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teledyne jvt100c boiler

1955 Member Posts: 1
my gas valve and pump turn on but after 4-10 seconds turn off. I changed the pump relay, did not make a difference.
Zone valves are open, pump runs fine when wired direct. any thoughts welcome


  • Abracadabra
    Abracadabra Member Posts: 1,948
    heat exchanger sooted up? roll-out switch tripping?
  • kcopp
    kcopp Member Posts: 3,819
    What is the gas pressure? before and after start up?
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,837
    edited April 2016
    Make certain there is a good ground between the pilot assembly and the gas valve. That's a Honeywell Smart Valve if I am not mistaken and it is very susceptible to poor ground problems and loss of flame signal. You really need a digital multi meter to see what it is that is causing flame loss. If you don't have that ability, should hire someone who does..

    After re-reading your post, it appears the short cycling may be coming from the thermostat. Check the anticipator setting on the thermostat.

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • G_P
    G_P Member Posts: 7
    FYI, the JVT100C is a standing pilot boiler, most likely from the 1980s. There may not be a rollout switch on a unit this old. If the pump shuts down and the gas valve closes at the same time, try jumping terminal R to terminal W on the outside of the boiler. If the boiler runs normally, the problem is most likely the thermostat, per ME.