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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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    my oil boiler has no idea there is a pellet boiler in the mix...I tied into the return lines so all it knows is the return water is hotter..::P

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  2. Fred61

    Fred61 Minister of Fire

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    Then just add an aquastat like an a419 and break that circuit. You'll also need a relay to handle the load.
    iceguy4 likes this.
  3. ozzie88

    ozzie88 Member

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  4. ozzie88

    ozzie88 Member

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  5. iceguy4

    iceguy4 Minister of Fire

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    Hey ozzy
    I have a vent damper and have for 4 years know. please don't take this wrong cuz I appreciate ANY help ...IMHO FIELD CONTROLS oil vent damper http://www.fieldcontrols.com/ovd.php Is a better choice. Let me splane...If you look at the picture you can clearly see the stainless "feathers" on its edges. these work two ways...first they seal the vent quite nicely...thus eliminating leakage. More importantly they clean as well as will go over any crap on the pipe walls left there by oil combustion, and believe me there WILL be crap. Also my unit is ALL stainless. Are you aware oil vent dampers (reliable) were not available for an oil application? Again please dont take this wrong and if you notice I "liked" your post
    Iceguy AKA Tony 20 Sharks
  6. iceguy4

    iceguy4 Minister of Fire

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    fred,

    where would you have me install that aquastat? every place on my system will become hot when the oil boiler kicks on...
  7. ozzie88

    ozzie88 Member

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    Info-info cant get enough info,, somethings you have to keep talking about till somebody hits it on the head and fix the problem, This is a good site with lots of people and ideas. Good luck I will keep checking this I too am baffled with your problem, People here have helped me in the past,
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  8. KenLockett

    KenLockett Member

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    Ice,

    Yes I live near Albany. I live east of Troy in the town of Petersburgh. If you'd like to come out please just private message me and we can setup a visit. Attached is a picture of the schematic. I can email you the schematic in .pdf format if you private message me.

    Ken

    Attached Files:

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  9. Fred61

    Fred61 Minister of Fire

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    You'll need to set your oil boiler launch temp lower than the PB and then use a locking relay that will activate when PB temperature drops below that point and then you would manually release oil boiler when you refire the PB.
    iceguy4 likes this.
  10. Since its plumbed in series an aquastat wouldn't work. I'd just put a new simple thermostat in the main living area and set it to 5-6 degrees lower than the the temp you keep the house. Run a pair of thermostat wires from the thermostat to the tt connections on the oil burner primary control.(it should have a jumper that you will need to remove)

    That way when the pellet boiler is providing heat the new thermostat will be satisfied and tt connection will be open preventing the oil burner from firing. If the house cools to the setpoint the thermostat will close the connection and allow the oil burner to fire.
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  11. TheMightyMoe

    TheMightyMoe Minister of Fire

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    Due to your plumbing being serial either run a wireless back up thermostat just for the oil boiler.

    Or add a delay start relay to boiler.

    Edited my post for clarity

    http://www.grainger.com/Grainger/SSAC-Multi-Function-Timer-5JJ47?Pid=search

    Wire this between oil boiler / controller / zone valve / thermostat ((Not sure of your setup))

    Set it for a set amount minutes. If pellet boiler does not meet demand of thermostats in set time, oil boiler will kick on, until all demands for heat are satisfied.

    *Example*
    Timer set for 30 minutes

    Oil boiler will not run, unless the call for heat hasn't ended after 30 minutes, then the oil boiler will run till call for heat ended.

    You may run into problems with multiple zones, but you could set the relay to 60 or 90 minutes. Really depends on how long your call heats are / # of zones / how much time your willing to go without heat.

    Seems like the cheapest option to me, if its doable.
    iceguy4 likes this.
  12. iceguy4

    iceguy4 Minister of Fire

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    Thanks guys. what do you think of this Idea...change out my aquastat to a more adjustable one with an ajustment on the lower limit of say 110 degrees. I have allready staggered my setbacks so they dont all hit at the same time. keep my high limit at 180. I have seen temps drop into the 115 range and I have the pellet boiler set at 170 LL and 185 HL ...BUT i just finished the outside temp so these values will change. A side note...for the first time in 2 years I have gone back to indirect water heater as even during the heating season I'll bet my 40 gallon electric HW heater was cheaper then oil. Man I just got out of the shower (3 valves ...one for regular head spray with wand too, one for body sprays and one for rain maker...all at different temps_g:rolleyes:) A true "tim the tool man" shower LOL
  13. TCaldwell

    TCaldwell Minister of Fire

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    Ice, have you followed all the thermostat wires, I had one that a electrician wired to the oil boiler switch, so whenever that zone called the oil bolier would kick on, regardless of water temp in my series piped wood boiler. Once I hooked that thermostat to the taco zone conntrol box, no more oil boiler.
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  14. TheMightyMoe

    TheMightyMoe Minister of Fire

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    Your pellet low limit seems high.

    Also how long are your returns staying at 115*? I know the the PB wants 140* return water if possible, and it sounds like your home takes a while to heat up after you setback.
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  15. iceguy4

    iceguy4 Minister of Fire

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    I'm not understandind this...please explain better or pm me and ill call you. I was just down stairs (my wife said i might as well stay there...LOL) this is what I got a 6 zone Taco sr506 controller to handle the zone valves. from the XX termonals on that its wired to the TT termonals on my aquastat to tell the aquastat that there is a call for heat from one of the 6 zones. I disconnected one of the TT wires from the controller and wa -la... no oil boiler . this solves the problem of where I had the boiler disconnected (at the oil burner) this stopped the burner from fireing but my vent damper was open. I could just wire another thermostat to the TT termonals in my basement as a fail safe to prevent my pipes from freezing BUT this is not a seemless integration install. I'm thinking when I add the other building I will need the oil to help my pellet boiler on the coldest days (inlaw apartment and moms not gonna put up with a cold house). I think it all boils down to me needing a new aquastat that is more adjustable then the POS I have. No matter what I do it will not let me adjust the lower limit. Also that delay relay looks good too. Any ideas of what aquastat would hve the adjustability I'm looking for? would like it to be honeywell if possable Lower limit adjust from a lil over 100 to say 160 and high limit from 140 to 180 give or take. thoughts??
  16. iceguy4

    iceguy4 Minister of Fire

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    Not very long. I have cast iron radiators and have used deep setbacks (50 degrees when I was strictly on oil) I have changed all setbacks to 60 degrees and spent some time synchronizing the clocks in them and staggering the times so they all dont come online at once. Sounds easy but it was time consuming
  17. TheMightyMoe

    TheMightyMoe Minister of Fire

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    Thats good. Too bad you are not plumbed P&S or with Thermostatic bypass valve, then you run all the setbacks at the same time, and get a nice clean long cycle. Although having staggered setbacks can accomplish the near the same thing.
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  18. iceguy4

    iceguy4 Minister of Fire

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    WHOA... slow down:confused: ...plumbed P&S??? thermostatic bypass???
  19. TheMightyMoe

    TheMightyMoe Minister of Fire

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    Primary/Secondary = Way to plumb everything instead of serial (It can be done serial) which gives the boiler protection from low return temperatures.

    Thermostatic bypass = Another form of boiler protection - Not as good as P&S.
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  20. Fred61

    Fred61 Minister of Fire

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    Hey Ice,
    I did some scratching on a napkin and thought about the following. Tell me where I'm going wrong.
    I don't exactly know how you have your system plumbed. but I assume the supply from the PB goes to the return of the OB then OB supplies the zones and return is to the PB.
    Try this on: How about mounting an aquastat on the PB output and a 3 way on the return to the PB that will short circuit the PB when OB is powered up. Three way will divert the return water to PB supply so no flow will go through the PB until the new aquastat is satisfied (PB water temp back into set range).

    ie. PB cools > aquastat powers OB and switches three way > three way diverts water to output of PB. Alt. PB warms > aquastat activates > opens power to OB and activates three way to allow flow through PB. You'll probably need a swing check downstream from the aquastat and upstream from the bypass connection.
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  21. iceguy4

    iceguy4 Minister of Fire

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    Fred,
    How I plumbed it in... 1 foot before my old return went into the bottom of my boiler, I "T'd" in with my hot line from my PB105. directly above I placed a ball valve then above that I installed another "T" for the return for the PB105....so its a "series" set up . IE my hot water from my pellet boiler must go through my oil boiler befor going to the zones.
    I dont understand completely... seems like a complex arrangement and my system is going to have to be plumbed like it is till spring at this point. thank you so much for thinking about my situation:) read below what I'm going to try tonite.
  22. iceguy4

    iceguy4 Minister of Fire

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    since I dont have the money for another aquastat at the moment I just lowered the "heat low limit" on the intellidyne hw+(wonderfull device that I installed 3 years ago on my oil boiler) to 91 degrees. if the temp drops slowly it will hold off oil boiler from firing to that temp. if the temp drops too fast it will let the boiler fire at a much higher temp. I think if I install a delay relay I will get the results I'm looking for. It was set at 120 degrees before but I never saw it go below 128 degrees. It breaks my heart when I hear the oil kick in...<>
  23. Fred61

    Fred61 Minister of Fire

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    My quick napkin design would add a Johnson Controls a419 plus a three way valve plus a tee and swing check valve. About $250.00. Simple design. not complicated at all.
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  24. steam man

    steam man Minister of Fire

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    I am just putting a wood boiler this month with storage. I am leaning towards just using a flow switch. If the wood boiler is citrculating hot water it will inhibit the oil burner. My problem with strap on aquastats is the delay in switching due to just sensing pipe temp and not any actual flow.
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  25. iceguy4

    iceguy4 Minister of Fire

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    steam
    flow switch will not work in a "series" plumbed system as there is flow through each boiler no mater what boiler is firing. am I missing something here?:( My problem is ...I'm "tighter then bark on a tree" so adding yet another circulator to a system with 6 curculators makes my teeth hurt...and besides heating my oil boiler costs me next to nothing as I have a flue damper and any heat lost there is still in my building.

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