[rje45]

I bought a used gas dryer from some fly-by-night retailer and I've been having problems ever since.
The problem is that it will not heat up after completing a few cycles. I've replaced the coils and the igniter. It may run through an entire load, and it may only run through one burner cycle. Some times, the igniter doesn't kick on at all. The valve relay is closing when it is supposed to.
I took the burner assembly to a local shop twice to have it bench tested and they're telling me its running fine. This was with my flame sensor.
The thermistor is measuring 13k ohms. All of the thermal fuses are measuring normal.
The only thing that is consistent is that when there is a problem, the igniter doesn't relight. By that I mean that the igniter isn't relighting and waiting for the valve to open.

The only other symptom is that a few days ago, there was a noise coming from the valve area that sounded like it may have been clattering. It was a sporadic clatter. After that, the problems seemed to get worse.
Any ideas would be great.

Thanks,
Rob

[Gary/APP Team]

Hello. If you have replaced the coils and the igniter, to answer one part of your question , the igniter has to get hot and glow before the valve opens here is what you test for, Test for 3.2-3.6 volts AC at the gas safety valve with the igniter turned on. If the voltage is there, you have a bad safety valve. If the voltage is low, you have a weak igniter and the igniter will need to be replaced. You can test this with a Part number: AP3440648

Here is a link on how to use a multi-meter. Hope this helps. How To Check Continuity With Ohmmeter
next the sound that you are hearing at the valve is usually low gas pressure or empty tank I have seen it several times most likely this is it thank you and good luck

[rje45]

Where on the valve should I test for voltage? I'm seeing 120v image black and red wires (if memory serves) at the coils. When the igniter is charged, it flows very bright.
I don't have a tank, so I don't know how to check for low gas pressure.

Thanks for the reply.

Rob

[Gary/APP Team]

Hello Rob. Check the coils and see if they test good. You can test the coils using a multi-meter The two prong coil will read 1,000-1,300 ohms, and the three prong coil will read 1,300-1,400 ohms across prongs 1&2, and 500-600 ohms across prongs 1&3. Test the coils after running the dryer for about 10 minutes.

[rje45]

I'll test that as soon as I get home.
If the igniter doesn't light up after the first cycle, would that indicate a bad cool?

[Gary/APP Team]

Hello. Yes sir that would be right, thank you and good luck !

[rje45]

I tested the coils and here are the results:
Two-prong: 1400
Three-prong pin 1 - 2: 1409
Three-prong pin 2 -3: 590
when I started the dryer (from cold), it ran until the temp reached 30 degrees (c). The relay opened, the valve shut off. It ran with the valve off while the temp slowly continued to rise. After a few minutes, the relay closed and the igniter and valve came on. The valve stayed open until the temp reached 68 degrees. The valve closed and the dryer cooled to 58. I could hear the relay close again, but the igniter didn't come back on. The igniter is only two days old and burns great when it lights up. I tested the resistance across the igniter before and after the cycle, and it is good.
The strange thing is that the dryer will not heat at all after it cuts out on me unless I let it site for a long time (over an hour at least).

Any ideas?

[Gary/APP Team]

Hello Rob . You will need to replace the coils they aer breaking down.

[rje45]

Thanks Gary. I ordered some new coils. I had already orders a new thermistor before posting on here at the advice of a local shop. Of course that didn't work.since I replaced the thermistor, the igniter hasn't come on at all (with either thermistor installed). Hopefully I didn't screw something up when I did that.

What causes the coils to go bad? The coils in there now are only a month old. If the new ones come in and work, I'll get my money back. Is there anything that I can do to prevent the new, new coils from going bad after such a short time?

[rje45]

I think I found the culprit. There's a blown resistor on the controller. It looks like r54. I'm going to head to the electronics shop and see if I can replace it.