Honeywell Intermittent Pilot Retrofit---Help!

Reply

  #1  
Old 12-03-07, 03:48 PM
Rickochet's Avatar
Member
Thread Starter
Join Date: Nov 2007
Location: Indiana
Posts: 16
Honeywell Intermittent Pilot Retrofit---Help!

I just converted my old standing pilot Sterling Unit heater to the Honeywell Y8610U and I have a few questions. I thought I was receiving reliable info before I started this project, but..... Well after the installation, I got the burner to light, but it cycles on and off repeatedly until the room temp rises to the desired thermostat temp setting. The cycling is due to the Thermodisc switch near the heat exchanger sensing the proper temp to allow the fan to operate. However, when the Thermodisc cools down it removes power to the fan circuit.

The Honeywell instructions indicate that 24 volts must go to the module with a "limit controller" inline. Is the limit controller the other thermodisc that is in the junction box with the 24v transformer? I have not tried any combinations using that set up and before I do, does anyone have a suggested wiring diagram for this particular setup? Thanks in advance for the advice!
 
Sponsored Links
  #2  
Old 12-03-07, 05:00 PM
Banned. Rule And/Or Policy Violation
Join Date: May 2007
Location: Wisconsin
Posts: 8,629
This short cycling condition you have when the unit is cold: Is it the blower fan that sends air out the registers that is kicking off on you? If so, are the burners going while this happens, while the room is still calling for heat? If so, what can happen is if the room is too cold, the cold return air brings down the temperature inside the furnace (while the burner is going) to a temperature below that of the shut off temp of the fan's thermodisc off switch. But this problem should not be happening in a house say that is already approximately 50 degrees or maybe somewhat less.

If you have the problem with the blower going off, while the fire is going, what kind of temperature is in the house when your problem is going on?

Regarding the limit: You want the limit wiring to be in line with the gas valve wiring so that when the furnace gets too hot the fire shuts down. The thermodisc limit switch "opens" when this happens, and then when the furnace is overheated the blower keeps running, and when the furnace cools down enough, the limit switch "closes" and then the fire can come back on again, if there is still the call for heat.

Limit switches are located above the burner area.
 
  #3  
Old 12-03-07, 06:13 PM
Member
Join Date: Aug 2007
Posts: 2,021
I'm a little confused. Are you thinking that you mistakenly wired the 24v input to the module from the fan thermoodisc? If that's true, then the burners would never fire because the thermodisc switch would be open on startup. The second thermodisc you mentioned, what is it's actual physical location? You made it sound like it's in the junction box but it doesn't belong there. You'll need to check and see if the input terminal [TH-W] to the module is hot or dead when the burners shut off. That terminal should be hot all the time whenever the thermostat is calling for heat. The exception would be if the limit switch opens. [check for 24v from TH-W to 24V GND] Maybe the burners are cycling on/off on the limit control because the fan thermodisc isn't working properly? Let us know what you find. Thanks.
 
  #4  
Old 12-03-07, 07:56 PM
Member
Join Date: Nov 2007
Posts: 36
take out the thermodisc and put in a high limit switch with a fan time delay. cant even get thermodisc's for most models anymore anyways....for MOST not all.

and to fully understand what your saying draw a picture or take a picture with diagram of what your talking about. i'm guessing your unit has either A) a fan/limit thermodisc (cant get anymore for most units) or B) a fan limit and a high limit switch . to know for sure a diagram would clear things up in a hurry as well as push you in the right direction
 
  #5  
Old 12-04-07, 06:27 AM
Rickochet's Avatar
Member
Thread Starter
Join Date: Nov 2007
Location: Indiana
Posts: 16
Originally Posted by LaBait View Post
take out the thermodisc and put in a high limit switch with a fan time delay. cant even get thermodisc's for most models anymore anyways....for MOST not all.

and to fully understand what your saying draw a picture or take a picture with diagram of what your talking about. i'm guessing your unit has either A) a fan/limit thermodisc (cant get anymore for most units) or B) a fan limit and a high limit switch . to know for sure a diagram would clear things up in a hurry as well as push you in the right direction
Looking at the Grainger site, what control would you recommend? I was looking at the 2E232 .
 
  #6  
Old 12-04-07, 11:33 AM
Rickochet's Avatar
Member
Thread Starter
Join Date: Nov 2007
Location: Indiana
Posts: 16
Honeywell L4064B mounting

I bought a Honeywell fan control and need help deciding where to mount it on the furnace. The furnace is a Sterling 100,000 btu LP hanging unit. I assume that it mounts through the sidewall and into the plenum without touching anything. Is this correct?
 
  #7  
Old 12-04-07, 01:31 PM
Member
Join Date: Aug 2007
Posts: 2,021
I don't believe I would satrt drilling holes. If you drill into the heat exchanger, you will ruin it. White Rodgers makes a line of aftermarket surface mount thermodisc type controls.
www.white-rodgers.com Are there any numbers on the existing control? Take a look at Grainger # 2E364. The fan control is a time delay relay type. For the fan it looks like they are using a sequencer similar to those used for electric heat strips.
 
  #8  
Old 12-04-07, 09:31 PM
Member
Join Date: Nov 2007
Posts: 36
Originally Posted by Rickochet View Post
Looking at the Grainger site, what control would you recommend? I was looking at the 2E232 .
before i can recommend anything i need to know if its a fan/high limit thermodisc
has 2 heads instead of 1
 
  #9  
Old 12-04-07, 09:35 PM
Member
Join Date: Nov 2007
Posts: 36
Ok i took a look at your picture, is that what your running or are you running an actual product called a "thermodisc" ? i'll see if i can find a picture to assist better
 
  #10  
Old 12-04-07, 09:42 PM
Member
Join Date: Nov 2007
Posts: 36
http://www.tod.com/loadMedia.asp?Met...&ReturnPage=14

Looks something like that but with 4 prongs and 2 heads. sometimes cardboard like that one or plastic
 
  #11  
Old 12-09-07, 10:39 AM
Rickochet's Avatar
Member
Thread Starter
Join Date: Nov 2007
Location: Indiana
Posts: 16
Thanks for the input. I decided to go with an adjustable thermal switch. Works like a charm, simple and cheap too!
 
Reply

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


Thread Tools
Search this Thread
Display Modes