HVAC intermittent ignite - I've tried a lot of things :)

Users who are viewing this thread

myownfanclub

New Member
Messages
3
Reaction score
0
Points
1
Location
Chicago
First time poster here. :)

I have an Armstrong Magic-Pak unit that doesn't ignite the flame each time.

It gets a correct call for heat and the blinking code is correct. It goes through the correct cycle: fan for about 20 seconds, gas valves open and then spark from an electrode ignitor. It's the sparking kind, not the glowing.

I can see visually a spark between the two electrodes but for some reason it just don't ignite.
If I take a lighter, I can light the gas and it works fine, so it's not as though there's no gas coming out of the nozzles. (I'm a handy homeowner so forgive me if I don't know all the right terms).

I can turn the thermostat down and back up and try again. Sometimes it works the next try, sometimes it takes a few tries. The unit is behind a refrigerator so I've had instances where I've tried and tried, then finally moved the fridge, sent the call for heat from my phone (it's a Nest thermostat), and opened the door to ignite it with a lighter and then it ignites itself. If you're thinking it's because the access door is open, then sometimes it lights when it's open and sometimes it just won't.

Here is what I have done:
cleaned the ignitor
cleaned the six horn-looking things that moves the gas (burners?)
ordered and tried a new igniter (back and forth a few times). The original seems better quality with copper instead of steel.

Lessened electrode gap on both igniters.
Tried blocking wind from outside to keep it from dissipating the gas in the chamber
cleaned the horn looking things that the gas moves into
Ran a new dedicated ground wire from the grounding screw to a piece of conduit ( the conduit is grounded)
The ground from that same screw goes into the circuit board so I added a direct ground.
Took the Nest off and tried previous LUX thermostat - same issues
Last Thanksgiving when I had someone out after all those things didn't work, he basically did them again. It worked a little but then went back to intermittent. He fried his meter checking the spark voltage.

It's four wires from the unit to the Nest but the fifth is for cooling, as you know ;)

I need ideas and answers if any of you have any.
I thought about adding a piece of galvanized steel above the electrode to pool the gas (like a BBQ grill has)
Is there too much draft? Not enough?

Lastly, I saw a sticker today that it's a unit for 240v, but if you have 208V then there's some wiring change needed on the transformer. Is that significant for my problem?

Like I said, when I light it with a lighter, it works fine.
 

WorthFlorida

Clinical Trail on a Cancer Drug Started 1/31/24. ☹
Messages
5,761
Solutions
1
Reaction score
997
Points
113
Location
Orlando, Florida
For residential property, 240v is the norm, for commercial property 208v is common. A 208 tap on a transformer is 8.6 to 1 ratio where as 240v is a 10 to 1 ratio to get 24 volts. 240x8.6=27.9 volts instead of 24v if it was tapped at 208 with 240v. Most 24 volt circuits will work from 18-29 volts. Usually without a load 24 volts will read higher than 24. Generally this never causes problems. If it was too far off the NEST would have had problems.

Sorry I can't help you with your ignition problem. Just be sure at the gas air inlets are clean with no spider webs, etc.
 

myownfanclub

New Member
Messages
3
Reaction score
0
Points
1
Location
Chicago
For residential property, 240v is the norm, for commercial property 208v is common. A 208 tap on a transformer is 8.6 to 1 ratio where as 240v is a 10 to 1 ratio to get 24 volts. 240x8.6=27.9 volts instead of 24v if it was tapped at 208 with 240v. Most 24 volt circuits will work from 18-29 volts. Usually without a load 24 volts will read higher than 24. Generally this never causes problems. If it was too far off the NEST would have had problems.

Sorry I can't help you with your ignition problem. Just be sure at the gas air inlets are clean with no spider webs, etc.


Thanks for your response! I did check the inlets and used a wire to make sure they are clear.
 

Reach4

Well-Known Member
Messages
38,882
Reaction score
4,433
Points
113
Location
IL
Some people have fixed water heater ignition by bending the ignitor closer to the flame area. I wonder if there would be an opportunity for something like that.
 

myownfanclub

New Member
Messages
3
Reaction score
0
Points
1
Location
Chicago
Some people have fixed water heater ignition by bending the ignitor closer to the flame area. I wonder if there would be an opportunity for something like that.

Thank you, I tried that last night and it worked right away. Then it stopped again with the same intermittent igniting. So frustrating. I'm going to try the same thing with the other electrode and switch them out.
 
Top
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) terrylove.com can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks