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How to stop oil boiler from firing unless needed

Post in 'The Boiler Room - Wood Boilers and Furnaces' started by iceguy4, Dec 1, 2012.

  1. iceguy4

    iceguy4 Minister of Fire

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    Pb 105 installed...up and running :) Changed all my set back thermostats (up from 50 degrees) and now my wife is very happy(house @ 70+ degrees) My oil still come on at times but in 24 hours it has only run 30 min (hour meter). would like to nip that in the butt. My boiler is plumbed in series and no one here seems to know how to stop my oil burner from comming on . I only want my oil to come on in an emergency. Can anyone help?

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  2. kopeck

    kopeck Minister of Fire

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    Is your oil boiler a cold start?

    With my setup, which is quite different then yours, I just use a JC A419 to monitor my storage temp. If it fall below a set point then the oil boiler kicks on for heat calls.

    You don't have anything like that and I'm not sure what you could use to trigger your oil boiler in an emergency. I might talk who ever you purchased the boiler from. Makes me wonder if the boiler has some provision for this built in?

    K
    iceguy4 likes this.
  3. harttj

    harttj Member

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    I installed a strap on aqua stat. Temp in the boiler falls below 140 and propane kicks in.
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  4. Gasifier

    Gasifier Minister of Fire

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    My storage tank has an aquastat on it that triggers the oil boiler when the tank goes below say 140 or whatever I have it set at. Could you put an aquastat on your PB to do the same? I do not know how to do it. I hired my installation done. How do you like the PB so far?
    iceguy4 likes this.
  5. ozzie88

    ozzie88 Member

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    Most oil boilers come on when there temp. goes down to certian temp. An oil boiler just sitting there looses heat by the air flow going threw them all the time which will cool them off alot. by alowing air to go threw the pump inlet and out the flue,which cools boiler, I PUT A FLUE ELE. control flap which comes on and off with the pump, on my boiler and it keeps all heat in boiler, stops the air flow cooling it, and I must say it cut down the usage ALOT,
    iceguy4 likes this.
  6. stephenmoore

    stephenmoore Member

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    I Have a PB 105 and use an electric boiler as back up, if both units are piped into the primary loop of your system, you should be able to add a second thermostat to the main zone of your house, if your pellet boiler runs out, the oil fired furnace should kick in after the temp drops.It works great for me.
    iceguy4 likes this.
  7. ozzie88

    ozzie88 Member

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  8. iceguy4

    iceguy4 Minister of Fire

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    yes cold start ...the people who sold it to me could only answer how much $$ they wanted...
  9. iceguy4

    iceguy4 Minister of Fire

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    My boiler (OIL) has a FIELD CONTROL oil vent damper... what is a ELE?
  10. kopeck

    kopeck Minister of Fire

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    Hmm, then it should only fire when there is a call for heat.

    If you truly wanted to only use your oil boiler as backup (ie freeze protection) use something some sort of thermostatic switch (again, similar to an A419) and put that inline on the wire that fires the boiler and set it to 50 degrees or something like that.

    If the air gets below 50 then it would allow your oil boiler to fire. Your thermostats and the boiler would be out of sync BUT it would keep your house from freezing.

    I don't know if that's a great idea but it's an idea...

    Maybe there's something you could tie a relay into on your pellet boiler?

    Still seems (to me) like there would be something on the boiler but I've never played with one so I can't say for sure.

    K
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  11. iceguy4

    iceguy4 Minister of Fire

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    Strap?
    my existing aquastat will try to fire boiler @ 160 degrees. I have cast iron radiators and use a set back thermostat. sometimes my return water is quite cold so my oil boiler kicks on(honeywell L7224/L7248) will not let me lower my low limit 160 degrees or lower my high limit 180. If I could lower to 140 (Low Limit) I think it would help. should I install a new one?
  12. ozzie88

    ozzie88 Member

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    this electric works off controls and comes on and off with pump.opens and closes flue, It sits right on top of stove on ring to keep all heat in when not in use, most are cast iron one i got is stainless,it saves alot of heat. Most high efficentrys have them on already with unit and burn outside air anyways.
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  13. iceguy4

    iceguy4 Minister of Fire

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    my field control vent damper is also stainless. it has "feathers" (Stainless)where it comes in contact with the vent pipe. I presume it is to survive the harsh enviroment that an oil burner presents.
  14. iceguy4

    iceguy4 Minister of Fire

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  15. iceguy4

    iceguy4 Minister of Fire

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    ...
    Also I'm up to 2.25 tons in basement...oink
  16. iceguy4

    iceguy4 Minister of Fire

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  17. iceguy4

    iceguy4 Minister of Fire

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    Yes it will only come on if ther is a call for heat. since i have cast iron radiators my temp can go to 125 + - and they still will warm house ..unlike base board. It just seems like a waste to fire my boiler (oil) when the pellet will catch up on its own. As you know the PB 105 can take a few min to get its self "ripping" and any residual heat in it will start heating the zone that is calling for heat. GEEZ this is getting frustrating looking for an answer:confused:. I'm sure someone has solved this. I was thinking maybe a snap switch on the pellet boilers vent pipe but that seems like a "cob job"
  18. KenLockett

    KenLockett Member

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    Iceguy4,

    My Tarm Solo Plus 40 Down Draft gassifier is not plumbed in series with my oil boiler as I chose to plumb it in parallel as not to have to heat the capacity of the oil boiler reservoir. However, I have an aquastat that monitors the wood boiler temp. The NC contact from the aquatstat is wired in series with the oil burner ignition circuit to provide an interlock. The contact opens when wood boiler temp goes above 160 DegF with approximately a 10 DegF deadband thus preventing the oil boiler from firing. If I let the wood boiler combust out the oil boiler will fire to take up the slack. All in all almost seamless operation between the wood and oil boilers. Remember that the relay and thermostat circuits for the oil boiler system had not changed. The only addition to the original control circuit was the addition of the interlock contact. My only complaint is that I wish I had bought an aquastat that had an adjustable deadband. I have an electrical schematic that I can send if you'd like via private message. Let me know if this helps and/or if you'd like a copy of the schematic.

    Ken
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  19. Fred61

    Fred61 Minister of Fire

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    Having a cold start fossil boiler is an advantage in this situation. Yor don't need to switch the power side of the boiler at all. You just need to switch the thermostat. The boiler will not operate unless the contacts in the aquastat are made.
    I am using a JC 419 that is sensing my storage temperature and have it set to activate when the tank temperature drops to a certain temperature, say 120 degrees. When that happens, it activates two zone valves which re-direct the flow and makes the thermostat connection. As soon as the thermostat connection is made the oil boiler fires. In other words, just switch one leg of the thermostat wire and you're good to go. Fossil boiler will not fire unless thermostat is calling.
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  20. iceguy4

    iceguy4 Minister of Fire

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  21. maple1

    maple1 Minister of Fire

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    A 'strap on' aquastat is one that does not need to be installed in a well. You mount the aquastat where convenient, and 'strap on' (surface mount) the sensor to where it will sense the heat effectively (like a supply pipe, or the top of a storage tank). Very easy install compared to a well aquastat especially when retrofitting.

    Are you sure you can't lower the lower limit of your aquastat?

    You could add on a strap on aquastat in your oil boiler firing circuit - when the sensor senses a temp somewhere in your system that is less than what the PB would maintain if it was firing, the stat would close and let the electricity through to fire the oil burner. That would be a simple 'break on rise' aquastat - they are not that expensive. Or, as mentioned, you could try the room air temp approach & use a separate thermostat to fire the oil if the air temp gets too low - but, how is your DHW heated?
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  22. iceguy4

    iceguy4 Minister of Fire

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    fred,
    My oil boiler aquastat is a honeywell L7224/L7248 and only the High limit is adjustable 180 and up...lower limit is set @ 160 and I havent been able to adjust (its aprox 4 years old) If I could lower it to say 130 or so it would fix my problem. also I have SR 506 Taco controller wired to 6 seprate setback stats so are you saying I need 6 more stats? Also my oil boiler makes so much noise that its nice not to hear it (Its much less noisy with a .75 nozzle...that SOB would fire after a pre-purge with a boom..woosh with a .85..:eek:) I also have an intellidyne HW+ on it for the last few years (I like it and feels it saves me $$ by holding off burner to as low as 128 degrees that I have observed...but thats another thread. I have also moved its sensor to the outlet of the pellet boiler as to sence its heat sooner)
    Now next year this issue will most likely become "moot point" as this system will have to heat yet another building as well as this building and I expect I will need the oil boiler to keep both warm on the coldest days....but I'm like a "dog with a bone" ::-) and will NOT stop till I find a way to accomplish keeping my oil from firing unless my pellet boiler is out. I have cast iron radiators (sand blasted and powder coated...man they are pretty:rolleyes:) so lower temp water to them is less significant then base board so my pellet starting up from a no fire condition will have less of an affect then usual.
  23. iceguy4

    iceguy4 Minister of Fire

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    first off let me thank you for taking time.... Any place in my system I place such a device will kill my oil boiler since my boiler will heat my pellet boiler too as its series...I have no storage as of yet.. What woul I do...place such a device in the line between my Taco sr506 and aquastat in the TT circut by breaking one of those lines? I'm concidering mounting such a device on the pellet boilers chimney... Also I have an indirect HW heater on zone 6 as it can be set up as priority (i dont have it set to on) right now I have the oil burner unplugged but as the temp drops outside I will become less confortable with that arrangement...and besides it skews my intellidyne HW+ run time values that I use for oil consumtion figures(67 hours so far this season and that was with an electric hot water heater that I use in the summer... 67h X .89 gal/hr(flow rate @ 140 psi = gallons used) )
  24. Fred61

    Fred61 Minister of Fire

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    No you don't need any more stats. When I made my statement I had overlooked the fact that you are using them so what I said wouldn't work for you but now I'm confused. If your oil boiler is unplugged, where is the power coming from to power your controller?
    iceguy4 likes this.
  25. iceguy4

    iceguy4 Minister of Fire

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    my burner has a plug at the burner so you can service it...IE swing the front open to clean (utica tri-fire oil boiler)












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