Furnace flame out

[weldon]

I had a call on a gaspak at a lake house. The unit faces the lake. After a night of 35 mph sustained winds and high gusts the unit had a flame out. The unit is spark ignited with a combustion fan. Upon arrival combustion fan was running but burners were not. I checked all controls and everything appeared to be in working order. Turn the thermastat fan to on and fan worked. Turn thermastat off and back on and unit fired and ran fine. Is it possible for high winds to extinguish the burners and not allow them to light the second time causing unit to go into lock out?

 

[DRWeig]

Hi Weldon,

Yes, it's possible for high winds to snuff the flame out, and I would think that flame failure would cause a manual-reset condition if the controls are designed properly. You'll have to look into the manufacturer's control sequence to find out for certain though.

Larger boilers work that way. The lock-out is to prevent operation until somebody can visually determine that the igniter works OK.

Let us know what you determine!

Old Dave

 

[KenRad]

One of the safety devices found on gaspacks is a flame rollout switch. The device is usually mounted outside of the burner opening, and is designed to shut the gas valve in the event that the flame rolls out of the burner. This can happen if the vent is blocked, if the heat exchanger has developed a hole (and indoor air flow is pushing air toward the burner) or if high winds disturb the vent flow.

It could have been this switch, or it could have been as DRWeig said, and the flame blew out. Once the flame sensor stopped seeing a flame, it would have shut the gas valve. Either way, it sounds like you fixed it.

---KenRad

 

[Rodale]

There is a pressure switch in the induced draft assembly (IDF). During a high wind condition the IDF may not be strong enough to operate the switch. This results in a safety lockout. Most current controls are reset by turning the power off and then back on.