Bryant Gas Valve Problem

[Grovehvac]

Bryant gas package unit
Model 582ANW024060AAAD

Went on a call today for a gas pack. Turned the breaker back on and furnace immediately lit for about 20-30 seconds then dropped out. Checked voltage going to gas valve had 27 volt.

Check out going from gas valve and had 0inwc. Figured ok bad valve.

Replaced the valve, started up the unit and it immediately lit. 20-30 seconds later same as the old valve, not feeding gas, still 27 volts feeding the valve. No codes on the board and all safeties are made.

Check the incoming gas pressure had 8.07 in wc. Could be bad valve out of the box, but I find that unlikely since the old one was doing the same thing. What am I missing? I’ll answer any questions I’m not thinking of if I missed pertinent info.

Joel

[stumpdigger]

r u in the snow belt?

[stumpdigger]

people like to shovel snow onto gas meter/ regulator, next no gas, go figure. Does their gas range run on all four burners?

[stumpdigger]

Did you, like, check incoming gas pressure?

[Grovehvac]

Not in the snow belt. Water heater will light and operate normally. Incoming gas pressure was 8.07inwc.

[rundawg]

Bryant gas package unit
Model 582ANW024060AAAD

Checked voltage going to gas valve had 27 volt.

What am I missing? I’ll answer any questions I’m not thinking of if I missed pertinent info.

Were you measuring the 27v to the gas valve with its gray and brown wires connected to the valve, or removed from the valve?

When I have situations like this, I connect the gas valve wiring to a separate contactor to see if it will engage when the control board sends 27v to the valve.

If the contactor doesn’t engage, you have a high resistance connection somewhere in the circuit. You can measure the 24 volts on the gas valve leads because the meter does not place its own load on the leads, but not have enough current to pull in the contactors armature, or open the gas valve.

[TechmanTerry]

8.07" WC? Thats not good,of no! Thats low press if its LP or too high if its Nat,I think. Manifold press.

[Grovehvac]

That was measured at the gas valve leads. I’ll try the contactor trick today and see what it does. I was wondering if 8.07 was to high. Wasn’t sure if that would be high enough to put to much pressure on the valve.

[TechmanTerry]

That was measured at the gas valve leads. I’ll try the contactor trick today and see what it does. I was wondering if 8.07 was to high. Wasn’t sure if that would be high enough to put to much pressure on the valve.

What fuel?

[rundawg]

I was wondering if 8.07 was to high. Wasn’t sure if that would be high enough to put to much pressure on the valve.

The manual states the inlet pressure should be in the 4.0" - 13.0" wc range for both natural gas and propane.

Is this a natural gas unit?

[slctech]

If it is a natural gas, 8"wc is just fine.

Another thing I would add, were you checking the inlet gas pressure the entire time the gas valve initiated burn and until the burners went out? If It stayed fairly stable after the initial small drop in pressure that comes after ignition, then you can rule out the gas side of the issue. Sometimes if you have a failing main regulator or, as stated, an ice dammed or snow locked regulator you may have enough accumulated gas load initially to allow light off and even some burn time, but then the regulator can not maintain the flow and soon the gas pressure diminishes and you lose flame.

[rundawg]

If it is a natural gas, 8"wc is just fine.

The system he has is one of those odd units that was designed to have the same manifold pressure for natural gas and propane - 3.5” wc.

[slctech]

I should clarify in my post that IF it is natural gas, 8"wc of INLET pressure is just fine.

[Grovehvac]

Unit is natural gas. I unfortunately wasn’t checking incoming when the unit did light for that short time. One thing I found odd was that the board never did lock out. It would try to light repeatedly with no codes. But it was acting normal as far as sequence which kind of lead me to think the board is ok. I’m wondering about the resistance you mentioned earlier. I’ll check that when I go back over there today.

[slctech]

Unit is natural gas. I unfortunately wasn’t checking incoming when the unit did light for that short time. One thing I found odd was that the board never did lock out. It would try to light repeatedly with no codes. But it was acting normal as far as sequence which kind of lead me to think the board is ok. I’m wondering about the resistance you mentioned earlier. I’ll check that when I go back over there today.

So I guess the game plan then when you return is to first monitor the inlet gas pressure as the unit fires off initially and see what that pressure does, if it starts to diminish to the point you lose the burners, you know it is not the unit itself, but a gas supply problem. If the gas pressure stays fairly constant and the burners just shut off, then bring out a regular old contactor and see if the board can pull that closed, then you know it is not the board and also may not be the gas valve. Keep in mind that it may be another component that is causing a voltage drop, could be the blower relay? Maybe after the burners light and after the blower delay and that blower relay/contactor is energized, maybe that component has an issue?? Maybe not, not sure if the blower is controlled by a board relay, contactor, etc. Just stuff we all here have experienced in out careers, doesn't mean it is the same for every unit. But having the burner drop out about 30 to 40 seconds after initial ignition may coincide with the blower being turned on, a thought.

[stumpdigger]

So I guess the game plan then when you return is to first monitor the inlet gas pressure as the unit fires off initially and see what that pressure does, if it starts to diminish to the point you lose the burners, you know it is not the unit itself, but a gas supply problem. If the gas pressure stays fairly constant and the burners just shut off, then bring out a regular old contactor and see if the board can pull that closed, then you know it is not the board and also may not be the gas valve. Keep in mind that it may be another component that is causing a voltage drop, could be the blower relay? Maybe after the burners light and after the blower delay and that blower relay/contactor is energized, maybe that component has an issue?? Maybe not, not sure if the blower is controlled by a board relay, contactor, etc. Just stuff we all here have experienced in out careers, doesn't mean it is the same for every unit. But having the burner drop out about 30 to 40 seconds after initial ignition may coincide with the blower being turned on, a thought.

Love the way you think! Chase the gas then chase the voltage drop. Nothing like inrush currant to screw with systems.

[Averagetech37]

Just a thought is this 2stage? I had one throw me for a few minutes would light run for 10 minutes then drop on flame sense. Tracked it down to relay on circuit board for second stage was bad. First stage would run just fine.

[mike3]

Might check the appliance valve for partially closed or a wad of grease blocking flow

[beenthere]

So what did you find.

[slctech]

So what did you find.

It's not often they return to report.