Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > HVAC

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 04-22-2012, 11:01 AM   #1
Newbie
 
itlldue's Avatar
 
Join Date: Apr 2012
Posts: 8
Share |
Default

Day & Night Issues


Newbie here, located in central CA. I buy and sell used and surplus for a living, and try to be a DIY guy for the most part. We started having issues with our 20 year old D & N model 376CAV, and came across this forum in search of answers. Hope you can point me in the right direction.

The heater (propane) started operating erratically this winter, cycling on and off at odd times. Replaced the thermostat with no improvement. I've had issues with the gas pressure switch before, but it tests OK. A little snooping started pointing to the lockout timer. I removed it, opened it up, gave it a good bath with contact cleaner (including the relay). That seemed to help for a bit, then it repeated the problem. It started to warm up outside, so I decided to postpone buying a new lockout until I could find a better price.

Yesterday, it got hot enough for the wife to use the air conditioner, and it does the same thing. I was under the impression that the lockout timer only controlled the heater, but now I'm not sure. Does it also control the AC, or do I need to look somewhere else? Today I plan to open it up and clean all of the electrical plugs.

Any other ideas? Thanks in advance for any help.

itlldue is offline   Reply With Quote
Old 04-22-2012, 11:31 AM   #2
Member
 
biggles's Avatar
 
Join Date: Jan 2008
Location: Long Island
Posts: 3,600
Default

Day & Night Issues


is the lock out timer in the furnace or the condenser.the timer is more for the restart of the condenser so the freon pressure can somewhat equalize between cycles like a window unit or refrig.the unit out side i 208/230 single phase and need it thru the time delay relay ot from a stat configuation setting ...to check the cooling pull the stat off the subbase....jump R to G and Y for a cooling supply fan run....lets here back on what happens....i'm telling you to jump the unit there to see if it runs then it might be the stat or the actual condenser with freon issue....or controll problem...

biggles is offline   Reply With Quote
Old 04-22-2012, 12:33 PM   #3
Newbie
 
itlldue's Avatar
 
Join Date: Apr 2012
Posts: 8
Default

Day & Night Issues


The lockout (H990-141-1) is in the furnace. And, as stated above, I am experiencing the same issues with heat or AC.
itlldue is offline   Reply With Quote
Old 04-22-2012, 05:12 PM   #4
Newbie
 
Join Date: Apr 2012
Location: New York
Posts: 8
Default

Day & Night Issues


Is it just the fan cycling on and off? You probably have known and are trying to buy some time with your old unit, but 20 yrs for your system is about at the end of its life cycle. You should consider saving your money on repair efforts and get some free estimates for replacement options.
Edward12 is offline   Reply With Quote
Old 04-22-2012, 08:04 PM   #5
Newbie
 
itlldue's Avatar
 
Join Date: Apr 2012
Posts: 8
Default

Day & Night Issues


Quote:
Originally Posted by Edward12 View Post
Is it just the fan cycling on and off? You probably have known and are trying to buy some time with your old unit, but 20 yrs for your system is about at the end of its life cycle. You should consider saving your money on repair efforts and get some free estimates for replacement options.
My house is on 7 acres in an industrial zone, and is in dire needs of repair. It will be worth more money as an office in the future. It served it's purpose as a home and place to have my business next door since 1986. The second of my two children is a junior in college, and as soon as she graduates and settles somewhere, we plan on selling the place and moving to the coast.

The company who installed the unit is still in business. I'll call them tomorrow and have them take a look. My electrical engineer son and I took a look this afternoon, and one of the relays on the PCB is sparking pretty bad upon activation, so I suspect the problem lies therein. If a $1000 or less bill will buy me two years, then I'll do it. If it looks like more, then a new unit is in order.

PS - No, the fan works fine. The AC unit won't even start today. And, no, it's not blowing fuses or popping the circuit breaker. It just isn't getting the command to start.
itlldue is offline   Reply With Quote
Old 04-22-2012, 09:57 PM   #6
I'm Your Huckleberry
 
Join Date: Mar 2011
Posts: 5,540
Default

Day & Night Issues


Quote:
Originally Posted by itlldue View Post
My house is on 7 acres in an industrial zone, and is in dire needs of repair. It will be worth more money as an office in the future. It served it's purpose as a home and place to have my business next door since 1986. The second of my two children is a junior in college, and as soon as she graduates and settles somewhere, we plan on selling the place and moving to the coast.

The company who installed the unit is still in business. I'll call them tomorrow and have them take a look. My electrical engineer son and I took a look this afternoon, and one of the relays on the PCB is sparking pretty bad upon activation, so I suspect the problem lies therein. If a $1000 or less bill will buy me two years, then I'll do it. If it looks like more, then a new unit is in order.

PS - No, the fan works fine. The AC unit won't even start today. And, no, it's not blowing fuses or popping the circuit breaker. It just isn't getting the command to start.
Have you tried bypassing the thermostat by jumping the R to the Y terminal on the control board? You leave the stat in the off position when doing this.
__________________
Thanks.
Doc Holliday is offline   Reply With Quote
Old 04-23-2012, 10:00 AM   #7
Newbie
 
itlldue's Avatar
 
Join Date: Apr 2012
Posts: 8
Default

Day & Night Issues


Quote:
Originally Posted by Doc Holliday View Post
Have you tried bypassing the thermostat by jumping the R to the Y terminal on the control board? You leave the stat in the off position when doing this.
As I said in the original post, I have replaced the thermostat (twice).
itlldue is offline   Reply With Quote
Old 04-23-2012, 10:14 AM   #8
I'm Your Huckleberry
 
Join Date: Mar 2011
Posts: 5,540
Default

Day & Night Issues


And as I've said in my original post, have you tried BYPASSING the thermostat, regarldess of if it's new, connected or not, by JUMPING THE TERMINALS ON THE CONTROL BOARD. THE CONTROL BOARD IS WHAT RUNS THE FURNACE, NOT THE STAT. THE STAT IS A SIMPLE SWITCH, NOTHING MORE.

More than likely you'll have the same results, though. It's just a technical way of making certain the stat is not the issue, taking it completely off line and you can do that and still run a furnace.

Have you tried resetting all power to the furnace, flipping the breaker off and then back on?
__________________
Thanks.
Doc Holliday is offline   Reply With Quote
Old 04-23-2012, 12:35 PM   #9
Newbie
 
itlldue's Avatar
 
Join Date: Apr 2012
Posts: 8
Default

Day & Night Issues


Quote:
Originally Posted by Doc Holliday View Post

Have you tried resetting all power to the furnace, flipping the breaker off and then back on?
Yep, several times.

When turning it on and off, there is some serious arcing in one of the two relays in the control box.

I called a tech.
itlldue is offline   Reply With Quote
Old 04-23-2012, 02:00 PM   #10
I'm Your Huckleberry
 
Join Date: Mar 2011
Posts: 5,540
Default

Day & Night Issues


Let us know what he finds, please.
__________________
Thanks.
Doc Holliday is offline   Reply With Quote
Old 04-23-2012, 07:56 PM   #11
Newbie
 
itlldue's Avatar
 
Join Date: Apr 2012
Posts: 8
Default

Day & Night Issues


Well, we don't really know now. When he got here, he flipped the unit on and it worked fine. A few tests didn't reveal much. An amp probe on the AC unit didn't show anything. He noticed that the start relay on the compressor unit was OEM, and suggested I change it while he was here. I agreed.

We went back inside to test the heating circuit, which also worked fine, so it might be a sporadic problem with the lockout relay. I may just buy another and swap it out myself before winter.

While testing, I was playing with the NEW thermostat, and it stuttered again. He looked at it and told me in no uncertain terms to dispose of it and buy a better one. He came into my office, we looked them up on the internet, and he showed me which one to get. I ordered it right then.

Seems he's the grandson of an old customer of mine, so we BS'd awhile. I gave him a new cheapo VOM (I have about 350 of them NIB from a government sale), a nice set of test leads, a check for services rendered, and sent him on his way.

I'll install the new thermostat when it gets here, and we'll see if it helps the heating problem also.
itlldue is offline   Reply With Quote
Old 04-23-2012, 08:17 PM   #12
I'm Your Huckleberry
 
Join Date: Mar 2011
Posts: 5,540
Default

Day & Night Issues


Someone very, very clever, of an atmospheric genious already posted on this thread suggesting to bypass the stat altogether.
__________________
Thanks.
Doc Holliday is offline   Reply With Quote
Old 04-23-2012, 08:31 PM   #13
Newbie
 
Join Date: Apr 2012
Location: New York
Posts: 8
Default

Day & Night Issues


Edward12 is offline   Reply With Quote
Old 04-25-2012, 08:00 PM   #14
Newbie
 
itlldue's Avatar
 
Join Date: Apr 2012
Posts: 8
Default

Day & Night Issues


Quote:
Originally Posted by Doc Holliday View Post
Someone very, very clever, of an atmospheric genious already posted on this thread suggesting to bypass the stat altogether.
I temporarily concede.

Having been through 3 thermostats, I pretty much figured it was eliminated as the problem. However, I am still not convinced that the issue has been resolved (we haven't used it yet), or that the thermostat was the culprit. The lights used to dim slightly when the compressor came on. Now, with the new relay, they don't. Time will tell. I'll keep you posted.

itlldue is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
just installed water softner and having hot water issues. acoers Plumbing 16 02-28-2012 03:44 PM
furnace blower won't turn on at night. mariamav3 HVAC 9 02-16-2012 07:54 PM
Childproof Night Light user1007 Electrical 2 02-10-2012 11:23 AM
outside unit running all night wetbar HVAC 6 11-22-2011 06:41 AM
Electric Run, Voltage Drop Issues. Eventual upgrade of system this year. lawnphysics Electrical 4 04-06-2011 06:24 PM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.