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Short Cycle on start

ChrisNY Member Posts: 3
Really need some help on this one.

I am having this problem. When my oil burner tries to start it goes into a short cycle with the burner firing for only about a second or two. Then about 5 or 6 seconds later the cycle will repeat with the one second try again.

I have narrowed the problem to the Zone Valve end switch opening and re-closing and I can also feel the zone valve at the lever, closing partially as the burner tries to start and opening the end switch. Seem like I am getting a voltage drop at the zone valve large enough that the zone valve begins to close when the burner tries to start and opens the end switch and the cycle just keeps repeating. I have replaced the aquastat control due to a bad relay contact on the burner side. Probably went bad due to the short cycling. Honeywell #L8148A1124

I have a seven zone system with honeywell zone valves running off a 100 va transformer. When I jump T to T on the control the burner runs fine.

I would appreciate any help.

Thank you



  • ChrisNY
    ChrisNY Member Posts: 3
    New Information, still not fixed

    I have some more info to add

    One of the Heating zones is an amtrol 40 gal. boilermate it is the one with the smart control. I have been using it this way for the last 10 years, it is piped as a heating zone using the same cir. pump as the heating zones.

    When I disconnect the aqua-stat wires at the amtrol tank and wind them together the zone valve stays open on a boiler start with no problems.The Problem only happens when going through the boilermate electronic control aquastat.

    Any thoughts would help.

  • icesailor
    icesailor Member Posts: 7,265

    Sounds like you figured it out.
  • billtwocase
    billtwocase Member Posts: 2,385
    Smart control, dumb control

    I replace them with the Reto-fit "Z" control kits. It is the old school aquastat for Boilermates. Too many revisions on the Smart controls, and still not a long lasting part
  • ChrisNY
    ChrisNY Member Posts: 3

    Thanks for the help.

    I have ordered the retrofit kit and i'm sure it will work out.

    This is the type of problem that usually happens when i offer to do a friend a favor.

    You know, whenever we offer to do a friend a favor it usually turns into the most strange and unusual equipment behavior you have ever seen, usually making you look like an amateur instead of the expert. Hate that.

    I'm shocked and glad this one happened at my own home on my equipment, really had me going for a while, glad it wasn't at a friends house.

    Again thanks for the help