Beacon Morris BRT75 Troubleshooting

[awehlage]

Hello everyone, first post here and looking for some help.

Just picked up a used Beacon Morris BRT75 that is about 8 years old. I currently have 2 LED flashes on the control board. There are 4 possibilities according to the manual that could be causing this code. I called tech support and they suggested to replace the gas valve. Did that and still not working. According to other threads it could be the control board. Control boards are at least $200 for this model, however, in my search attempt I noticed a lot of heaters use similar looking boards just different part numbers.

Is there a compatibility list for which control boards are a direct swap so I can spend less money just in case it is not the control board? My control board reads: 11J28-06881 1097-507

Thanks in advance!!
-Andrew

 

[tinker rick]

Check out H-MAC for parts for your heater.

 

[awehlage]

Thanks tinker rick.

I have been to that website and the control board is $205.

As I search the internet control boards like Lennox 52M46 and Honeywell 1097-83-503A 1097-503-I look identical and can get them significantly cheaper. Are all boards the same but rebranded and given different model numbers for the different brands of heaters/furnaces?

 

[Showkey]

Unfortunately it’s Time to re-evaluate the purchase ..........brand new 80k unit is $400-480 so parts purchase soon make little or new economic sense. Especially if you inspect the heat exchanger and exhaust area for rust.

Also confirm which parts are bad. Flame sensor, ignition, blown fuse, power issue, powervent sensor, powervent fan and temp sensors are far more common problems than gas valve and board. No substitute for troubleshooting. It is surprising tech support talked to you........most responses are we only talk to certified HVAC techs ( no DIY).

My Lennox 60k ( rebadged unit) burnt the board. Obvious failure, opted to junk the unit after inspection and looking at parts prices. My board was $85 plus shipping. My exhaust area was very rusty. Power vent fan was also pretty rusty. Purchased a 45k unit at Menards for $350.

Mr. Heater® Big Maxx 80,000 BTU Garage Heater $418.26

If you continue troubleshooting more info is needed........doe the power bet fan run? , does it ever fire, does it fire and shut down after 3-5 seconds ? Does the ignition spark or glow ?

 

[Done That]

Thanks tinker rick.

I have been to that website and the control board is $205.

As I search the internet control boards like Lennox 52M46 and Honeywell 1097-83-503A 1097-503-I look identical and can get them significantly cheaper. Are all boards the same but rebranded and given different model numbers for the different brands of heaters/furnaces?

Not necessarily. Physically may appear the same as its a hardware platform, but the firmware can be quite different. You would have to verify things like igniter warm up time, prepurge, postpurge, trial for ignition, etc etc to be able to declare a match.

Not a good idea if you are a novice on gas ignition.

 

[awehlage]

If you continue troubleshooting more info is needed........doe the power bet fan run? , does it ever fire, does it fire and shut down after 3-5 seconds ? Does the ignition spark or glow ?

Here is my startup:

1. Provide power to the unit
2. Green LED immediately starts flashing 2x’s
3. Power vent fan kicks on after 10 seconds and continues to run until I disconnect power to the unit.

The unit never fires. There is no ignition spark or glow. I have looked at the troubleshooting guide and have found the following (answers in parentheses):

V. Power venter will not stop
1. Power venter improperly wired (Not that I can tell).
2. Main burner did not light on call for heat - Heater in lockout mode check flash code table for problem (2 flashes *see below)
3. Defective control board - No flash codes present along with no call for heat, replace control board (There are 2 flash codes but no call for heat)
4. Loss of pressure. Pressure switch not made. - Check venting for blockage. Check tubing for blockage or hole. Check spud for blockage. (All checks seem to be okay)

2 Flashes Troubleshooting
*In lockout from failed ignitions or flame loss.

1. Gas supply off or gas supply too low (Gas supply inlet is within range. Manifold pressure can not be checked as unit does not fire)​

2. Flame sense rod contaminated or loose wire. (Cleaned off flame sense rod with microfiber cloth and made sure wire was tightly attached)​

3. Gas valve switch is off or wires are not connected. (Gas valve switch is ON and wires are connected as follows - white wire is on the top and black wire is on the bottom)​

4. Broken or cracked porcelain on flame probe or spark igniter. (All seems to be solid and intact, no cracks present)​

What should I look for next?

 

[Showkey]

Did you test the pressure switch ??? Not being smart ***. “Seems ok” and tested good are to completely different answers.

I would confirm the pressure switch is actually working by testing .........the hoses ( remove and check pressure and flow), diaphragm (pressure test) and pressure switch ( voltage and or continuity check or both ).
It works something like this.. The start is inducer fan runs, pressure switch closes, ignition starts, gas flow starts, flame sensor confirms flame is present gas continues to flow. Each step has to checked, double checked and confirmed good.........so you don’t guess and spend BIG $$$.

 

[awehlage]

Did you test the pressure switch ??? Not being smart ***. “Seems ok” and tested good are to completely different answers.

I would confirm the pressure switch is actually working by testing .........the hoses ( remove and check pressure and flow), diaphragm (pressure test) and pressure switch ( voltage and or continuity check or both ).
It works something like this.. The start is inducer fan runs, pressure switch closes, ignition starts, gas flow starts, flame sensor confirms flame is present gas continues to flow. Each step has to checked, double checked and confirmed good.........so you don’t guess and spend BIG $$$.

No offense taken. I did remove and blow out the hose. There are no cracks and it is still flexible so I assume it is functional. I looked in the manual on how to test the pressure switch but did not find anything specific.

How do I pressure test the diaphragm? With a manometer? What should it read?

I assume the pressure switch should read 115V and have continuity to be functioning properly?

 

[Showkey]

Pressure switch diaphragm just needs to hold pressure or vacuum ........mouth test and watch the pressure switch continuity (power off) change.

Not 115 volts all the voltages on the gas valve and sensors are low volts.

 

[Michaeloangelo]

Mine acted like yours. I plugged a short piece of hose to the pressure switch and kept a vacuum to it by sucking on the hose. I then plunged the cord in while keeping a vacuume to the switch. Unit fired right up and kept running as long as I kept a vacuume on the switch.
So I now knew that my flue was stopped up. I unscrewed the induction fan and looked inside the exhaust port. It was almost completely plugged up with a muddobber nest. After cleaning it out it runs like new again.

 

[awehlage]

I just want to say that I have found the issue. It was the control board. I had a neighbor with the same model board and convinced him to let me use his to test. I plugged his control board into my unit and it fired right up. Had to adjust the manifold pressure a bit and that was it. Now I’m on the hunt for the lowest price I can find for a new one.

Thanks to everyone who gave input and helped me. I hope to contribute to the forum and be of assistance to other members as you have done for me.

Much appreciated,
-Andrew

 

[D45]

Whats the part number for the board?

 

[awehlage]

Whats the part number for the board?

The part number on the board is: 11J28-06881 1097-507. Lowest I’ve found for a new board is $189 including S&H.

 

[D45]

$145
http://www.northamericahvac.com/honeywell-lennox-control-board-1097-83-503a-1097-503-i/

It seems like there are numerous part number options

J28R06881

1097-83-503A 1097-503-I

 

[awehlage]

There are numerous part numbers for what looks like the same board (physically) but like another member mentioned above the firmware might be different. I know in my manual it lists two different control boards the "UT" and the "Honeywell". I am not sure that the board you linked is 100% correct unless someone can tell me they have used this and it is confirmed to work.

@D45 I appreciate your searching for me and thank you for taking the time to help me out!

 

[D45]

Do you have a local electronics repair business?

I once had a board bad on an old computer and it was fixed for $40, compared to $350 for a completely new board

Just an option to think about

 

[awehlage]

I could possibly take the old board somewhere, but I like to tackle things myself. I am going to try and find the schematics for the board and test for continuity and things like that across the relays. The heater won't fire so if I can find the circuit that controls ignition and replace the components myself that aren't programmable just drop in I think it might be a good little project. I also noticed that the Mr. Heater part #60105 (control board) is very similar in appearance with screw down terminals instead of spade terminals on the thermostat inputs. That board is ~$70. I don't need heat in the garage yet, still have to plumb the venting and tie up loose ends.

 

[Done That]

UT = United Technologies Electronic Controls or UTEC. This is part of Carrier. They make all the control boards for Carrier, and also sell to other OEM's. The two boards in your manual are functional equivalents, Beacon approved both to pit them against each other for cost, and to not be single sourced on a critical part.

More often than not when a board exhibits a "replace control" type fault it is due to corruption of the main micro, possibly from ESD (electrostatic discharge, lightening /power surge). Micro can't run it's pre-start checks without failure. Runs the inducer as a belts and suspenders safety purge.

That's a pretty basic single sided board so you can follow most of whats going on with the traces on the bottom side and the top side components.

Relay K1 by the 6-pin white plug conector is the gas valve relay
The other I/O in the 6-pin would be the limit(s), pressure switch
Relay K2 is the inducer relay
Relay(s) K3/K4 are for the main blower
U1/U2 in the middle of the pcb are the IC's/micros
FLAME 3/16" spade terminal is obviously the flame sense circuit

Not sure any of that's of help to you, but just in case.

Any obvious browning or darkening of the board on top or bottom??

 

[awehlage]

Maybe I will try a Honeywell board that is listed in the manual although looking at the parts lists it only lists 1 p/n for the control board. Still has me a bit skeptical. I see that there was a revision to the original board where they took out the relay that controls the cooling functions which is what got me thinking that there should be a cross reference list somewhere and compatibility between other brands since these boards are obviously used in whole house heating furnaces.

I don't have a way (right now) to program a microprocessor or obviously the code needed. I just wonder what the sequential order for startup is. What is the order for the checks and balances before the heater actually ignites. When I plugged the neighbors control board in the LED flashed a steady contant rate. When I plug the defective board in it would immediately have 2 LED flashes and then repeat.

The board is pretty clean with a few "dark" spots but nothing burnt from overheating or a high electrical current. The fuse wasn't blown but who's to say that wasn't replaced. No broken solder joints or components hanging there. I have a pretty in depth understanding for this type of stuff but I wouldn't say I'm an expert. I have made my own pcb's for custom LED/lighting projects for my vehicle and other things.

I started to trace out the circuits on the bottom of the board and identifying some of the components for a build list that I could easily place an order for and wouldn't cost too much for a trial and error process.

 

[Done That]

Something like this:
Micro self check
Turn on inducer
Verify pressure switch closes
Begin trial for ignition
Turn on spark output
Energize gas valve
Monitor flame sensor
Verify flame established within time period oem spec'd (typical 4 seconds)
If flame not sensed, turn off gas valve, keep inducer on to purge. Retry usually 3 times, if no flame ever established go to a hard or soft lockout
If flame established, run until thermostat demand is removed
During run, continuously monitor safeties like rollout and/or over temp limit
Turn on main blower after any heat on delay timer satisfied
Thermostat demand removed then turn off gas valve, turn off inducer
Continue to run main blower for blower off delay period if any
Go to standby state