Oil furnace lockout, water heater, heat pump and power venter


  #1  
Old 12-16-09, 05:25 PM
D
Member
Thread Starter
Join Date: Dec 2009
Location: quebec, canada
Posts: 9
Received 0 Votes on 0 Posts
Oil furnace lockout, water heater, heat pump and power venter

My furnace is going into lockout very frequently and it took me quite some time to attempt to pin down the sequence of events provoking this condition. Hopefully, my minimal skills in HVAC and its relevant terminology will not prove to be too much of a hindrance.

I initially believed the problem to be intermittent and related to the heat pumpís defrost mode but I now think the root cause is elsewhere - possibly an incorrectly set jumper/configuration setting, a relay or a time delay switch that is not operating correctly.

I am able to recreate the lockout condition reliably but I could sure use a helping hand in drilling down to the root cause and/or remedy.

System configuration information:

Heat Pump: Carrier 38YXA (3 ton) split system
single speed

Furnace: Carrier "Lowboy" 58CLA - 120 series (oil)
Beckett AFG burner
Honeywell Interrupted Electronic Oil Primary: R7184 B
( note: control board in furnace replaced after a major meltdown last spring)

Water Heater: Brock IB-32R (oil)
Beckett AFG burner
Honeywell IEOP : R8184

Side wall Power vent: UTC Canada Corp. Model SMH and also branded on the junction box as Brock D-B-1

Thermostat: Carrier Thermidistat - TstatCCPRH01-B (recently replaced due to a internal humidy sensing failure.

Dual fuel control relay?: BP Porter (The Heat Pump Made Easy)


Dual energy (Oil furnance/ heat pump) and a single power side wall vent for both, the oil furnace and the oil water heater with the priority going to the water heater. In other words, if the water heater is in operation, the furnace should not operate despite a call for heat either due to a defrost cycle from the heat pump nor a call for heat from the thermostat.


Since the problem revealed itself intermittently and very rarely in recent months & appeared to coincide with defrost cycling, I initially thought that the problem was with this function. However, now that there are frequent calls for the furnace to engage, the lockout state on the furnace happens multiple times a day. A simple push of the reset button and the furnace burner restarts without issue.

Here is one and I suppose the most consistent scenario:

While the furnace is in operation, I simply have the water heater startup ( by increasing the temperature setting). The furnace then shuts down as it ought to and the primary LED blinks in recycle mode for a bit of time. Despite the fact that the water heater is in operation, the call for heat to the furnace appears to continue and after three failed attempts, the primary then fails and goes into lockout. Providing the water heater is not in operation, pressing the reset starts the furnace (except for what seems to be a delay before ignition of about 10 seconds). To this I would add that if the water heater shuts down while the LED is still flashing in recycle mode and there is still a call for heat, the furnace usually recovers gracefully.

The main board of the furnace was replaced last spring following a complete meltdown (burnt to a crisp including the attached wiring). I replaced the thermostat recently as it was failing on the humidity function (internal error 5).

My inclination is to believe that a jumper or setting on the furnace's main board may not have been correctly set when it was replaced last spring by the contractor or that there is a failed relay common to the power vent that is not stopping the request for heat to reach the primary.

Your help and insights would be most appreciated.
 
  #2  
Old 12-16-09, 07:29 PM
Grady's Avatar
Forum Topic Moderator
Join Date: Jan 2005
Location: Delaware, The First State
Posts: 14,401
Received 37 Votes on 35 Posts
Furnace control board

Not being familiar with that furnace I suspect the control board is a Honeywell ST9103. Please check the board for a manufacturer's name & number. With that information, maybe I can help.
 
  #3  
Old 12-17-09, 05:10 AM
D
Member
Thread Starter
Join Date: Dec 2009
Location: quebec, canada
Posts: 9
Received 0 Votes on 0 Posts
Hello Grady,

The board does not appear to have Honeywell branding although I did note on the schematic diagram the number ST9103. The number on the board is R99G004 however, I believe that the original part was R99G002.

I have a schematic I could scan for you if need be.

Thank you for replying.
 
  #4  
Old 12-17-09, 08:46 PM
Grady's Avatar
Forum Topic Moderator
Join Date: Jan 2005
Location: Delaware, The First State
Posts: 14,401
Received 37 Votes on 35 Posts
Schematic

A picture of the schematic would indeed be helpful.
 
  #5  
Old 12-18-09, 08:34 AM
D
Member
Thread Starter
Join Date: Dec 2009
Location: quebec, canada
Posts: 9
Received 0 Votes on 0 Posts
unable to upload files / images from PC

Originally Posted by Grady View Post
A picture of the schematic would indeed be helpful.
Grady,

I am sorry, but rather than send you a reply, it seems that I created a new thread instead. Sorry for the duplication. It appears with the title reply re schematic which should be deleted I guess.

It would appear that I cannot upload images from my PC. In the forum options, attachments are disallowed.
 
  #6  
Old 12-19-09, 11:51 AM
D
Member
Thread Starter
Join Date: Dec 2009
Location: quebec, canada
Posts: 9
Received 0 Votes on 0 Posts
resolved

Grady,

After going through all the schematics, I started to have a much closer look at what the installation contractor had done and had to through in the towel.

They hadn't followed many norms, I found multiple poor connections ( both 24v and 120v), wiring was not at all what I expected as per the schematics, multiple looped circuits going basically around in circles and bridged through multiple useless relays ( I am now minus 4).

As the temperatures had dipped below freezing a few days, I was unable to take the time to handle the issue on my own and called in another firm to resolve the problems.

They concurred with many of my findings and as the wiring was such a mess, I essentially had to get the entire system stripped down and re-wired. After 20 hours, things are now to code, fully functional, all components tested and balanced including the lack of a correct draft for the appliances.

I want to thank you for having taken the time to try to assist me and kudos to all of you helping those of us in need.
 
  #7  
Old 12-19-09, 12:11 PM
Grady's Avatar
Forum Topic Moderator
Join Date: Jan 2005
Location: Delaware, The First State
Posts: 14,401
Received 37 Votes on 35 Posts
Glad all is well

I'm certainly glad the other firm was able to get things wired correctly & you are now up & running. Just for future reference, if you could post the schematics on photobucket or similar site & provide a link here, it would certainly be appreciated. With that information, maybe we can be more sucessful it trying to help someone else in a similar situation.

My self & dozens (hundreds?) of others are here because we enjoy helping. Thank you for your kind remarks.
 
  #8  
Old 12-19-09, 12:18 PM
D
Member
Thread Starter
Join Date: Dec 2009
Location: quebec, canada
Posts: 9
Received 0 Votes on 0 Posts
Grady, I will endeavour to do so. Thanks again.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: