It’s best if you can “hold back,” the dryer pipe–one wrench holding the dryer pipe, one on the gas connector. If you don’t have room or don’t have wrenches try it without the hold back.
Anyway, this dryer is very simple–there is a glow bar, a heat sensor, and a gas valve with two solenoid coils. On a call for heat, the glow bar will heat up and get very hot. When it’s hot enough, it triggers the sensor, which switches off the glow bar and lets gas flow through the valve, where it ignites.
However: When I tried the cotton settings (the less dry/more dry ones?), I’d only give it 10-15 minutes at a time before stopping the cycle. Figured it would have heated up by then. Probably attempted this three or four times.
The next day, I tried running a few timed-dry cycles in a row, for a total of about three hours run time. This was in an effort to give the dryer multiple chances at bleeding air out of the gas line before finally getting some gas through the line (similar to how we had to re-start the stove, see above).
I tried one more hour of timed dry yesterday, to no avail.
The same gentleman who replaced our old gas cocks came back to my home just now to make sure the dryer was getting gas. Air is bled out of the line. The gas connector/flexi-pipe was removed and re-installed in the opposite direction. There was a fitting between the dryer and the flexi-pipe that I didn’t know about – he also replaced that fitting.
No clogs. Nothing wrong with the new gas cock or the flexi-pipe. The natural gas is flowing just fine to the dryer.
To no avail – the dryer still doesn’t get hot. On to a visit from an appliance repairman next week. Unless I work up the nerve to disassemble the dryer.
I now know that the deal with the Safety+Plus valve is: It is not an integral part of the gas connector/flexi pipe – it is a separate piece that can be either used or unused as desired.
The family friend who originally replaced the flexi-pipe the weekend before last … he simply neglected to use the Safety+Plus valve. It was still in the package this afternoon. I was not knowledgeable enough about this stuff to even realize what that valve actually was
Most dryers have a couple of thermostats that cycle the heat on and off, and a hi limit, which is a kind of thermal fuse–if it gets too hot it either cuts out the whole dryer cuts out the heat.
It looks like it’s part 500 here.
Gotcha. Yeah, the drum spins just fine. Just that the air inside the drum doesn’t warm up.
Here’s the Cliffs Notes of the series of events.
Dryer works perfectly.
Faint gas smell noted behind dryer.
Home gas line pressure-tested at the meter to confirm inability to hold pressure (aka, “a leak somewhere”).
Gas service to home turned off at the meter.
Gas connector/flexi-pipe behind dryer replaced, as it was assumed to be the culprit. We had dealt with a cracked flexi-pipe once before, and we thought that our poorly balanced “walking” washing machine might have dug into & cracked the dryer’s flexi-pipe. Dryer needed to be slid ~4 feet to gain access to the flexi-pipe, then returned to it’s original position.
Home gas line pressure-tested (with compressed air) a second time at the meter, failed to hold pressure again.
1960s gas cocks feeding the hot water heater and gas dryer replaced with modern hand-turn gas cocks. Dryer needed to be slid again ~4 feet to gain access, then again returned to it’s original position.
Home gas line pressure-tested (with compressed air) a third time at the meter, lines held pressure successfully.
Gas service to home turned on at the meter.
Air bled out of the lines to the gas stove and the water heater. After multiple attempts, both appliances started up and functioned normally.
Gas dryer would not function normally – drum spins normally, but no hot air. Multiple attempts to start device undertaken over three days.
Yesterday, gas-line repairman came out and double-checked gas cock feeding the dryer and the dryer’s flexi-pipe. Dryer yet again needed to be slid ~4 feet to gain access, then again returned to it’s original position. All is well gas-wise – the dryer is, indeed, getting gas.
Gas dryer still does not function normally – drum spins normally, but no hot air.
If something has gone wrong with some mechanical component in the dryer … of course it’s possible, but it’s a heck of a coincidence. Any chance the dryer sliding around messed something up?
Figured out the bolded – what gnarator refers to as the “glow bar” does, indeed, electrically function. It’s akin to a giant automobile cigarette lighter. It heats to an orange glow and (presumably) produces what should be sufficient heat to ignite the gas coming in to the dryer. The glow bar cycles on and off, controlled by one or more solenoids.
Anyway – with the glow bar coming on intermittently, the air in the drum gets a little residual heat. A very little, but noticeable when we’ve let the dryer run for long periods of time as described upthread.
Well, you’ve narrowed it down. It’s getting gas and the ignitor/glow bar is getting hot.
It has to be a sensor or the gas valve.
That requires checking with a meter. A repair guy will use the wiring diagram to confirm voltage is getting to the gas valve.
The valve requires voltage to open. Hopefully it’s something simple like the sensor. The sensor acts like a switch that turns of power to the valve.
The electronic gas valve isn’t difficult to replace. But it’s best left to a service tech or a very experienced homeowner. Replacing the coils may fix the valve. The service tech will know.
From my own experience and from what I’m reading, the drum can still spin in many types of dryers even if the safety fuse/thermostats are bad. And there is probably more than one. Mine had three similar looking fuses/thermostats to check. I think I see at least two in the parts list linked to upthread.
I call them glow bars, but it’s a hot surface ignitor, or just ignitor. Here’s a wiring diagram: GNA31-16200-Mini-Manual-1272.pdf (1.4 MB)
The drum outlet and safety (High Limit) are in line with the valve assembly, so if the ignitor is glowing and getting hot, they’re ok. The control inlet thermostat is in the other power lead, so it’s most likely one of the gas valve coils.
I suppose a wire could be bad or come loose when moving the dryer, but that’s unlikely.
I see a flame sensor in the circuit. It could be dirty. That would cause the burner to light and then go out.
The gas valve can’t stay open unless there’s a burner flame. A dirty flame sensor is a common problem in gas furnaces. I would assume its true in gas dryers.
That’s a very easy fix.
There’s a inspection port (right front corner) that allows you to see the ignitor and flame with a mirror. Turn on the dryer and use a mirror to watch the ignitor glow and see if the burner briefly lights.
It’s shown on that circuit pdf. They explain how to use a mirror to see.
I attempted this while the dryer was off, expecting to see a hole or something. I’ll try it again while the dryer is running.
Meanwhile, an appliance serviceman is coming to the house to have a look this evening. Hoping it’s a dirty flame sensor – I could see a lint bunny resting just so and causing the issue.
