Dryer Overshooting Temperature

[sqslabs]

I've been running my new dryer (Adelco JetForce 150S) for about 4 months now with no issues, but the past week or so it has started to overshoot the temperature that its set at by 10-20 degrees.  It has been getting a bit warmer here (its currently 80F), but I wouldn't think there's been so much of a change in outside temp that it would affect the dryer.  For the most part I keep the dryer at 360, and its currently hovering around 370-380.  I've tried adjusting the min flame but can't seem to get it dialed and I don't want to mess things up even more.

[ZooCity]

Do you have a regulator before your gas train?   We had the same issue for ahwile, installed a reg and solved it.  They need to be properly vented with smaller diam black iron or whatever is code in your area so a bit of a pain but have your hvac person do it if you haven't yet. 

I think that incoming pressure just fluctuates enough on the line to need some conditioning before it hits the dryer's gas train.  What I don't understand is why we sometimes have to adjust the regulator, that's over my head but it does work to solve the dryer overshooting temp.

[ebscreen]

PID might need to "re-learn" your operating conditions. Should be some buttons to push, if it doesn't do
it automatically. It can take a day or so for it to "get it".

Also, we've had the rod on the motorized valve control thing slip a bit before, and that'll throw you off.

[sqslabs]

Thanks guys.. We have two regulators outside the building and one right before the input of the dryer.  I'll take a photo in a minute of the internal setup to see if I am on the same page as what you're talking about. 

I did notice that when starting up from cold, it hits the temp and idles there for about 1/2 hour.  Than it starts to raise the longer the dryer is on, maxing out at about +20 degrees over the course of 2-3 hours or so..

Apologies for my ignorance, but what is a PID?

[californiadreamin]

SQ!
I would think it is a high gas pressure issue. What is the gas pressure coming in to your dryer?
You can try lowering your pressure regulator (open top turn to left to lower)
If you are already turned all the way to the top, you must lower your incoming from source.
Are you natural or LP?
Natural gas incoming pressures can fluctuate depending on Demand use with colder/hotter weather.
Gas companies usually turn up pressure in cold weather and lower in warmer on the gas grid.
If it by chance it is propane, It can be an issue with pressure buildup in hotter weather.
In South Florida This has always been an issue In which I tell people to put tanks under Shade to help sun
From Heating Up Tank. (Propane expands 11 times when it hits the Burner Flame) Which is why a minimum of Two
Regulators is normal for industrial use and natural gas usually comes in at 7" WC from the source which is why only
one Regulator is needed. If it is High Pressure Nat Gas, then two regulators are needed. I tell anyone putting in a gas oven of any
brand to always have a 0-15" WC gage on a Tee Fitting before final regulator so that the source of the gas can be monitored.
If gas is stable and correct and you still have problems, I would then check offsets on temp controller.
Winston
904.3430848

[sqslabs]

SQ!
I would think it is a high gas pressure issue. What is the gas pressure coming in to your dryer?
You can try lowering your pressure regulator (open top turn to left to lower)
If you are already turned all the way to the top, you must lower your incoming from source.
Are you natural or LP?
Natural gas incoming pressures can fluctuate depending on Demand use with colder/hotter weather.
Gas companies usually turn up pressure in cold weather and lower in warmer on the gas grid.
If it by chance it is propane, It can be an issue with pressure buildup in hotter weather.
In South Florida This has always been an issue In which I tell people to put tanks under Shade to help sun
From Heating Up Tank. (Propane expands 11 times when it hits the Burner Flame) Which is why a minimum of Two
Regulators is normal for industrial use and natural gas usually comes in at 7" WC from the source which is why only
one Regulator is needed. If it is High Pressure Nat Gas, then two regulators are needed. I tell anyone putting in a gas oven of any
brand to always have a 0-15" WC gage on a Tee Fitting before final regulator so that the source of the gas can be monitored.
If gas is stable and correct and you still have problems, I would then check offsets on temp controller.
Winston
904.3430848

Winston!
Thanks for taking the time to reply.  I'm going to look into everything tomorrow regarding the pressure and regulators and will report back with my findings.  We are using LP, but the unit contains a Nat Gas burner.  Not sure if that would have anything to do with it, but realized I forgot to mention that in my original post.

I hit the tanks outside with a temp gun today and they were right around 80 degrees and in the shade when the temp started jumping beyond its setting.  I didn't have a chance to keep checking throughout the day but will do so tomorrow.

Thanks again!

Brett

[californiadreamin]

Brett, Glad to help!
Most, but not all burners in dryers are dual fuel. Since LP Burns hotter than natural, and under compressed
pressure it normally will run and operate at lower water inches to natural gas. Old burners used to have "jets"
which meant the burners for natural had larger orifices, and LP had smaller orifices and were interchangeable
depending on the fuel type. Your burner should work fine, only adjust to lower pressure on incoming gas.
Hopefully it will fix your problem. Your issue is somewhat common, so it is not just you and your dryer.
A incoming pressure gage will tell all.
winston

[californiadreamin]

FYI
Gas Pressure Gauge (Helps Monitor Gas Train Functions
Grainger Part# G3997 (Specify 0 to 15 H2O)  About $38.00

[sqslabs]

Brett, Glad to help!
Most, but not all burners in dryers are dual fuel. Since LP Burns hotter than natural, and under compressed
pressure it normally will run and operate at lower water inches to natural gas. Old burners used to have "jets"
which meant the burners for natural had larger orifices, and LP had smaller orifices and were interchangeable
depending on the fuel type. Your burner should work fine, only adjust to lower pressure on incoming gas.
Hopefully it will fix your problem. Your issue is somewhat common, so it is not just you and your dryer.
A incoming pressure gage will tell all.
winston

Thanks Winston, that's great news.  I'm going to make the adjustment to the regulator but after looking again today there are actually 4 regulators between the tanks and the dryer.  Two outside the building, and two inside the dryer.  I'm going to assume that the one to adjust is the final one in the chain, but just wanted to make sure before moving forward.  I've attached pics of each regulator's specs, and will follow this post with another which shows the internal setup. 

I also noticed today that the gauge inside the dryer, placed just after the final regulator shows no movement even when the dryer is heating up. Not sure if its a Nat Gas gauge and that's why, but figured I'd mention it.  I'll also grab the gauge you linked to and get that installed prior to the final regulator.

[sqslabs]

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[244]

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None of my business but looking at your guage the needle is pegged past all recognition. That is a lot of pressure!!!

[ebscreen]

Oh snaps, you done went all the way around the dial!

[sqslabs]

None of my business but looking at your guage the needle is pegged past all recognition. That is a lot of pressure!!!

Holy crap thank you for pointing that out.  I didn't realize it was on the other side of the peg!!  No wonder it never moves!

I guess my HVAC guy wasn't too bright.  So I should be able to adjust this on the final regulator in the chain, yes?

[Binkspot]

Just a few observations.
The vent should not be plugged on the regulator, that alone could be the issue. I do not think they can be adjusted. Why is there a mix match of galivinized and stainless pipe?

[sqslabs]

Alright, so I think I got it dialed in.  I adjusted the pressure on the final regulator significantly (it was set almost all the way high), which allowed me to adjust the min/max flame on the sol valve.  Before adjusting the regulator, the flame was so powerful that sol valve adjustment didn't do anything.  I was able to get the top end to a steady 360 and the low end to 240, which works for us.  We often run nylon bags at 250 and have been having to turn the flame on/off manually to maintain that temperature on our last few runs.

The only con is that the dryer no longer gets up to temp in under 2 minutes. 

Oh, and as far as the pressure gauge needle, it still hasn't budged even when we turned off the gas completely and flushed it.  Weird.