Big Maxx heater trippin' - 4 flashes

[Vermont]

I've been battling my Big Maxx 50,000 ever since day 1 and the company has no solution. I've attached pix of my installation. It's a unique install but meets the clearances. Back 20", sides 8", top and bottom 4".

Here's the problem I keep having the rollout switch trip when it heats the room to about 60 degrees, runs for 1/2 hour. Panel has 4 blinking lights; so rollout or high level. I have to keep resetting the rollout after I make modifications. Also noted soot build up after running for total of 4 hrs total over lifetime. The unit has never ran properly.

Here are things I've tired:
- Crimped the top flame channel....still tripped
- Flames were very orange and not blue so tested pressure and company sent me new manifold and regulator. Now flames are mostly blue.....still tripped.
- Cleaned flue
- Had HVAC tech look everything over and test all components

The only thing I can think of, is that everyone else has the heater mounted in an open space, hanging from the ceiling. Could this possilby be causing the over heat?

Any ideas? The company covers parts but not the entire heater.

I'm ready to toss the heater to the curb and buy a Modine.

 

[The Cobbler]

I think you're on to something. it looks pretty cramped and certainly not a "normal install"

 

[brewchief]

Measure the air inlet and outlet temps when it's running, I would bet that it's pulling hot air bsck in and recirculating it and it simply overheats. Any brand heater will have problems if you stuff it in a hole like that.

Sent from my SM-G965U using Tapatalk

 

[LS6 Tommy]

Measure the air inlet and outlet temps when it's running, I would bet that it's pulling hot air bsck in and recirculating it and it simply overheats. Any brand heater will have problems if you stuff it in a hole like that.

Sent from my SM-G965U using Tapatalk

This. Even though your installation meets the clearance specs, it's not really design for those clearances to be a the minimum on all sides. You're recirculating heated air. I'd knock the sides off and maybe pitch the top up a little from back to front.

Tommy

 

[Vermont]

Great ideas. I'll make some modifications this week and see how things work. I'll get back to you guys. Thanks for your input!!

 

[ljhhontx]

If it were me I would back the orifices down to maybe 40,000 and see if that cleans it up, the soot means you're not getting enough air in to burn 50.000 btu, seems like your close though, a little tweak down will probably fix it without doing a lot of more costly mods.

 

[Vermont]

So I just decreased the regulator output. Put a fan behind the unit along with a thermometer. The temp read 64F the entire time. After 30 min's the rollout tripped. It's getting plenty of oxygen and the unit is cool. I even kept the side panel off. I'm stumped.

 

[LS6 Tommy]

What's the temperature rise? If it's within spec, the rollout safety is bad.

Tommy

 

[Jim greengo]

Are the flames actually rolling out?

 

[SALIV8]

I’d jump out the rollout and see what happens.

 

[Vermont]

Not sure what an actual 'roll out' looks like. There are 3 flames. The bottom flame is pure blue, second is blue with some yellow, and the top is blue and orange. The only lapping of the flame is from the middle flame to the top flame along the channel for lighting. I took out the burners last week and crimped the top channel to decrease the flame lapping. Hope this makes sense. The company sent me a new regulator because of lack of pressure and flames were all orange. Noticeable difference with new part.

I'm going to jump the roll out switch tomorrow and see if that makes a difference.

 

[Jim greengo]

I’d jump out the rollout and see what happens.

And watch the burners when it kicks on when cold,also check it after heater gets warmed up.
Sometimes cracks open up after the furnace gets warmed up.

 

[Jim greengo]

Not sure what an actual 'roll out' looks like. There are 3 flames. The bottom flame is pure blue, second is blue with some yellow, and the top is blue and orange. The only lapping of the flame is from the middle flame to the top flame along the channel for lighting. I took out the burners last week and crimped the top channel to decrease the flame lapping. Hope this makes sense. The company sent me a new regulator because of lack of pressure and flames were all orange. Noticeable difference with new part.

I'm going to jump the roll out switch tomorrow and see if that makes a difference.

Flames will roll out front of furnace and set off roll out switch.

 

[spudley]

If you remove the front cover (the piece that has BigMaxx printed on it) you'll see the roll out sensor. Easier to replace from the front but you can jump it w/o removing the front cover.

I'd move the unit out of the box and try it. When running those blower fans **** in lots of air creating a negative pressure situation. Might not be enough left for proper combustion.

Did your HVAC tech do a combustion analysis?

 

[acmikee]

hot air rises if your tstat is at 4' and the unit is at 8'+ located inside of a box what is your return air temp and supply air temp remove the box that is around the unit and your problem will probably go away.

 

[Vermont]

Sorry for the delay. I'm diving into this heater this weekend, and trying your suggestions. I'll let you know what I find.....

 

[fitter30]

Look at the burner before and after the fan kicks on to see if there is a difference in the flame. If there is could have a cracked heat exchanger.

 

[Aileron]

Starving for air. Its restricted being in that box. You are trying to pull air thru the heat exchanger plus trying to pull air in for combustion. What you are pulling back is already heated and could be pulling against the combustion fan causing a negative effect after it runs a bit. When the fan motor goes out , how do you get to it? "Think take it outside the box".

 

[Vermont]

I've been tweaking the heater most of the day. Thanks for all your great suggestions. Here's the break down...

- Uninstalled the heater and reinstalled outside the box.

- Heater ran for 1.5 hrs before tripping the roll-out. Usually runs about 20 mins and then trips the switch so things were looking better.

- There was still subtle roll-out of the flame so I removed the metal tubes after the orifaces where the combustion takes place. I crimped all the channels that the flame travels on to light the next burner.

- Restarted heater and it ran for 3 hours with no issues.

I'm now spending tomorrow building a mount for hanging the heater...OUTSIDE THE BOX.

Thanks for all the suggestions and help on this.

P.S. The pic of the heater on the stack of wood...all those pieces are screwed together with 3 inch screws. It looks crazy as **** but it's all solid as a rock....

 

[D45]

I did the top burner pinch and also welded it shut, to prevent any top flame rollout

Haven't had an issue since

 

[spudley]

The pic of the heater on the stack of wood...all those pieces are screwed together with 3 inch screws. It looks crazy as **** but it's all solid as a rock....

On the second picture, what's the glow between the lower burners? The top burner looks fine but do I see an amberish glow between the other two? Is that the ignitor?

 

[94toyotapickup]

I was having the same issue. After the fan at the back of the unit went bad and was making a lot of noise I replaced it with a new one. After replacement I continued to get the 4 blinks and the thermostat would shut off and turn back on after 15 mins or so of run time. I was frustrated. I thought to myself what if the pitch of the fan got messed up after install. So I took the fan blade off the motor and made the pitch larger and made sure all blades were the same. Low and behold this fixed the issue with the 4 blinks. Now I can use my heater without any errors. Also I took a flat screwdriver and hammer and pinched / crimped the coupler on the fan blade assembly. It seemed loose before and is what was causing the fan vibration humming noise. Worked wonders. Hope this helps.