York Stellar Furnace - HSI won't glow !


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Old 11-24-12, 12:30 PM
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York Stellar Furnace - HSI won't glow !

50E47-070 Control providing 125 VAC to IGN and one side of HSI Ignitor.

Voltage read at ignitor is only 30 VAC across plug, but IGN side has 125 VAC during ignition sequence.

Gas being provided - pressure switches must be ok. Draft inducer is ok.

Starts Manually: Lighting the gas with a BBQ lighter provides combustion up to
"pause / break" of furnace during normal heating... runs for
5 minutes or more.

No glow on HSI to ignite gas normally.

Replaced HSI - still no glow.

Suspect Neutral side of HSI circuit - as IGN from controller is 125 VAC

Traced to relay below Control board.

Replaced relay.

Still runs ok "manually lit" ... but no glow on HSI.

HSI voltage now reads 25-30 VAC.

Fusible Link checks ok for continuity.

Does safety switch on panel actually do anything ?

Runs whether in place or not.

Any ideas on the HSI not glowing ?

I'm down $75 at this stage... trying to DIY it.

Thanks in advance.

- Hugh
 
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Old 11-24-12, 12:50 PM
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When you checked the voltage to the HSI.....you found 125 vac to ground on one leg when unit was demanding the HSI to light and no voltage when idle. That would suggest you lost a neutral like you thought. My guess is you're going to find a defective solder connection at the multi-pin connector.
 
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Old 11-24-12, 01:00 PM
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Thanks for the reply.

Yes... thermostat requesting heat.

125 VAC across HSI "IGN" leg and casing... (GND).

But 30 VAC across both legs of HSI supply cable.

Regardless of where measured... the voltage goes away as normal when Controller says so.

The 30 VAC reduces to 5 VAC or under.

The 125 VAC from controller (as measured wrt GND) goes to near Zero.

Continuity of neutral goes to relay...

... (new & old) relay seems to oscillate make my meter tone "twitter" as opposed to a continuous tone. Might be a red herring of the meter and the AC cycle.

Any other thoughts ?
 
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Old 11-24-12, 01:08 PM
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My diagnosis stays the same based on issues I've seen with those control modules.

My guess is you're going to find a defective solder connection at the multi-pin connector.

Look at the board. There are two wires that are used in the multi pin connector for HSI. One is hot leg and goes to one pole of the relay. The other one should go to a common neutral area.


P.S. Always good to have a spare HSI
 
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Old 11-24-12, 01:52 PM
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You say "look at the board".

Do you mean connector at Controller ( "L" and "IGN" markings) or
at the HSI itself ?

Thanks again.
 
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Old 11-24-12, 08:29 PM
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You likely need to replace the control board. DO NOT attempt a repair on an ignition control board!
 
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Old 11-25-12, 03:10 AM
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The controller seems to correctly put
125 VAC out on the IGN pin - connecting
to one side of the (new) Hot Surface Ignitor.

Voltage across bith Ignitor pins is 30 VAC,
but can measure the 125 VAC between
IGN side and case (GND).

Suspect neutral side.

Controller:

http://imgur.com/WlOWW.jpg

Relays: (left side is newly replaced)


http://imgur.com/M4eNH.jpg
 
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Old 11-25-12, 05:56 AM
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yes, replace the control board. I can't be any more clear than that.
 
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Old 11-25-12, 07:37 AM
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But controller seems to be operating correctly - 125 VAC out of IGN.

IGN drops to 0 VAC after 30-45 seconds.

Seems to be correct behavior.

Whole ignition sequence seems ok - bar
no Hot Ignitor.

Any other tips ?

I suspect neutral side of HSI ?
 
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Old 11-25-12, 08:23 AM
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is the neutral side of the HSI circuit not coming out of the control? You have not been clear on how it is wired. We are just guessing without a schematic and going just by your description.
 
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Old 11-25-12, 09:06 AM
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Now that you've provided a pic I can see some conflicting issues. First off.....those two relays have nothing to do with the ignitor. One is the main blower motor and the other is the draft inducer blower.

If you look at the 50E47 control box in the lower right corner you'll see a two pin plug. Looks like red and brown in your pic. One of those two pins is labeled L1 and that's 120 v in. The other pin is labeled IGN and that's the 120 v to the ignitor.

I believe you'll find the ign wire is red and the other HSI wire would be orange. The orange wire goes directly to the neutral splice. If you can't find the neutral splice .. look for the white coming in from your main power source.


If you take off the blower door the schematic is usually posted there on York units.
 
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Old 11-25-12, 09:34 AM
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Fixed it !!!

Re-did the neutral splice - and HSi glows beautifully !

Used a wire nut (yellow)

Thanks for all the suggestions !!

http://imgur.com/bYD79.jpg
 
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Old 11-25-12, 09:36 AM
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Great news. Time to sit down and enjoy.
 
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Old 11-25-12, 09:52 AM
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Well - maybe.

Ignitor lit once.

Watch this space ...
 
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Old 11-25-12, 07:37 PM
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Seems like on a successful ignition the furnace runs ok for
5 minutes or so - then blower fan stops - inducer still running,
but does not seem to want to ignite.

Run time increases temp by 1 degree or so.

Flame Sensor seemed clean.

Inducer motor starts a tiny bit sluggish - but does start
allowing first ignition. So pressure sensor was happy.

How do I test a pressure sensor ?

Do they close or open circuit ?

Can an inducer motor be nursed ? Serviced ?

Thanks in advance !!!
 
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Old 11-25-12, 08:46 PM
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The inducer motor runs under great heat. Not much of a way of nursing them and I'm not even sure you could get oil into it.

The pressure switch on York furnaces uses both normally open and closed terminals. Put your meter on it and start the heating sequence and see what it does. Mine has 3 orange wires and 1 brown wire on it. The switch should be labeled quite clearly.
 
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Old 11-25-12, 09:35 PM
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PJ,

Thanks for the reply.

Is the heating cycle Heat - Rest - Heat - Rest.

Funace runs for about 5-10 minutes with Blower
running - then no combustion and only inducer.

Limit switch behaving normally ?

Not re-igniting is weird. Maybe Inducer RPM slows and
pressure sensor kills gas. If RPMs don't recover - no Ignitor - no gas ...

Is the inducer a Fasco A307 ?

Thanks for ideas !
 
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Old 11-27-12, 03:46 PM
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Fix #1 - loose crimped junction on Neutral (white wires) at base of unit.

Fix # 2 - blocked condensate "trap" at base of unit. Black box thingy. Washed it out.

Thanks for all the Views and Posts !
 
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Old 11-11-14, 10:47 PM
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This thread will always be available for future reference.
If you have further questions on your particular system... please start a new thread.
 
 

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