Mr. Heater Big Maxx Problem

[xfiring]

Well got the heater hung, gas run, and b-vent done. Heater fired up first time (great right?). After about 15 minutes it started blowing cold air. Turned thermostat OFF and the fan was still on blowing cold air. Unplugged the unit let it rest for 10 minutes, plugged back in. Fan immediately came on even though thermostat was still off.

The LED blinks 4 times indicating a high sensor limit or rolloff valve. The unit was cool (read not hot) so I tried to reset the rolloff valve, but low and behold not even listed in the schematic of all the parts.

So here I am very upset. Any ideas other than 'the circuit board is bad'? I ran 4 wires to the unit and the thermostat has 4 wires (the cheapest honeywell I could find). Before firing up the unit the fan auto/on turned the fan on with no problems.

Thanks.

 

[Junkman]

The thermostat is probably wired wrong. If the fan is on, then there is something wrong in the circuit. The blower should stay on till all the heat is out of the heat exchanger. Check your wiring again. Does the thermostat have a sub base? If so, is the fan set to ON??? Is the thermostat level.. If not, then the mercury switch might be calling for heat, even though the room is warm enough.

 

[dropride]

My hot dawg has done that since i installed it a few weeks ago. One of the flame roll off switches keeps tripping. If you look near where the flames come out of the tubes there is one at the top and bottom if it is a sinilar unit. There are 2 red wires running to each with a reset in the middle you have to push in. Havent had time to call the manf. to see how to fix it.

 

[xfiring]

Thanks, will try both today. What two wires do I twist together to bypass the thermostat to make sure that isn't the problem?

 

[TRDon]

Jumper the R and W or C on the unit. That will call for heat.

 

[xfiring]

Will try that too, we wired it Yc to Yellow, W to white, R to red, and G to green. Does that seem right to everyone?

 

[Mellotron]

Y(Yc) is for cooling, I don't know where you got that from, disconnect it immediately on both ends. Per the heater manual you only need two wires. R(Rh) and W only. You can optionally connect G if you want control the heater's fan manually for circulation. So three wires Max for the Big Maxx.

Also double check your thermostat manual. Sometimes they make you run a jumper across Rh and Rc. If you have that, probably not.

If all else fails, take the T-Stat out of the picture completely for troubleshooting. Jump the R and W at the heater then check for proper heater operation.

Added some pictures from manual:

 

[xfiring]

Disconnected Yc didn't change anything. Still on immediately. Going to try to troubleshoot more tomorrow.

 

[BigChevy80]

Disconnected Yc didn't change anything. Still on immediately. Going to try to troubleshoot more tomorrow.

I would just disconnect the thermostat altogether and see what happens then. If it comes on with nothing hooked up then you probably have a fried control board.

I'm kinda glad I didn't go with a Big Maxx now that I've heard 3 or 4 different stories about bad boards right out of the box...

 

[Junkman]

If people don't follow instructions, then how is it the manufacturers fault that they fry the circuit boards. No different than hooking up jumper cables incorrectly and frying the cars electrical system. Give me a break......

 

[dropride]

The fan will continue to run as long as it is still blinking that code. You need to reset the flame rollout switch.

 

[83trekker]

"I'm kinda glad I didn't go with a Big Maxx now that I've heard 3 or 4 different stories about bad boards right out of the box...[/QUOTE]


I couldnt be happier with my Big Maxx straight out of the box, theres prob hundreds of thousands of heaters sold, and you have read about 3 or 4 with probs, half the time it is the consumers fault of hooking it up wrong. For the price i would totally recomend this heater and from what i hear customer service is really good too.

 

[Junkman]

Now is the time to start watching Northern Tool if you have a heater in your immediate future. They are starting to sell them off at a discount. The Big Maxx 75,000 BTU uniti is reduced from $499 to $429... In a few weeks, it will probably hit $399 based on past experiances.

 

[Shocker]

I just bought my 45k btu for $339

 

[Mellotron]

I just bought my 45k btu for $339

OH! UH! Not cool! I paid 379.00 and it arrives tomorrow. I'm emailing them now. Hopefully they can show me some love or I'm sending Junkman in to cut off their kneecaps.

 

[Junkman]

OH! UH! Not cool! I paid 379.00 and it arrives tomorrow. I'm emailing them now. Hopefully they can show me some love or I'm sending Junkman in to cut off their kneecaps.

Oh........ great..... just what I need.. to beat up some more idiots.. Just tell them that the Junkman said to give you the refund, and they will. My reputation is enough to get them shaking in their boots...

 

[xfiring]

We did not install it wrong, my dad is here and is an electrician and we are both extremely handy.

We finally got it to work after 7 hours on the phone with Mr. Heater support. It required entire disassembly of the unit and modifying parts inside. It now works and is great. Should I have gotten the modine for 200 extra bucks, absolutley. Does it work great now, yes. Should have worked out of the box and not required this much effort.

Also, the included directions were the absolute worst I have ever seen. If anyone disagrees with that statement, they are LYING! There was not even one mention of how to wire electrical or thermostat. And that stupid die cast 3 to 4" adaptor was ridiculous.

 

[tim096]

You were on the phone for 7 hours, with mr. Heater support. WOW I give you both alot of credit. I have a Mr. Heater 75000btu. It has been great. There is no way on earth I would spend 7 hours on the phone.

 

[BigChevy80]

If people don't follow instructions, then how is it the manufacturers fault that they fry the circuit boards. No different than hooking up jumper cables incorrectly and frying the cars electrical system. Give me a break......

One break, comin' up.

In the handful of cases I'm referring to, not one was hooked up incorrectly. Could they be lying to cover their asses? Sure. Are there thousands of happy, satisfied customers out there? Probably. Is this something worth bickering over? Not in my opinion. I was simply making the observation that I've heard a lot of stories about fried boards on this certain brand, that's all. Sorry if I ruined anyone's day over it...

 

[Mellotron]

We did not install it wrong, my dad is here and is an electrician and we are both extremely handy.

We finally got it to work after 7 hours on the phone with Mr. Heater support. It required entire disassembly of the unit and modifying parts inside. It now works and is great. Should I have gotten the modine for 200 extra bucks, absolutley. Does it work great now, yes. Should have worked out of the box and not required this much effort.

Also, the included directions were the absolute worst I have ever seen. If anyone disagrees with that statement, they are LYING! There was not even one mention of how to wire electrical or thermostat. And that stupid die cast 3 to 4" adaptor was ridiculous.

Right on! Glad you got it healed up. Enjoy the warmth! I'll be installing mine next!

 

[dropride]

What needed to be modified? I called modine today to try and get some tech support for mine and they wouldnt even talk to me cause i am not a contractor.

 

[Steve Szakats]

I called modine today to try and get some tech support for mine and they wouldnt even talk to me cause i am not a contractor.

When I first installed my 45,000 unit, I hooked up the thermostat wrong (my mistake...my eyesight *****), and fried the motherboard. They sent me a new one with an appropriate inline fuse installed. This was over a year ago.

I called them 2 weeks ago about the external fan starting to whine and they sent me a new blower, no questions asked. They didn't even ask me for a serial number or a purchase date! Of course they sent me the internal fan instead of the external one, so I called them back and again, they sent me the correct part no questions asked. And told me to keep the other blower!

I have no issues with their customer support.

 

[dropride]

What# did you call. They seemed less than willing to give me any support. I got the phone # for the rep in the area and he wouldnt even help me cause i wasnt a contractor. Liability reasons he said.

 

[Steve Szakats]

What# did you call. They seemed less than willing to give me any support. I got the phone # for the rep in the area and he wouldnt even help me cause i wasnt a contractor. Liability reasons he said.

1-800-251-0001 the company is Enerco. If you're on hold for a while, you can eventually leave a message and they call you back promptly.

 

[RFears]

Mine did same thing, flame needs to be adjusted, it doesnt need to go around corner of pipe, on top of gas valve you will find a screw that covers the adjustment screw. remove cover screw and start heater, you will able to adjust flame by adjusting screw. You have to watch flame as you turn screw. Heater will work fine after u lower flame. It can't go around the turn in the heat exchanger....

 

[beetroot72]

What needed to be modified? I called modine today to try and get some tech support for mine and they wouldnt even talk to me cause i am not a contractor.

Modine or big max support? I had a plague of problems with my first hot dawg (modine) due to "dirty Power":... and modine was by far the best company I have ever delt with! I will give you my contact over there if you send me a PM. I don't want to beat this guy down with tech calls.
I was Modine Mfg. deciding reason to Dump the honeywell "smartvalve"

 

[don_tina]

just bought a mr heater 75000 btu ng. wired to a themostat used only the r and w wire heater runs for about 5 minutes and flame kicks out and just the blower runs. after reading the manual and the number of blinks on the green light . figured out that the rollout switch had tripped. i reset the switch, turn the unit back on and it ran for about 15 minutes and tripped again. reset again and it ran for another 15 minutes and tripped for the 3rd time. does any bodu have any solutions. only the top sensor is tripping. the flame is nice and blue, it doesnt appear to need any adjusting.

 

[Ryano121]

Don Tina, did you ever come up with a solution for this? Mine does the exact same thing. I can reset the sensor every 15 minutes, but nobody wants to do that!!

 

[98xjroks]

Re: Modine 60k Problem

Don Tina, did you ever come up with a solution for this? Mine does the exact same thing. I can reset the sensor every 15 minutes, but nobody wants to do that!!

Me three....Brand new heater and this occurred first time I turned it on and everytime.

 

[Deltarat]

I bought mine in 08 and it ran a month or so and quit. They said I had a bad board and sent me one. It was bad right out of the box. They admitted they were having trouble with the boards and sent me another one. It has been working fine ever since.

 

[68SS2]

I want to buy a Sterling 45k heater that is very similar to the Big Maxx or Big Dawg. On the Sterling you can pull fresh air from outside to burn then vent back outside the garage. The Modine and Sterling cost about the same. Does anyone have any hard feeling about either one of these, except the combustion separation feature, why I should buy a Sterling over a Hot Dawg or vise versa?
Thanks
If this is a thread hijack, just tell me and I will fix it.

 

[jumpingryan]

I own a Sterling Garage Guy Heater.... the thing is that I have only installed it, and uninstalled it as I am moving over the next few months due to work related reasons (and I didn't want any prospective home buyers trying to include it in the deal)

As far as I can tell, they are pretty much the same as any other heater, minus the separate combustion intake. They are of slightly higher cost than the Big Maxx or other comparable heaters, yet with their higher cost, I consider the Sterling of higher/better value.

The separate combustion doesn't have to be used you can hook it up any way you like, not necessarily in the concentric vent option..... without a separate vent, they are just like any other Big Maxx/Modine model.

They come with a propane conversion part for future use. Mine is natural gas from the factory.

Having done alot of research into just about all models, and a complete vertical flue installation (with no hook-up of gas due to my future moving situation.... however the flue is proper for the future home buyer to use), I don't regret my purchase even though I havn't used it yet due to my circumstances.

On my next home, I will be purchasing a concentric vent box and using outside air for combustion. It is just far too safe/ease of installation of an option vs price to go without...... Peace of mind & a quality setup are important to me, as I will be leaving the heater with this house (this house will be my in between house for a few years)

The next property after I choose my upcoming home will be acreage, with in-floor heating in the garage & house, hooked to a wood boiler.....

I love in floor heat, but I am willing to wait for it in my upcoming dream shop/property/home (order to be determined by myself..... with the wife's input.... or perhaps the other way around! LOL)

Anyways, hope the Sterling serves you well in the future, even though, as an owner, it hasn't yet (but will) served me well!!!

R

 

[Chad M]

just bought a mr heater 75000 btu ng. wired to a themostat used only the r and w wire heater runs for about 5 minutes and flame kicks out and just the blower runs. after reading the manual and the number of blinks on the green light . figured out that the rollout switch had tripped. i reset the switch, turn the unit back on and it ran for about 15 minutes and tripped again. reset again and it ran for another 15 minutes and tripped for the 3rd time. does any bodu have any solutions. only the top sensor is tripping. the flame is nice and blue, it doesnt appear to need any adjusting.

I just installed a Dornback 30K unit and had the exact same problem. I narrowed the problem down to the upper roll out switch, mine has two. I contacted Dornback and the tech told me that the upper roll out switch just might be getting too warm in that location and that I could bypass that switch and run just the lower roll out switch. I watched the entire cycle and saw nothing unusual about the flame, no roll out, no overheating. I disabled the upper and the unit now works as advertised. I also could have replaced the switch or just swapped the upper and lower positions to determine if it was the switch or just a poor design. No advice here, just relaying what I found out.

 

[jgump]

I just installed my new 75K Mr Heater and I am having the same issue as the original poster. Does anyone know of a quick fix? The HiLo / Rollout switch keeps tripping?

Thanks

 

[jgump]

Here is the fix..... Basically you take out the top burner and pinch shut the top fan (I used a vise). The bottom fan on the top bruner is still required for lighting. I'll try and post the pic when I get a moment.

From Mr. Heater:
The Big Maxx unit heaters have one or two roll out sensors and one high limit sensor heat exchanger to monitor over heating or flame blowing back into the burner box.

A common problem on these units is the LED on the circuit board giving a 4-flash code ‘High limit or rollout switch open’. The problem that causes this is that the burners that the flame comes out of, are designed to overlap their gas so as the bottom burner lights up the gas and flame hit the gas from the burner right above it. So each burner lights up one after the other. The top burner doesn’t have a burner above it to light up but the gas and flame still comes out. This little extra flame hits the heat exchanger tube before being sucked down into the tube. This flame than causes the upper mounted rollout heat sensor to go off and the heater shuts down. You can reset this rollout heat sensor with the little reset button that is located between the wires that plug into the back of it. It is located at the top of the burner assembly behind but not on the circuit board.

To fix this problem, you will need to remove the top burner and pinch together its edges per the pictures below. Remove the burner side plate, than remove the two screws that hold the burner in place and pinch or hammer the top edge, just above the center hole to stop this extra gas path.

 

[jgump]

Fix with pictures in PDF attached.

 

[CorporateOffRoader]

this is the second winter for my 75K Big Maxx unit and no issues yet, is there a production window that is affected?

 

[jgump]

No idea. I bought mine at Lowes in October. So far the fix has worked.

To me it is a design flaw. I may also turn down the flame a little as a previous poster suggested. My flame goes past the turn in the heat exchanger.

 

[Zvacman]

I have been using my 75,000 btu unit since Oct. without any problems. Last night my unit started just blowing cold air and the fan won't shut off even with the t-stat turned off. Luckily I have a habit of over building/engineering everything and I installed a switch in the wiring going to the unit so I was able to kill the power to it and shut the fan down. It looks to me from what I have read that I need to pinch the top burner off. I will do it today and let you guys know how it works. What I don't understand is why didn't the unit do this from the beginning if it is indeed a flaw? I wonder if they make an upgrade piece to fix what appears to be a defect by them.

Zvacman

 

[prolawnsvc]

Mine is doing the same thing. I just checked my switch and it does not appear to be tripped. If it is tripped I assume it would be sticking out and I would push it back in to reset. However mine is in and i can not push it in any farther. Mine worked for about a month and just tonight stopped. How do I get the unit to stop flashing 4 blinks?