# Need help with sequencers going bad



## Aggie67 (Dec 20, 2008)

I am by no means trying to be snarky, but you know that saying "you've got your money's worth"? At 43 years of age, a 1972 furnace has exceeded its useful life. And if you know that someone rewired it, possibly wrong for that matter, then it's time for a new, much more efficient unit.


----------



## Mitchel85 (Nov 13, 2015)

*I understand*



Aggie67 said:


> I am by no means trying to be snarky, but you know that saying "you've got your money's worth"? At 43 years of age, a 1972 furnace has exceeded its useful life. And if you know that someone rewired it, possibly wrong for that matter, then it's time for a new, much more efficient unit.



Well I've only lived here a few years I understand it would be easier to just upgrade it, but at this point I don't have the money to spend a couple grand on a new furnace. If anything I will have to use space heaters in every room. When I'm allowed to post links, then maybe someone can see if something looks wrong.


----------



## beenthere (Oct 11, 2008)

How many KW of heater is connected to each sequencer.

In reality, a 1972 electric furnace is no less efficient then a 2012 electric furnace.


----------



## Mitchel85 (Nov 13, 2015)

beenthere said:


> How many KW of heater is connected to each sequencer.
> 
> In reality, a 1972 electric furnace is no less efficient then a 2012 electric furnace.


How do I find that out using a multi-meter? I know its a 24 volt sequencer with m1- m8 connections and it comes on in two stages. The fan and top coil turns on when the call for heat is sent, and then the bottom two coils turn on after that. It has 3 coils total with a 30 amp fuses and is a 220v furnace. I wish I could post some pics... This furnace ran fine for years with the way it's wired now, it's just the last year and this year that the sequencers have been going bad. I've bought them from Amazon.


----------



## beenthere (Oct 11, 2008)

With a multimeter. You would turn off the power/electric. And then ohm out each heater. Then divide the ohms into your power sourses voltage(208, 230,240, or what ever it really is. This will be the amp draw. Mulitply that by the volts, and you will get your wattage.

EG: 230 volts divided by 11 ohms=20.9 amps. 20.9 times 230 equals 4809 watts. So that would make a 4.8KW heater.

Its also usually listed on the heaters mounting plate. But not always readable.


----------



## Mitchel85 (Nov 13, 2015)

beenthere said:


> With a multimeter. You would turn off the power/electric. And then ohm out each heater. Then divide the ohms into your power sourses voltage(208, 230,240, or what ever it really is. This will be the amp draw. Mulitply that by the volts, and you will get your wattage.
> 
> EG: 230 volts divided by 11 ohms=20.9 amps. 20.9 times 230 equals 4809 watts. So that would make a 4.8KW heater.
> 
> Its also usually listed on the heaters mounting plate. But not always readable.


Ok, I got 10 ohms, multiplied by 233volts (Voltage was written on front by previous technician) so 23 amps ..and I get 5,428 watts.. So I guess that would be 5.8KW


----------



## beenthere (Oct 11, 2008)

5.4KW

Which is well in tolerance for a heat sequencer. What size/gauge wire is running from the sequencer to the heaters. Too small of a wire, can cause over heating of the sequencer.


----------



## Mitchel85 (Nov 13, 2015)

beenthere said:


> 5.4KW
> 
> Which is well in tolerance for a heat sequencer. What size/gauge wire is running from the sequencer to the heaters. Too small of a wire, can cause over heating of the sequencer.


Sorry, I meant 5.4kw. But the wires are all 10 ga. I have installed new wiring throughout this old house with new breakers and I'm pretty familiar with the basics and this is such a simple furnace..I'm going to order a brand name Emerson this time and spend an extra 10 bucks since I know it needs a new one anyways. Do you think I'm just getting bad sequencers since I have bought them from the same seller on Amazon which are generic for 15 bucks?


----------



## yuri (Nov 29, 2008)

White Rodgers/Emerson makes most of them and Pro's use them. What is the brand name of the Amazon ones? Hopefully not some no name Chineez knockoffs.

You should use stranded #10 wire and heat rated insulation. Same wire they use in electric stoves. Put brand new stakon connectors on. Most overheating is caused by loose connections. If you got stress on the sequencers from using solid wire or it is pulling on them then it will cause them to fail prematurely.


----------



## Mitchel85 (Nov 13, 2015)

yuri said:


> White Rodgers/Emerson makes most of them and Pro's use them. What is the brand name of the Amazon ones? Hopefully not some no name Chineez knockoffs.
> 
> You should use stranded #10 wire and heat rated insulation. Same wire they use in electric stoves. Put brand new stakon connectors on. Most overheating is caused by loose connections. If you got stress on the sequencers from using solid wire or it is pulling on them then it will cause them to fail prematurely.


The 10 ga is multi strand, and the only reason they melted before was because of bad sequencers not shutting off the coils so they got hot and melted. The cheap Sequencers didnt even have a brand, so most likely a chinese knockoff. I just ordered Emerson for 10 dollars more than the cheapo's so it was 26 bucks... 
I will update whenever I receive the new ones in the mail, and until then just turn off the furnace at the breaker when I need to heat the house as well as using space heaters. Thanks a lot for the help, and hopefully it was just a bad batch of sequencers that I've been getting.


----------



## WyrTwister (Jul 22, 2013)

Are the sequencers the klickson switches ? I have rarely messed with electric furnaces .

Some times the wire with the high temperature insulation can be a little difficult to source .

I agree , electric resistance heat is going to be the same efficiency , no matter what the model year of the furnace .

God bless
Wyr


----------



## Mitchel85 (Nov 13, 2015)

WyrTwister said:


> Are the sequencers the klickson switches ? I have rarely messed with electric furnaces .
> 
> Some times the wire with the high temperature insulation can be a little difficult to source .
> 
> ...


I just got out the old box and it says Packard.. made in China.. Timings 2 Switches -4 Type 2 -DPDT..

Yeah I realize now that it's going to use the same amount of electricity no matter what, so upgrading the whole furnace would be pointless.


----------



## Bob Sanders (Nov 10, 2013)

If you're using the sequencers with the flag connectors, make sure the female side of the connector (the connector on the wire) is in good condition and connects solidly. Taking them on/off enough times tends to loosen them and they don't fit snug anymore. This causes a heat buildup which warps the contacts inside the sequencer.

Those flag connectors (IMO) shouldn't be used on coils over 5k... too many problems with loose connections and heat because of it. If you can find sequencers with actual screw connectors where the wire wraps around the screw... much more solid. Rarely did I ever burn out one of those screw connect sequencers.... I had a hard time getting them though.

If you're feeling in the mood to do some modifications though....
I got tired of burning out sequencers and added relay contacts. I have now completely replaced my system but with my old system every time a sequencer went I would almost always overheat and burn a coil which was quite irritating.

What I did was simply connect a (properly rated) 24volt relay contacter to the sequencer. The output of the sequencer would supply 24volts to the relay contacter and the contacter would then supply power to the coil. I never lost another coil or sequencer after that. It was however a bit louder because you could hear the relay contact snapping in.

Interestingly enough on my new Goodman Air handler they have done away with sequencers altogether and the coils are run directly from relay contacters which get their timing from the main air handler board.


----------



## Mitchel85 (Nov 13, 2015)

Bob Sanders said:


> If you're using the sequencers with the flag connectors, make sure the female side of the connector (the connector on the wire) is in good condition and connects solidly. Taking them on/off enough times tends to loosen them and they don't fit snug anymore. This causes a heat buildup which warps the contacts inside the sequencer.
> 
> Those flag connectors (IMO) shouldn't be used on coils over 5k... too many problems with loose connections and heat because of it. If you can find sequencers with actual screw connectors where the wire wraps around the screw... much more solid. Rarely did I ever burn out one of those screw connect sequencers.... I had a hard time getting them though.
> 
> ...



there is actually an old relay on my furnace that has been disconnected. I just don't quite understand how I would wire that up, but I will look into it. As far as the connections to the sequencers.. I didn't see any that had a screw type connection and already placed an order, but always made sure they were really snug by crimping them with pliers while they were attached. I will look into the relay part though. Luckily I have smelled the coils over heating before they fried and went bad so I haven't had to replace those yet.


----------



## beenthere (Oct 11, 2008)

Are the wires connected to the sequencers getting brittle.


----------



## Mitchel85 (Nov 13, 2015)

beenthere said:


> Are the wires connected to the sequencers getting brittle.


I replaced all the ones that were except for one because I ran out of terminal ends.. I will get more and swap it out before I install the new sequencer just to be safe.


----------



## beenthere (Oct 11, 2008)

Also, you should use high temp crimp on connectors.


----------



## Mitchel85 (Nov 13, 2015)

beenthere said:


> Also, you should use high temp crimp on connectors.


Ok, I just used what I had laying around. Not sure what kind they are, but I will just go ahead and replace all of them with high temp connectors then. Thanks


----------



## Mitchel85 (Nov 13, 2015)

yuri said:


> White Rodgers/Emerson makes most of them and Pro's use them. What is the brand name of the Amazon ones? Hopefully not some no name Chineez knockoffs.
> 
> You should use stranded #10 wire and heat rated insulation. Same wire they use in electric stoves. Put brand new stakon connectors on. Most overheating is caused by loose connections. If you got stress on the sequencers from using solid wire or it is pulling on them then it will cause them to fail prematurely.


There are so many types of high temp wire that I don't know what to choose. At lowes they have THHN multi strand 10 gauge building wire.. Would this work, or should I order a different type online? It seems like that is what is in it now.. It only has the one layer of plastic/rubber sheathing around it.


----------



## yuri (Nov 29, 2008)

I am not sure what it is called. I go to a electric wire wholesaler that sells wire and supplies to the Electrical Industry and ask them and they know all the different names. They stuff I get is very soft and has a outer skin like a cotton covered wire in the old days. It is similar to what they use in electric stoves as that wire needs to be soft and flexible and heat resistant. If you have a apppliance repair store near you they may have it or else you have to try describe it to a electrical supplier. Doubt Lowes has it. Try post a qustion on our Electrical forum and someone may know how to describe it.

Or go to a scrap yard or dump and salvage some from sold old stoves as a last resort. Don't need many feet of it for a furnace.


----------



## Mitchel85 (Nov 13, 2015)

yuri said:


> I am not sure what it is called. I go to a electric wire wholesaler that sells wire and supplies to the Electrical Industry and ask them and they know all the different names. They stuff I get is very soft and has a outer skin like a cotton covered wire in the old days. It is similar to what they use in electric stoves as that wire needs to be soft and flexible and heat resistant. If you have a apppliance repair store near you they may have it or else you have to try describe it to a electrical supplier. Doubt Lowes has it. Try post a qustion on our Electrical forum and someone may know how to describe it.


Ok thanks.. I seen the kind of wire you are describing with the fabric looking material that is made from a type of fire resistant fiberglass. It sucks that I have to buy it in 25-50 ft rolls tho.. Stuff ain't cheap. Scrapping wire from something might be my best bet..


----------



## WyrTwister (Jul 22, 2013)

In the old days , it would have had asbestos insulation . But that is very politically incorrect .

This may be what you need ?

http://www.ebay.com/itm/10-HIGH-TEM...266906?hash=item3f09421b1a:g:90EAAOxy~hdR0u6p

It is available on eBay in different wire sizes .

Ebay also has high temperature crimp on connectors .

http://www.ebay.com/itm/50-High-Tem...927489?hash=item5aeddfdb41:g:ELsAAOxyXDhSf2nG

God bless
Wyr


----------



## Mitchel85 (Nov 13, 2015)

WyrTwister said:


> In the old days , it would have had asbestos insulation . But that is very politically incorrect .
> 
> This may be what you need ?
> 
> ...


I'm going to see if I can score some for free out of scrap appliances first, but yeah I guess that's what I need.. Even though it's not what is in it now.


----------



## WyrTwister (Jul 22, 2013)

We use THHN insulated copper wire all the time in general electrical . It may be OK for your furnace . I just do not know how hot that part of your furnace gets .

God bless
Wyr


----------



## Mitchel85 (Nov 13, 2015)

WyrTwister said:


> We use THHN insulated copper wire all the time in general electrical . It may be OK for your furnace . I just do not know how hot that part of your furnace gets .
> 
> God bless
> Wyr


It really doesn't get that hot.. It was only the times that the coils stayed on after the blower shut off from a bad sequencer that made the wires melt.. I should be ok with THHN if I can't find anything else. I will just make sure the connectors are new and secured properly.. I soldered one connector on, and Im thinking i will just do that when I replace the other wire that is slightly burned and brittle, and possibly solder the others just to make sure they aren't going to be loose at all.


----------



## yuri (Nov 29, 2008)

It may get pretty hot in the area the elements are. Heat will radiate from that area back to the wires plus with the amps they draw it all adds up. Pretty sure the elec code/ UL chose high temp wire for a reason.

I have seen 20 kw furnaces smoke up a house bad when all the wires melt and the elements short. I work on 20/25/30 kw furnaces and have seen lots of roasted burnt units.


----------



## Mitchel85 (Nov 13, 2015)

yuri said:


> It may get pretty hot in the area the elements are. Heat will radiate from that area back to the wires plus with the amps they draw it all adds up. Pretty sure the elec code/ UL chose high temp wire for a reason.


Yeah, I would like to make it as safe as possible. It just never had anything other than building wire in it since I've lived here and a HVAC guy who checked it out years ago never mentioned changing them. I will try to get some high temp wire whenever I can afford it if I have to buy it.


----------

