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Cold Start Oil?


I have swapped my coil for a indirect. Now i want to convert my boiler to a cold start. I have a triple action aquastat now with a taco sr 503. I was gonna remove the triple action and replace it with a Hi limit aquastat. How do i do that? I was think about jumping H to x1 then Running x2 to the hi limit then to the burner. Sound good? Only concern now is that i will be circulation cold water until it heats up. Any suggestion on wiring or controls? 


  • Tim McElwain
    Tim McElwain Member Posts: 4,506
    What is heating

    the indirect????
  • Jim Hankinson
    Jim Hankinson Member Posts: 99
    Cold start oil

    If you've ever serviced a cold start oil boiler you would see good reason not to use cold start.

    Instead of converting to cold start, turn the low setting down to about 110º. Your boiler will thank you. The small amount of oil consumed is cheap insurance and the boiler will stay cleaner, which in turn helps maintain operating efficiency. Cold boilers sweat. Oil burners do generate some scale that coats the boiler surfaces. Scale plus moisture makes cement that can be a real pain to remove.
  • shoudabeenaplumba
    shoudabeenaplumba Member Posts: 74
    You'd have to change you Auquastat

    The cost of changing you're tripple aqustat probably wouldn't make it worth it. There is, however a trick to elliminate the low limit.  There's a blue wire on the auquastat.  I'm not suggesting you mess with it, but that's what tells your boiler to heat back up.  After all, that's a UL listed device and any alteration will cause sparks to fly out of the flue and burn your house down.

    Another question to ask is how old is the boiler, and is it of steel or cast iron design.  You might be able to get away with it if you've got a steel boiler, but a 10 year + old cast iron sectional will have a good chance to start leaking when it cools down.  I mention this because I've done the exact same thing,  I started with a Trianco steel boiler w/ tankless, then converted to indirect and "changed" the auquastat.  The only leaks were from a flange near the return, but I wouldn't have tried it if it had been a CI sectional. 
  • Tim McElwain
    Tim McElwain Member Posts: 4,506
    edited January 2010
    I read this posting again

    and if all you want to do is eliminate the low limit feature on the Triple aquastat relay then do the following:

    Remove the wire from the "B" terminal on the R-W-B side and jump out "R" and "W". Be sure and make sure the system shuts off on limit after doing this wiring change. You have now made the relay a hi-limit only relay (cold Start). Now the aquastat on the indirect will operate the boiler so it is not really a cold start as you are still maintaining temperature.

    The indirect should now be wired to the priority connection on the Taco 503.
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