Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

slantfin boiler

s150dp field control damper does not operate -if you jumper burner fires-but if you disconnect thermostat burner does not shut off any thoughts -with damper hooked up voltage drops to 14 v disconnect harness 24 volts - yellow wire comes off z on aqua stat relay to harness


  • Steamhead
    Steamhead Member Posts: 15,999
    Motor assembly on the damper may be bad. A replacement motor assembly is available. Not sure if you're a pro or not- if not, have a pro handle the job. That damper has to work just right to be safe.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service