Home furnace problem, need advice

[Andy Perreault]

Anybody work on home furnaces here? My furnace (electric forced air) has been acting up in the last few days. Yesterday morning while I was still in bed, I could tell that the house was unusually cold. I got up to investigate why, and I found that the heating element was on but the blower was not. I turned off the circuit breakers, because the whole unit was awfully hot. After letting it cool down, I turned the circuit breakers back on, and it worked fine. When I got home from work, I found the house was warm, so I figured it was just a one time anomaly. However, around 4 this morning, the same thing happened again. On the unit, there is a rocker switch that says “Auto” (the setting which allows the thermostat to control it), and “Fan”. The “Fan” setting will turn the fan on all the time, with or without heat. I found that by putting this switch in the “Fan” setting, the blower will come on and stay on. I set it this way and went back to bed for a couple of hours. When I got up for good, I set the switch back to “Auto” and the blower worked okay, coming on and going off as the thermostat dictated. But, after a few hours, it went back to the same problem of the heating element turning on but not the blower.

I found that the unit has quite a layer of dust in it, so I vacuumed it out as best as I can, but it is located in a narrow cabinet and hard to reach into. The blower unit is removable, and there is a sticker on it that says to remove the blower and clean it once a year. I would like to do that, but there is one thing that worries me, because I’m not that knowledgeable on electricity. There is a large capacitor on the blower between the power supply and the motor. According to the parts diagram, the specs for the capacitor are “7. 5 MFD 370v”. I don’t want to get zapped by 370 volts that may be stored in that capacitor. By unplugging the connector for the motor wiring from the electrical panel inside the heater (so I can remove the blower to clean it), will I damage the capacitor or get a shock?

This unit, a “Nordyne model E2EH-017HA” is in a six year old manufactured home that I have lived in for three years. I found a parts diagram, but I do not have any kind of instruction manual or troubleshooting guide. I suspect the blower relay may be faulty. What do you think? Could that capacitor be bad? I’m guessing the capacitor is used to get the motor started, but I’m no electrician.

However, if the blower relay or capacitor are bad, then howcome the blower comes on just fine when I flip the switch to “Fan”? There is only one pair of wires that comes from the thermostat. The thermostat (low voltage 24v) seems to be working just fine, because the heater element will come on and go off, but for some reason the blower occasionally doesn’t turn on when it’s supposed to.

Right now it’s working just fine. I keep the heater on while I’m at work to keep Charlie the cockatiel warm. However, I don’t like the fact that the heater may come on without the blower while I’m not at home, because the whole unit gets extremely hot when that happens.

Thanks for any help.

Andy

 

[loncray]

This might be a stupid question, but did you change the filter? My A/C unit froze up because I'd let the filter go too long and airflow was blocked. Yes, you must keep your 'tiel warm - I've got two of them and they don't care for the cold. I'm afraid I can't answer the question about getting shocked - maybe turn off the breaker, wait an hour or so for the capacitor to discharge, and have somebody nearby to help if anything goes wrong?

 

[ToolManTimTaylor]

The cheapest route is a start run capacitor. @ 6 bucks it can make or brake you. That is THE #1 problem I have had on all 470 units I have worked in. . . including my own home however without it I finaly burned a motor as I got that Ahhhh I'l fix it later attitude. a 7. 5 microfarad cap is about 6 dollars.



Start / Run Cap

 

[outlawram]

I had a problem like that last year. I replaced the capacitor and it worked great after that. For 6 bucks it was money well spent. I just made sure while unhooking it i did not let it arc across. I am still alive so All is good.

 

[Andy Perreault]

Thanks for the replies. I'll try replacing the capacitor first. If that doesn't fix the problem, well, I'm only out 6 bucks and I'll have a spare capacitor.

Yes I did change the filter. I was hoping that the clogged filter might have been causing some overload switch to trigger or something like that, but no such luck. That filter had been in there a year. I noticed on the packaging that came with the new filter that it says to "replace after 3 months". Whoops, okay, from now on I'm marking the calendar.

As I'm writing this, the furnace is working fine. I kept it turned off while I was at work, just in case, and I was surprised that the house didn't cool off that much. Maybe I'll do that on a regular basis, because my electric bill is pretty enormous with having an all-electric house. I have a small space heater that I can put near the bird cage to keep "Mr. Grumpy-Wumpy" warm. Oh, he's a mean old unappreciative S. O. B!

BTW, last Saturday I bought a wood-burning stove, but I don't have it installed yet. I recently bought a generator, so once the stove is in, I'll be set for the inevitable power outages in my semi-rural neighborhood this winter.

Thanks again, Andy

 

[ropinfool2]

The fan is normally turned on by one of two ways, time delay or temperature activated. Once the t-stat calls for heat, the element will start to heat up. Now depending on which control system you have, the fan will either start after a specified amount of time or after the plenum has reached a set temperature (you don't want cold air blowing out). So it sounds to me like the time delay relay or the temp relay is faulty. If the motor starts up with the fan only switch,(I would try it multiple times) the capacitor is probably not at fault. I would also replace the overtemp safety switch, it should have shut that baby down when it started to get warm. Good luck. John

 

[Andy Perreault]

Ropinfool2, I agree with what you say about the possibility of a faulty relay, because the fan always came on when I manually switched it on. Yesterday, I removed the entire blower unit, dismantled it, and cleaned it. There is a sticker on the unit that says "remove and clean blower annually", and I've never done it since I lived here. I know that the previous owners never cleaned it. In fact, when I moved in here, I found that they were running it without a filter. Everything was coated with 6 years of dust and crud. I spent most of the day "detailing" it, and when I finished, it looked like it was brand new. After re-installing it, I flipped the circuit breaker on to see if it would work. Well, it worked just fine overnight. It would kick in and shut off just like it's supposed to.

So, I got to wondering: Do you suppose that all the dust inside the motor and all over the fan wheel and other parts was creating just enough resistance that the capacitor couldn't provide enough "oomph" to get the motor started? I blasted a lot of dust and crud out of the motor with compressed air.

Thanks TimToolManTaylor for the link to a replacement capacitor. I'm going to get one just in case. In the meantime I will monitor the heater closely, but for now it seems to be working just fine.

BTW, I found a parts page on the manufacturer's website, and they want $67 for the capacitor!

Thanks to all for your help, Andy

 

[HoleshotHolset]

Andy,



Welcome to the 'TDR Furnace Fighters Club'. If it wasn't for the TDR - I would have spent a BOATLOAD of coin having someone come and fix the furnace at my place.



Many late nights were spent on the TDR Chat and I also got lots of good advice in my "1850's house" thread. I'm 110% confident that the TDR gents will get you up and running in no time.



Matt - would be lost without the TDR

 

[dseabaugh]

I believe it is a limit switch that turns on the blower when the plenium reaches a preset tempereature and kicks a relay that juices the fan. It also does the same thing so it can cool down. That is also why when the coils ( electric) or fire (gas) shuts off a and the fan keeps running for a few minutes to let things cool down . This drops the temp enough to shut the switch off. It the fan runs when turned to fan it is not the start capacitor. If it is electric it may have an electic timer or even a mechanical one that rotates around and kicks in a relay that turns on your fan. At any rate , if it has a timer instead of a limit switch to start the fan, it should have a high limit switch that shuts things down if it over heats. Some of the older units didn't have the high limit switches to shut it down to prevent a fire, only low limit to turn fan on at a preset beginning temp. Some units have even had Sail switches that won't turn on the heat source unless the fan is pushing enough volumn of air to push the flapper enough to trigger the micro switch.

 

[JohnE]

Andy;

Do you have any buddies in the HVAC business?

I could not find a Puget Sound parts house that sells over the counter which creates a problem to find reasonable pricing on basic parts. Many HVAC companies will not sell just parts due to liability issues. BTW, Never call George Brazil (sp?). They ... are your last option.

Sometimes, Reliable Parts in Tukwilla can get HVAC parts. Worth a call. I still order my appliance parts from them.

When I lived in Auburn, a neighbor that worked HVAC got me parts at his cost which really helped. He even drove in to work one day when he had the flu to get me a furnace igniter. It burned out Friday and by Monday the house was really cold.



ropinfool2 gave great advice.

It appears you have failure of 2 separate circuits. Element over temperature and blower controls.

Dust does not usually affect timing systems except in the over temp sensors. The manual fan switch powers the main relays so they must work and the blower motor is OK (capacitor) as ropinfool2 suggested.

In a timing system the circuitboard often fails. The circuit board usually has a primary relay that powers the main blower relay.



Drop me an email if you have any more problems or questions.



-John

 

[Andy Perreault]

Andy,



Welcome to the 'TDR Furnace Fighters Club'.

Suddenly I'm reminded of the movie "A Christmas Story" where Ralphie's dad was down in the basement swearing at the furnace and banging around while the narrator's voice says "My old man was the most feared furnace-fighter in all of northern Indiana... "

Thanks again, everyone. Once again the TDR membership pays for itself. JohnE, my neighbor told me to try Reliable Parts. I bought some stove parts from them a few months ago. TimToolManTaylor's link posted earlier in this thread takes me right to the capacitor on the Grainger website and it's only $6.

I just came home from working overtime and the heater is still working just fine. It's been over 24 hours since I dismantled and cleaned everything. Maybe that's all it needed. Money spent so far: $0.

Andy

 

[ropinfool2]

Well hopefully everything continues to operate as it's supposed to. When I lived in Wa. I was told you couldn't buy furnace parts without a HVAC license (tried to buy some parts to fix an aunt's furnace). Something about liability. I ended up buying them from a buddy in Vegas. Hope your good luck continues. John

 

[HoleshotHolset]

Suddenly I'm reminded of the movie "A Christmas Story" where Ralphie's dad was down in the basement swearing at the furnace and banging around while the narrator's voice says "My old man was the most feared furnace-fighter in all of northern Indiana... "

EXACTLY! That's one of my favorite movies... EVER. I'm darn proud to be a 'furnace fighter'. I can "weave a tapestry of obscenities that's still hanging over Lake Michigan" just like Ralphie's old man. :-laf



Some people work in pastels... not me... I use obscenities.



Matt - $@^!*&

 

[Paychk]

TimToolManTaylor's link posted earlier in this thread takes me right to the capacitor on the Grainger website and it's only $6.

The only problem is Grainger is a wholesale only place.

 

[JohnE]

The only problem is Grainger is a wholesale only place.

Andy;

Grainger in Kent/Tukwilla sells OTC to Boeing employees. Maybe you can fib and say you left the badge at home. It may work.

 

[Andy Perreault]

Andy;

Grainger in Kent/Tukwilla sells OTC to Boeing employees. Maybe you can fib and say you left the badge at home. It may work.

They supposedly do that for FedEx employees too, according to an announcement my manager read out loud in a meeting.

The heater's still working fine tonight.

Andy

 

[ToolManTimTaylor]

Grainger is open public. I have two accounts with them and have still called in parts as a nobody mr off the street guy and had em drop shipped to my door (Lazy guy that I am and being the are only 10 minutes away LOL!)

 

[Andy Perreault]

Just thought I'd give y'all an update. A few days after my last post, I came home from work and found that the blower was not coming on again. So I got a replacement capacitor from Grainger and put it in. It worked... for one day! So, I took a cover plate off to get access to all the relays and wires (with the circuit breakers off, of course). The sticker on the cover has some warning about "no user-servicable parts inside. " I traced the wires from that "fan on-auto" switch and looked for loose connections. Out of curiosity, I turned the breakers back on. The blower still didn't work. I took the handle end of a screwdriver and tapped the relays, thinking maybe one was stuck. But when the screwdriver handle bumped a blade-type connector on a relay (the wire goes to the fan switch), suddenly the fan came on! So, I shut the breakers off and vacuumed the dust off all the wires and relays and checked all the connections. I crimped that particular female connector a little tighter and pushed it back on. That seemed to have cured the problem. It's been a couple of weeks now, and the furnace is working just fine!

Total money spent: $6 for a capacitor that I guess I didn't need. Oh, well, that's fine because now I have a spare capacitor. I'm sure happy that I didn't have to pay a couple of hundred dollars to have some serviceman come here and fix it. He could have taken me for a ride by saying something like, "Looks like you need a new motor, that will cost about $600. "

Anyway, thanks again for all the help. You guys definitely saved me at least a hundred bucks or whatever an HVAC guy charges nowadays for a service call.

Andy

 

[ropinfool2]

that's all right Andy, if we ever make it over we'll drink more than $100 worth!! John