Nortron / Broan Electric furnace problem

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  #1  
Old 02-28-09, 07:46 AM
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Nortron / Broan Electric furnace problem

I had a new Nortron Broan Electric furnace fitted last October. Ran fine until a couple of days ago, when instead of kicking into the high speed fan /high heat setting, it runs at the low heat/speed setting as if on mild weather setting. I had the supplier come and inspect it, but as if to make a liar out of me it ran perfectly. That evening its back to it's old tricks again.
Rightly or wrongly, I hit the unit casing a tap with my hand, and 30 secs later it kicked into high settings. Now, I have no idea about these things, but I gather there are relays/ sequencers, and to me, it seems like one these of is sticking (hence the tap with the hand getting it to kick up to speed) I don't want to keep calling the guy back again and again, for it to work perfectly when he's here, but at the same time I don't want this to continue until the warranty runs out, so any ideas on how to track down the problem(when it is intemittent, at the moment) or if you have heard of this happening with a new furnace wheather Broan or not Thanks!
 
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  #2  
Old 05-20-09, 01:42 PM
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same problem?

hello...i have a 4 year old(give or take) electric 25 kw nortron furnace....the fan drops to low when the t-stat tells it to shut off....it stays on forever...only way to shut it off is with main breaker...no switches were tripped or touched......there are three switches on furnace itself...summer switch is set to heating.....energy saver switch is set to cold weather..... fan control switch is set to automatic....there`s also a green light on the furnace which sats t-stat on....t-stat controls are set to heat and auto....this has been like this all winter.....now fan won`t shut off...25KW, 240 Volt D Series Electric Furnace
Model 21D25....no model # written on furnace...not positive on model #....how do i trouble-shoot this problem so i can buy whatever part i need????which wires do i pull to test this and that?????please help....
 
  #3  
Old 05-21-09, 06:00 PM
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update.....i went back to the furnace with breaker on and the t-stat set to off...fan was running on low...i pulled the red fan wire and fan shut off and i saw the closest element start glowing red....that now explains the fan being on...i didn`t notice the element was on before because with the fan running,the element doesn`t glow as much...now my question is why is that element on with the t-stat set to off?thanks in advance,anyone?
 
  #4  
Old 01-02-13, 02:53 PM
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OMG I know this is an old post, but for the sake of anyone coming here to find an answer, I can tell you I had the exact same problem within a few weeks of having a new furnace fitted. Same thing - made a liar out of me when the guy came to look at it, then acted up almost as soon as he was out the door! He said that it was a sequencer, and ordered up a new one, fitted it ( under warranty ) , and ( touch wood ) its ran perfectly ever since ( that was late 2008 BTW ). Looks like it must have been a 2008 batch that was screwed up!
 
  #5  
Old 01-15-15, 06:26 AM
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Hello Guage123
I have the same problem. Fan runs at a low speed constantly, even after thermostat is finished its cycle.
I've changed the 24 volt relay and an element that had a cracked ceramic.
What sequencer did you change? the top or bottom?
I have a nortron 21b18
 
  #6  
Old 01-15-15, 07:35 AM
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Welcome to the forum! That unit also has a 240V fan relay. I have circled it in red in the attached photo. I suggest you carefully tap on the relay with the handle of a screwdriver to see if the fan will shut off.
 
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Old 01-15-15, 07:40 AM
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hello,
That was the other part I was considering changing. I'll give it a tap to see if it does anything.
 
  #8  
Old 01-15-15, 09:26 AM
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If you remove the wire going to the G terminal on the thermostat does the fan shut off? If so, that would point to an issue with the thermostat. If not, further troubleshooting will be required.
 
  #9  
Old 01-15-15, 05:49 PM
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Tried tapping the 240 volt relay, did nothing.

My thermostat wires are hooked to R and W1. None hooked to G from thermostat.

This a really old wire (2 lines)from the previous oil furnace. Running a newer 5 wire cable was to hard.
 
  #10  
Old 01-15-15, 06:20 PM
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My thermostat wires are hooked to R and W1. None hooked to G from thermostat.
The 24V relay you replaced normally has the wire from the thermostat G terminal connected to the coil, terminal number 1. The other coil terminal is labeled 3 and is connected to the common wire from the transformer.

If you follow the wire connected to the coil of the 240V relay you tapped you should be able to determine which sequencer is connected to the 240V fan relay.

Here is a link to the installation manual for your unit:

http://www.master.ca/documents/insta...ortron_eng.pdf

There are several wiring diagrams included in the manual. How many kilowatts are your elements?

On page 4 of the manual it shows that if the fan control is set to "continuous" the fan will run continuously at low speed. Have you verified the switch is not set to the "continuous" position?
It seems that since you do not have a G wire connected to the thermostat you would have to have the fan control set to "continuous" as the thermostat can't control the fan.

The last page of the manual has a troubleshooting guide.
 

Last edited by firedawgsatx; 01-15-15 at 07:27 PM. Reason: Added link
  #11  
Old 01-16-15, 05:56 AM
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Hello
It's not running continuous low. I have it switched to auto
It's running lower than low speed. Meaning if i do set to continous you hear the motor pick up speed.

I had the motor changed by a technician and it's not an original part. After he left I noticed that the fan kept going after the heat cycle finished, called him back, he spent 3 hours investigating. I told him to get lost when I felt he had no idea what he was looking for. He suggested it was either the 24 or 240 volt relay that was stuck. That day cost me a fortune and my furnace is still not up to par.

The heat comes on, but the fan blows in low speed only. I have to use the thermostat override switch for the fan to blow at high speed. I'm thinking the new motor doesn't like my wiring from my thermostat. Like I said, it's an old 2 wire setup.

So far I've changed the 24 volt, and an element. will go tonight for the 240 volt relay.

The diagram you posted is bit different than mine. My furnace is a 2005 model.
Part numbers have different numbers.
 
  #12  
Old 01-16-15, 07:38 AM
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Hopefully, the replacement motor has the same specs as the original. As shown in the wiring diagram for your unit, the blower speed is determined by which wires from the blower motor are connected to the relays. I would start with ensuring the wires from the replacement motor are landing in the same spot on both relays as the original.
 
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Old 01-16-15, 09:24 AM
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I thought of that
But the colors are the same. blue, red and black.
And the positions match the diagram
 
  #14  
Old 01-17-15, 05:10 AM
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Changed the 240 volt relay and the bottom sequencer. All wires are in their proper place.
Fan is still blowing after cycle. I'm at the point of calling it quits and calling a technician.

Only thing I see that is fishy is that I have a diagram for the new motor talking about 230 volt line, but everywhere on my furnace mentions 204 Volt. Could the new motor be the issue?
 
  #15  
Old 01-17-15, 09:45 AM
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Based on the fact that it was operating fine until a few days ago I would say it is not the blower motor.

Changed the 240 volt relay and the bottom sequencer.
According to the manual linked in post #10 troubleshooting guide #8 would suggest the top sequencer controls automatic speed change.
 
  #16  
Old 01-18-15, 10:10 AM
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Hehehe
I guess by process of elimination it could be the top sequencer! It's the only part I haven't changed.
 
  #17  
Old 04-16-15, 03:38 PM
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Okay here we go.

To the people who aren't hitting second stage, (only two elements on and slow fan speed), your secondary sequencer is pooched. It is the top doohickey that is on a mounting plate that looks like the other doohickey below it but the bottom one has two things on it instead of one. If you tap that top one and within 110 seconds you get stage to heating then that is your problem. People who's furnace does not shut off the bottom sequencer is toast and the contact is sticking. Just part of this contactor is not working so if you hear clicks out of it it could be other portions of it working. Most likely the top poles marked m1 & m2 is the running on problem. I have talked to people saying that there are generic replacement parts available to replace either of these but I personally have had the knock off parts be wrong for the application. Pay the extra for the real groan part. It's double the price but, at least in my experience works better. The bottom 3 pole should cast around $60-80. The top single post is about $40. If you can flip switches and get different fan speeds then the 24 & 240 volt relays should be ok. Before you play with any connections flip the breaker to you furnace off. There is a lot of power there and it will hurt you and further damage your furnace if you mess up. Once the power is off this is also a good time to remove and clean your elements. Clean elements save energy and therefore save you money. Hope I helped someone.
 
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Old 04-16-15, 08:55 PM
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Welcome to the forums.

Thanks for the additional information. I can see by the amount of page views that this is a hot topic and common problem. It's getting a little too long to reply to so it will be sent to our searchable archives where it will always remain available for reference.

If this thread doesn't help..... feel free to start a new thread where we will help you further.
 
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