

    heaterman Minister of Fire

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    Tough to see what exactly the piping configuration is from the pictures.

    What operates the zone valve? Is it connected to your oil boiler or the pellet boiler?

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