Circuit breaker won’t reset on Heatmor CSS200

[HavinFun]

Hello,
Circuit breaker gradually began to trip a week ago, getting shorter intervals to reset until it won’t reset at all. Circuit breaker is good, indoor power switch is good. Disconnected power to other stove circuits at the stove junction box, circuit breaker does not trip. This leads me to believe tripping issue is at the stove.
Disconnected power to front light and fan switch, still tripped. Disconnected power to outlet box in back, still tripped. Disconnected pier to low limit aquastat, still tripped. Disconnected power to high limit aquastat, did not trip! Bought new HL aquastat, hooked wires up, tripped again ($160, ouch!). Disconnected wiring in junction box in back, ran separate wires from power to HL aquastat, still tripped. I’m out of ideas at this point. Could be bad new Resideo L6006A1245, but highly doubt it. Any ideas? Thanks for your help.
Best regards.
John

 

[begreen]

The issue could be with the wiring going to the unit. Each leg should be tested for leakage to ground.
Note that when circuit breakers trip a lot, they often will start tripping at lower than rated loads.

 

[HavinFun]

Hi Begreen,
Thanks for the reply. Sounds like a good move to test the underground wires . Will let you know what I find.

 

[HavinFun]

Hello,
Still tripped. I ran a heavy duty power cord to unit from working GFCI outlet in the garage. Wired into wires that came from the underground. Tripped when I plugged it in. Tried several times.
Red wire to high limit aquastat from 3-wire is not connected to anything in the garage, just wire-nutted off. Ran as it should before, so I assume that red wire is for a 220V hookup.
Any other possibilities it could be? Thanks.

 

[begreen]

Is there a schematic for the boiler wiring?

 

[HavinFun]

Yes.

 

[HavinFun]

My furnace does not have the door open switch, so you can ignore that. Wire colors are correct with what is installed on boiler. Left side of schematic is fan blower on bottom, light on top. With switch up, fan comes on when boiler water falls below 160 on signal from low limit aquastat on left. With switch down, light comes on and disables fan so no fireball when door open. Right side below junction box is outlet box that pump plugs into. Although red wire is hooked up on my HL aquastat on left, it is wire nutted in box in garage, so only black and brown wires active.
Much thanks for your help.
Best regards.
John

 

[brenndatomu]

My best guess would be mouse chewed wires, or possibly melted (both?)

 

[begreen]

Agreed brenndatomu, the question is which and where. The combustion fan wiring does see some heat. That should be checked.

It sounds like the breaker tripping with the unit cold. Is that correct?

Is there a safety switch at the boiler shed that disconnects the unit for servicing? If so, with it open (boiler disconnected), does the breaker trip or stay on?

I wish Heatmor didn't call this a furnace. It's a boiler, furnaces are for warm air.

 

[brenndatomu]

I wish Heatmor didn't call this a furnace. It's a boiler, furnaces are for warm air

Right?!
Well, its not really a "boiler" either...wood fired hydronic heater...but boiler is closer, and more common.

 

[HavinFun]

Hi Gents,
Thanks for the input. I was thinking a mouse might have chewed the wires, but the wires are in metal sheathed spiral conduit (name escapes me). The boiler has not been lit for a week, so it is tripping both hot and cold.
I thought it might have been the fan or light, but with wiring disconnected to both it still trips. Next outlet and low limit aquastat we’re disconnected and still tripped. Only when high limit was disconnected did it stop tripping.
Today when I ran a power cord from the garage it tripped the GFCI outlet it was connected to. What do you make of it not tripping when HL aquastat is disconnected.
Thank you bc again for your time.
Best regards
John
PS I bought the house five years ago and this is the first year I’ve run it due to high oil heating costs. I had to remove sides, strip out all old and mouse chewed insulation, Cleaned whole thing, re-insulated, and put into service.

 

[brenndatomu]

but the wires are in metal sheathed spiral conduit (name escapes me)

We have always called it armorflex...but I think that is actually just a popular brand name.
So is the armorflex under the insulation? (next to the 180* water)

Today when I ran a power cord from the garage it tripped the GFCI outlet it was connected to

Does this power the circ pump(s) too? Pumps can/will trip a GFCI outlet when there is nothing really wrong with them...but that still doesn't explain popping the breaker.
So the pump just plugs in? And you tried it with the pump unhooked?
So you said it is ok when the HLS is unhooked, right? HLS is allowing power to go to the combustion blower (as its called for) so have you left the HLS but unhooked the blower? Also, the manual shows a red wire going back to the building to start an alarm, or "heat dump pump" in the event of an overheat...is this hooked up?

 

[brenndatomu]

Also, I don't see it in the wiring diagram, but these things usually have some sort of actuator that opens the combustion air access up when there is a call for heat...and they are known to cause trouble, some brands/models more than others...what does this machine have, and has it been ruled out?

 

[HavinFun]

Hi Bren,
Just remembered that I did not disconnect ground wire from front light/fan switch. I’m thinking if a wire going to there through conduit was bare it could ground against metal sheath and send current to ground wire and maybe trip breaker. The pump is new but has been disconnected during this affair.
Armor flex was outside of insulation to light and fan switch. But, I was running it at 200 degrees on HL aquastat, which is how it was set when I started to get it going, so I left it there not knowing any better. I was told that was too high, so turned it down to 180.I do remember the water boiled at one point too. I closed the door to kill the fire.
One thing - I ran the boiler with an extension cord to the pump, and left the door open to get air to fire since nothing was working. I also burned a piece of oil soaked cardboard in the firebox. Some flames came out the front of the firebox, maybe I melted a wire somewhere? The more I read what I wrote makes me think it’s been overheated. If that’s the case I’ll take the dumbass award if there’s one.
No, the alarm is not connected. I did not know there was supposed to be one. That explains why the red wire is capped in the box in the garage and not connected to anything. Obviously there should be one, right? Can you suggest one? Thanks. Live and learn.

 

[brenndatomu]

Hi Bren,
Just remembered that I did not disconnect ground wire from front light/fan switch. I’m thinking if a wire going to there through conduit was bare it could ground against metal sheath and send current to ground wire and maybe trip breaker. The pump is new but has been disconnected during this affair.

Generally the conduit is grounded by being mounted to metal boxes that are grounded...some armorflex has a wire wound into it and can be used as a ground by code.

One thing - I ran the boiler with an extension cord to the pump, and left the door open to get air to fire since nothing was working. I also burned a piece of oil soaked cardboard in the firebox. Some flames came out the front of the firebox, maybe I melted a wire somewhere? The more I read what I wrote makes me think it’s been overheated

That's what I was wondering...an overheat or two may have very well melted something a lil...can you unhook the wires one by one on both ends and see if they have continuity to ground? Or how hard to just pull out the wires and just replace? Would only have to do the wire in the conduit in hidden/hot places...seems like it may be simple? I dunno, never touched a Heatmor.

No, the alarm is not connected. I did not know there was supposed to be one. That explains why the red wire is capped in the box in the garage and not connected to anything. Obviously there should be one, right?

Just reading the manual...they say there should be an alarm, or hooked to a "heat dump pump"...could be as simple as an old radiator and old furnace blower out in the garage or basement...that's how many people do DIY garage heaters anyways

 

[HavinFun]

Hi Bren,
Thank you for sticking with me on this. My plan is to run some temporary wires outside of the boiler just to see if I can get it to run properly. Your suggestion of a melted wire is likely the case. Since I’ve been looking at this for awhile and have the schematic I think I know where all the wires are going. When I do get it running properly I’ll then work on pulling new wire through the Armorflex in the bad spot(s).
I would like to set-up a heater for the garage and thought about using a radiator and a box fan as you have suggested. I can run the PEX and all, but not sure if the BTUs can handle the garage and house. That will be a topic for another post. Thank you again.
Best regards.
John

 

[HavinFun]

The boiler is working again. I rewired the boiler to bypass the wiring in the armored metal cable that goes to the front to control the fan and light. Since it’s working that is where the short must be. I probably caused myself all this bs by not being fully familiar with how to operate the boiler. I ran the wiring outside the boiler along the side and to the front. I did not use the front junction box but instead wired the fan switch down low near the fan. I don’t have the front light but ran a drop light to the front so have light. Next summer I’ll work on pulling new wires through the conduit and set-up as normal.
Thanks again Begreen and Bren for lending a hand with your advice.
Best regards.
John

 

[brenndatomu]

Good deal...make sure you use high temp rated wire...like XHHW

 

[big_z]

Hi Gents,
Thanks for the input. I was thinking a mouse might have chewed the wires, but the wires are in metal sheathed spiral conduit (name escapes me). The boiler has not been lit for a week, so it is tripping both hot and cold.
I thought it might have been the fan or light, but with wiring disconnected to both it still trips. Next outlet and low limit aquastat we’re disconnected and still tripped. Only when high limit was disconnected did it stop tripping.
Today when I ran a power cord from the garage it tripped the GFCI outlet it was connected to. What do you make of it not tripping when HL aquastat is disconnected.
Thank you bc again for your time.
Best regards
John
PS I bought the house five years ago and this is the first year I’ve run it due to high oil heating costs. I had to remove sides, strip out all old and mouse chewed insulation, Cleaned whole thing, re-insulated, and put into service.

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Wow! Great pics. I have a Heatmor 200 and I think I'll put this task on the todo list for next summer. Did you fill that top cavity with all insulation?

 

[HavinFun]

Yes. Completely filled with rock wool. Easy to work with it and can cut shapes for good contour when needed. Good luck with your project.