pilot light wont stay lit

Mitch_4

a crack inthe H.E. inthe weld aboive the pilot assembly. I have found the pilot to overheat that area, the weld to fail, and when the blower operates, the pilot is blown out at the end of the cycle. youfix, test, all is ok, run 1 cycle, maybe 2, and no pilot again.

It does not affect the burner flame too much, but will snuff the pilot after the burner cycles off.

Also look for implosion of the burners at shutdown, pulling the pilot flame off the pilot buner and dropping out the pilotstat

Marko Sokacich

Carrier Furnace

I have a client with a Carrier downflow furnace. MN: 58GP075-GA-110 SN: 5191A03478. Problems with the standing pilot staying lighted. I have replaced the thermal couple, board and the gas valve to keep the pilot light lit. What else would cause the pilot light not to stay lighted all the time? Or has anyone else had problems with this model Carrier furnace and the standing pilot?

Marko Sokacich

> I have a client with a Carrier downflow furnace.

> MN: 58GP075-GA-110 SN: 5191A03478. Problems with

> the standing pilot staying lighted. I have

> replaced the thermal couple, board and the gas

> valve to keep the pilot light lit. What else

> would cause the pilot light not to stay lighted

> all the time? Or has anyone else had problems

> with this model Carrier furnace and the standing

> pilot?

Marko Sokacich

Mitch: Is the implosion caused by a crack in the H.E. area where the weld is damaged from the standing pilot?

Larry F

Outage

I'm assuming all the basic stuff has been done? Pilot assembly (and orifice) cleaned? Heat exchanger inspected for cracks, holes, restriction? Sort of uncommon is a weak magnet assembly in the valve but you've replaced that. Still not sure how a new board fits into all this.

Larry

lekpeter

outage

FWIW, I once had a similar situation and the pilot supply tube supply nut was loose

lek

A.J.

Pilot burner

Sometimes the pilot burner it's self can get corroded enough to give you a weaker flame. Cover all our bases and put a new pilot burner in if you didn't find a crack yet.

Marko Sokacich

> I'm assuming all the basic stuff has been done?

> Pilot assembly (and orifice) cleaned? Heat

> exchanger inspected for cracks, holes,

> restriction? Sort of uncommon is a weak magnet

> assembly in the valve but you've replaced that.

> Still not sure how a new board fits into all

> this.

>

> Larry



I replaced the board because the ice cube relay contacts were arcing very badly when the contacts closed to energize the gas valve. Older boards you could change out the ice cube relay. Just like changing out the contactor on the condensing unit of an A/C system.

Marko Sokacich

Just wanted to say thanks for all of your sugestions. I got the old Carrier running with a little more cleaning of the pilot orifice. Even though I could see light when I looked into the back of the orifice after cleaning it the first time, that just wasn't good enough. Needed to blow some compressed air through the orifice. Must of had an obstruction just small enough so light could still be seen through the hole, but just large enough to prevent the Thermocouple from getting hot enough to energize the pick coil.
Thanks again for all of your timely responses and suggestions.
Marko

Steve M_2

Vent termination

If you've done all the other stuff, I'd check and make sure the vent cap didn't blow off. The wind may be blowing it out. If that doesn't work, replace that dinosaur with a new 2 stage sealed combustion 90+ furnace. You'd be doing them a favor with future energy cost. I think there may be some new federal tax credits available as well as possible rebates from the local utility company.

Larry F

Glad to hear

Glad to hear things worked out. Nice when folks check back to let everyone know how the job ended. Kind of frustrating when so many folks try to help out then never hear the ending.

Take Care

Larry