My gas furnace will run one cycle and then not come back on until the switch is reset. Once the switch is reset it will kick on immediately run once and again I will have to reset before it will kick on again. It only does this when the temp outside drop below 30. When it is above 30 degrees outside it runs perfectly fine. Its always usually set at anywhere from 65 to 72 degrees but it could be 45 degrees in the house and still will not come back on until reset.

Things you should know:

  1. This is the first year this furnace has been used in approximately 18 years.
  2. It had apparently been red tagged due to needing a new thermostat.
  3. I just had the thermostat replaced about a month ago.
  • 1
    Was this issue solved? If the furnace mid or high efficiency? Model number? Do not know anywhere in the gas code where a fuel burning appliance can be red tagged for a thermostat? – JASON FOREST Apr 18 '15 at 2:15
  • The safety chain is doing what it's supposed to. Your problem is whatever is causing the unit to go into "lock out". – Mazura Jun 18 '16 at 1:10
  • What kind of reset do you mean? Is "reset" something you do at the circuit breaker panel, at the furnace, or at the thermostat? – wallyk Jul 18 '16 at 2:31
  • 1
    Voting to close as unclear. Several unanswered questions remain, and OP hasn't been back. – isherwood Nov 21 '16 at 17:43
  • Honestly the core problem is the 18-year downtime. If you want stuff that'll just reliably work after 18 years, talk to NASA but even they have problems with it. Having a "vent" to the outside only makes things worse, because it allows moisture to enter, causing rust/oxidation, as well as dust, bird nests, vermin etc. Considering the nasty downside of a failure (house fills with gas), I would not run the unit without a very careful going-through and precautionary replacement of marginal or critical parts. – Harper - Reinstate Monica Nov 29 '16 at 21:35

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