LG failed after repair

[JohnJacob]

Short version:
DLEX2501W high side thermostat failed. Replaced. Worked fine about an hour with heat. Heat stopped working again. Same symptoms as before: Runs 2 min with no heat, then error code nP.

Long version (and quite relevant):
Had an older Kenmore in same location working around 3yrs. High side thermostat went out, bought kit, and replaced several sensors/stats on heating element. worked fine.

Few months later, got used LG DLEX2501W w/bad roller. replaced roller, worked fine aprox 2yrs. high side stat went out. Failed with code nP. replaced stat. Threw code nP 1 time, then no code, and worked fine for about an hour. Again no heat and code nP.

I read that nP is wiring issue. Checked wiring on outlet, it was correct, however service panel had L1 and common reversed. Red on neutral, white on HOT! Yeah.... I promptly corrected that.

Anyway, I have not replaced the high side stat a second time, but I'm still getting nP and the 2 minute run time, even on 'Air Dry'

The authorized LG part is only $8, but I dont want to keep repeating the same mistake. Unit was no problem/worked well for 2yrs.

My concern is that incorrect wiring could have damaged the control board. Frankly I'm amazed we havent been electrocuted I'll throw another $8 at it blindly, but it's more about the time at this point. Ordering, waiting, disassembly etc.

Any hep would be appreciated.

[Pnwdad1981]

Most likely fried the board somewhere. Last time I saw that the pcb was a mound of melted plastic so if you don’t have to pry it out it’s a win lol. Check your venting too. You keep blowing the tco you gotta problem there too. Run a air fluff and physically put your hand on the vent. Theoretically hand full of dry grass in front of that vent should blow out if your hand with good flow. Even a complete restriction will put steam out on a cold day.

[JohnJacob]

First thank you for your reply, and the suggestions.

The hardline out of the house was installed 2yrs ago, its clear enough. The flex attached to the unit has to be long enough to remove and replace the unit, so perhaps 5-6ft stretched. I use a bit of kitchen string tied in the middle to lift and adjust the flex as I push the unit back into place so as not to block flow. It makes a few bends, but it doesn't crush or fold. Certainly not perfect, but the unit does have 'Flow Sense' some tech designed to detect restriction. No idea if it works, but FWIW, it reports no restriction.

The PCB is a snap to remove, and I have a background in electronics repair, so I will check that.

I notice this on the parts list:

Cycling Thermostat Assembly 6931EL3001F / AP5072172
"Dryers have a cycling thermostat assembly that is used to cycle the gas burner or heating element on and off, monitoring the temperature inside the blower housing"

However I assumed that was for GAS. This unit is electric. If equipped though, I am wondering if this has failed closed, overworked the high side thermostat, and is causing it to quickly fail.... My exp is that thermostats (of any kind) usually fail open but...

Looks like I have some work to do

[Pnwdad1981]

If it’s got a computer most likely uses thermistors to regulate heat cycles. They ohm out around 12-14kohms at 70ish degrees but of course they can fail from heat applied or it could be linty too if you take it out? Good luck.