My Garage/Shop Heater Install

[dragoneggs]

You try to move the flame sensor or see if its loose .........

Flame sensor seems secure. Thinking of removing and reinstalling. Since I can't see the flame chamber there is no way to see if it is in the flame but worth monkeying with it at this point. Maybe try to point/angle it down some? :confused3: Not easy to get a tool on the screw... especially with my XL hands. Going back out. Left my 9mm inside. :laughing:

 

[BukitCase]

I think we're getting some terms confused here - the flame ROD IS the flame SENSOR, when it sees a flame it rectifies a portion of the high AC voltage; this smalle DC voltage is what causes the microamp current from the flame rod back into the control board.

The flame ROLLOUT is actually an OVERTEMP sensor; it's resettable, trips if things get too HOT. Works just like the overtemp in your clothes dryer (usually 2 of 'em, 1 in exhaust and a second on the back plane)

Since the flame rod will NOT see the sparks from the ignitor, it's possible that the piezo spark generator just keeps sparking til the 16 second "flame proving" circuit times out.

If, at the end of the 16 second attempt at lighting, the flame rod circuit isn't satisfied (this is what runs the yellow led circuit), the control will shut off the gas. Some units require you to re-start the cycle, yours may be automatic when room temp is below setpoint; don't recall.

The way this heater is set up makes EVERYTHING a PITA for troubleshooting; so far, the only way I've seen that you know if you EVER get an actual flame is by checking the temp of the burner tube.

And yeah, PITA being recognized - but the only way I can think of to run this down is to VISUALLY see if, during a lighting attempt, there is not ONLY a flame, but what does it LOOK like? (long, short, thin, fat, mostly blue or lots of yellow, etc)

From the drawings and your pics, it looks like taking the flame rod out (and isolatinging the wire to it, likely 3-400 volts AC) that you may be able to hold an inspection mirror up to the flame rod hole and see if there's flame. (Of course this would only happen for 16 seconds)

There's times when this stuff got a bit hairy even for me after doing it for over three decades; so if it's stressing you too much it may be time to get some local help (if they'll even do service calls during the current situation) - but as long as you're game, I'll stay with it. I'll also warn you of anything that might not be an obvious safety concern... Steve

Sorry, SWMBO interruption while typing; I'll check back in a few...

 

[dragoneggs]

Removed and tweaked the flame sensor rod to angle down a little (towards the flame). Same result. Wondering if measuring voltage on the sensor is worth trying?

 

[BukitCase]

YES - please measure during ignition attempt, check it on AC (around 300 volts or so) and again on DC (should be around 20+ volts DC) - BOTH readings should be done on NOT auto range. Also note whether the DC is + or -...

I need to know if there's anything "hinky" about this unit I'm missing... Steve

Soooo, there's no way you can get a small mirror in line with the flame rod hole so you can look at what the (removed) flame rod is looking at?

 

[dragoneggs]

I think we're getting some terms confused here - the flame ROD IS the flame SENSOR, when it sees a flame it rectifies a portion of the high AC voltage; this smalle DC voltage is what causes the microamp current from the flame rod back into the control board.

The flame ROLLOUT is actually an OVERTEMP sensor; it's resettable, trips if things get too HOT. Works just like the overtemp in your clothes dryer (usually 2 of 'em, 1 in exhaust and a second on the back plane)

Since the flame rod will NOT see the sparks from the ignitor, it's possible that the piezo spark generator just keeps sparking til the 16 second "flame proving" circuit times out.

If, at the end of the 16 second attempt at lighting, the flame rod circuit isn't satisfied (this is what runs the yellow led circuit), the control will shut off the gas. Some units require you to re-start the cycle, yours may be automatic when room temp is below setpoint; don't recall.

The way this heater is set up makes EVERYTHING a PITA for troubleshooting; so far, the only way I've seen that you know if you EVER get an actual flame is by checking the temp of the burner tube.

And yeah, PITA being recognized - but the only way I can think of to run this down is to VISUALLY see if, during a lighting attempt, there is not ONLY a flame, but what does it LOOK like? (long, short, thin, fat, mostly blue or lots of yellow, etc)

From the drawings and your pics, it looks like taking the flame rod out (and isolatinging the wire to it, likely 3-400 volts AC) that you may be able to hold an inspection mirror up to the flame rod hole and see if there's flame. (Of course this would only happen for 16 seconds)

There's times when this stuff got a bit hairy even for me after doing it for over three decades; so if it's stressing you too much it may be time to get some local help (if they'll even do service calls during the current situation) - but as long as you're game, I'll stay with it. I'll also warn you of anything that might not be an obvious safety concern... Steve

Sorry, SWMBO interruption while typing; I'll check back in a few...

Steve, I have a flame sensor AND a flame rod. The flame rod may also include a sensor but see pic. The sensor is several inches above the flame rod. You can see them both along with the rollout switch. See the blue flame during ignition. That is best indirect view I have. No access to actually see it.

 

[ultrarunner]

I've used phone camera/video before for places I just could not see.

 

[dragoneggs]

YES - please measure during ignition attempt, check it on AC (around 300 volts or so) and again on DC (should be around 20+ volts DC) - BOTH readings should be done on NOT auto range. Also note whether the DC is + or -...

I need to know if there's anything "hinky" about this unit I'm missing... Steve

Soooo, there's no way you can get a small mirror in line with the flame rod hole so you can look at what the (removed) flame rod is looking at?

Nope no mirror that I know of... maybe a boroscope is in order?

I can get to some metal on the flame sensor but the flame rod looks completely insulated. That is if I know what I am talking about.

 

[BukitCase]

OK, the furthest away item (white insulator showing, single wire) is the flame rod.
The closer item (little black and red button in middle, 2 wires) is what the manual calls "flame rollout" (AKA "overtemp" in MY world :=) Not really a flame "sensor", just a HEAT sensor. That little button is the RESET, should the unit go overtemp.

Can't see from the angle the pics were taken, does the white insulator on the flame rod extend far enough to ALSO insulate the rod from the burner tube?

Also, if the blue light in the pic is the flame, I'm not seeing any obvious problem unless it's in "excess air" (very lean flame) but that might be normal for "greenie" stuff...

 

[dragoneggs]

OK, the furthest away item (white insulator showing, single wire) is the flame rod.
The closer item (little black and red button in middle, 2 wires) is what the manual calls "flame rollout" (AKA "overtemp" in MY world :=) Not really a flame "sensor", just a HEAT sensor. That little button is the RESET, should the unit go overtemp.

Can't see from the angle the pics were taken, does the white insulator on the flame rod extend far enough to ALSO insulate the rod from the burner tube?

Also, if the blue light in the pic is the flame, I'm not seeing any obvious problem unless it's in "excess air" (very lean flame) but that might be normal for "greenie" stuff...

Wife said stop. It's time for dinner. Cabbage soup and a salad. Have another pic I will send that will help 'explain' after dinner.

 

[BukitCase]

Missed this the first time; there's ALSO a "limit control", it's the small sensor near the center of the first pic (2 wires, 1 goes to the flame rod) this is essentially a "thermal fuse", normally would OPEN on a higher temp than the "rollout". If that one is OPEN, you buy a NEW one. If it IS open (bad) you'd most likely NEVER see a flame rod signal at the control board. Can't tell if that's wired with spade lugs; if so, you can pull one side and check continuity. Should be nearly a dead short.

Usually the two sensors in a clothes dryer are the same; the one on the back plane is resettable, and (at least on older ones) controls the heating elements - the one in the exhaust path is DONE if it overheats... Steve

OK, ignore MOST of this post; got a better look at othe pics, flame rod signal does NOT go thru those temp sensors - sorry...