Carrier 40AO036330EH

[mbonfa1]

Hey guys.  I'm not 100% sure on that model number as I was using a flashlight in an attic, sideways, holding myself up by a beam, and reading a 25 year old tag on the unit...  Everything is right except the O's may be zeros and vice versa.

The problem is it blows semi-warm air at best and takes forever to heat up the house (the house is really small).  Also, when it finally hits the correct temp, it won't turn off by itself.  The A/C shuts off properly and cools properly.  Can someone please point me in the direction of a good start?

[applianceman18007260692]

Sounds like you have a bad fan relay. That relay is stuck in cool mode and the fan is running on high speed. The job of the relay is to switch the fan from low to hi for ac. When the heat comes on the fan is supposed to be on low speed(red wire mostly) When AC is activated this relay moves the fan speed to the hi (black on the motor most of the time). The relay can stick into the hi speed mode. Just guessing.

[mbonfa1]

Ok, forgive me for being ignorant.  After some research, I understand why the relay switch needs to be changed because the blower won't respond to the thermostat and that's the whole point.  If the relay is sticking in high speed mode, does this explain the low level of hot air coming out of the vents? 

Also, someone else suggested it may be a sequencer issue.  Is this one in the same, something else entirely, and does it have any merit?

...Back in my tiny attic built for a skinny man for me...

Thanks

[applianceman18007260692]

Is this electric heat or gas? and do you have pictures?

[mbonfa1]

It's electric.  What would you like pictures of and I can get them?

Thanks.

[applianceman18007260692]

You have fan

you have a little heat

so i would say

maybe one of your heater elements

needs replacement.

[mbonfa1]

Sorry for the delayed response, but I live in Louisiana and sometimes it is more important than others to have a functional heater. 

Turns out you were right.  One of my two heater elements is blown.  I can't find a replacement for that.  I'll attach a picture.

The other problem wasn't the relay, but I suspect it is the sequencer.  I have a picture for that too.  I can't find the correct replacement part.  The problem is the second level of the sequencer.  One side has two prongs and the other just has one.  The only ones I can find have one on each side.  My part number on the base of the sequencer is 15sh4 309706. 

Any idea on where I can find this part?  If not, is there a way to circumvent the one/two prong problem?  And finally, someone with more knowledge than me, do you think this really is the problem or am I in over my head?

Thanks for any help you can provide.

[mbonfa1]

Here is the heater element...

[mbonfa1]

And here is my awesome paint diagram with text and arrows.

[mbonfa1]

And while I am going nuts...  This is someone else's picture that I found.  It looks exactly like mine, but is better than my pics...

[RegUS_PatOff]

 

40AO036330EH

from here it looks like it may be:

40AQ036330EH    :ooo: see RegUS_PatOff

40AQ036330EH 36,000 Btuh  w 10Kw Electric Heater

 

SEQUENCER malfunction will cause heater not to come on or never shut off - replace sequencer.

 

HN67QC005  Sequencer

 

Maybe this one ? 

"Air Handler/Electric Furance Models

40AQ ..."

Carrier part # HN67QC005

click on picture

I can't read the numbers on it ....

but there IS (2) terminals on the second level on the left

OR this one on eBay NewInBox BuyItNow $7 + $6.50 shipping

[RegUS_PatOff]

I couldn't find much about the Heater...

there are about (15) PDF files here about the 40AQ

I D/L all of them (total about 15 MB)

 

 

[mbonfa1]

That sequencer looks good.  I ordered it.  Digging through those files, I think the heater coil part number is:  40fs900141.  Is this correct?  And any ideas on where I would get it?

And you are right about the AQ part.  Once I took that panel off, I could read it better.  Sorry I didn't update.

Thanks for all the help.

[RegUS_PatOff]

I had already searched for that Heater part number .. no luck...

You may have to use some type of generic heater coil wire ...

I think each of (2) "strands" is 5000 watts

[mbonfa1]

Ewww...  Any link you may know of that I could read up on what that means?

Best 5 bucks ever!

[hvacdrd]

I found this restring kit that looks like it would work. Yours has 2 elements each 5KW

The original heater assembly is P/N 40aq901031 includes the sequencer relay & transformer.

[RegUS_PatOff]

[user=41302]mbonfa1[/user] wrote:

.... One of my two heater elements is blown....

I'd replace both of them.

[mbonfa1]

Is this the same thing?  And I should order two? 

http://cgi.ebay.com/NEW-DH500-RESTRING-KIT-FOR-ELECTRIC-FURNACES-5KW-5000W_W0QQitemZ260352984827QQihZ016QQcategoryZ42911QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Do you think this will come with instructions or is it easy enough without them?

Thanks

[RegUS_PatOff]

looks good, should be easy enough.

just remember, as mentioned in the listing

 

"The coil should be evenly stretched a minimum of 1-1/2 to 5 times the close wound length...."

[mbonfa1]

Son of a...

Yeah, so I'm $80 and hours of learning into this project and still can't get the heater to shut off.  I have changed out the relay switch and sequencer (twice).

Any ideas?  Could it be the actual thermostat?  I hear it click, but it doesn't shut off...

Don't really want to give up at this point, but should I?

[RegUS_PatOff]

[user=41302]mbonfa1[/user] wrote:

... Also, when it finally hits the correct temp, it won't turn off by itself.  The A/C shuts off properly and cools properly...

What doesn't shut OFF, just the FAN, or the FAN & HEAT (the Contactor could be sticking ?)

How do you turn it OFF ?

Turn the Power OFF ?

If you turn the Power back on right away, does it start heating again by itself ?

[mbonfa1]

The fan and the heat keep running.  I turn it off by switching the thermostat off.  And it takes 30 seconds to shut off when I do turn it off and it comes back on within 5 seconds when I turn it back on (regardless of temp).

 

[RegUS_PatOff]

Sounds like a bad Thermostat, which model are you using ?

 

[mbonfa1]

It's a ritetemp 8022c.  I am going to look into this tonight.  I switched out the 1980's version thermostat probably about 9 months ago for this digital one.  I honestly don't remember if this problem existed before I did it.  The heater has been broken since before I switched it out.