Big Maxx heater operation

[Blueline]

Hey guys quick question, I’m hoping someone with a big Maxx heater can help answer. I installed an 80k btu big Maxx heater in the spring during my garage addition. I just kicked it on as it’s getting cold and also so it could burn off any coatings from manufacturing and shipping.

My question is, as long as the thermostat is calling for heat, the fan stays on and the burners will run for a few minutes, then turn off for a few minutes, fan stays on, then the burners lights again for a few minutes, repeating the cycle. So basically the burners cycle on and off and the fan stays on constantly as long as it’s calling for heat. Does this sound like normal operation?

Sorry for the dumb question but can’t find anything in the manual or online that describes normal operation and they are closed until Monday.

Thanks for the help!

 

[pbon]

How big is your garage?

 

[Blueline]

It’s 47x25

 

[The Cobbler]

no answer other than the burners should stay lit until the stat stops calling

 

[pbon]

Did you use a fancy thermostat with multiple wires that could make the fan always on or a simple 2 wire? I use a 2 wire and my Big Maxx 50 does not run the fan constantly between burner cycles.

 

[Blueline]

Did you use a fancy thermostat with multiple wires that could make the fan always on or a simple 2 wire? I use a 2 wire and my Big Maxx 50 does not run the fan constantly between burner cycles.

I used the two wire thermostat from mr. Heater. The fan comes on and off as it should, it’s just the burners turn off for about 30 seconds then re ignite for another few minutes then turn of again for 30 seconds and then re ignite for another few minutes. It’s almost like the tubes get to a certain temp, once they reach that temp, burners turn off, tubes cool to a certain temp and they re ignite.

When I initially fire the unit in a cold garage the burners will stay on constant for 10 minutes, then do the re ignite sequence every few minutes.

 

[On-Wheel]

Thermostat getting hit by the heat? Is it too close? Tape something over thermostat if your unsure. It could be a sensitive thermostat?

 

[Blueline]

No it’s not the thermostat, the fan runs as long as it’s calling for heat. When temp is reached and thermostat kicks off, everything turns off as normal. It will initially run for say 12 minutes, turn the burners off for exactly 30 seconds, then re ignite. It then will run for another 7 minutes or so, turn the burners off for 30 seconds then re ignite and run for say 5 min and repeat the process.


But, I just took the side panel off so I can double check all burners are firing and monitor the led light when this happens. With the side panel off it’s running constant and not cycling. Weird, so is something getting hot and causing the burners to restart?

 

[Racy2]

I would call Big Max and ask them if this is the way they are designed to operate. I am sure they can answer your question or know why it is doing this.

 

[Blueline]

I would call Big Max and ask them if this is the way they are designed to operate. I am sure they can answer your question or know why it is doing this.

Yes, I am calling them in the morning, unfortunately they are closed on the weekend. I was hoping someone on here who has one could confirm this is normal operation. I did have the panel off and left it running and it ran for 45 min without turning off. And the LED just fast flashes indicating normal operation.

 

[klassenl]

First: lower the stat below the room temp. Turn off the heater at the breaker. Wait 30 sec. Turn the breaker on then turn the stat up. Does the fan turn on with the stat or does it fire for a minute before the fan kicks on.

If there is a delay before the fan comes on that would suggest it's working properly. If there's no delay that would suggest either a wiring problem or a control problem.


If there is that delay do this. Pull the stat off the wall and hang it from the heater with a short piece of wire. Make sure it's wired right. Set it to a low temp, just barely above the existing temp. Then let it go. This way you eliminate hot air from the heater influencing the stat.

 

[Blueline]

First: lower the stat below the room temp. Turn off the heater at the breaker. Wait 30 sec. Turn the breaker on then turn the stat up. Does the fan turn on with the stat or does it fire for a minute before the fan kicks on.

If there is a delay before the fan comes on that would suggest it's working properly. If there's no delay that would suggest either a wiring problem or a control problem.


If there is that delay do this. Pull the stat off the wall and hang it from the heater with a short piece of wire. Make sure it's wired right. Set it to a low temp, just barely above the existing temp. Then let it go. This way you eliminate hot air from the heater influencing the stat.

Thanks for the reply buddy! Yes, when the thermostat calls for heat it’s doing the proper start up, exhaust blower kicks on for 20 seconds, then burners light and a few seconds later the large fan turns on. It will run like this for about the first 12 minutes with no problem, still calling for heat, the burners turn off for exactly 30 seconds then they re light and continue to burn for about another 7 minutes. Still calling for heat, the burners will shut off for exactly 30 seconds again and then re light continuing the cycle. Once the thermostat stops calling for heat, the burners shut down, exhaust blower shuts down and then the large fan turns off like normal. My question is should the burners be cycling every once in awhile during an extended call for heat.

Oh and this time when it cycled I was able to monitor the LED light and it continued to flash indicating normal operation, while this cycling is occurring. So maybe this is how it is designed to operate?

Thanks

 

[hotrod1968]

Thanks for the reply buddy! Yes, when the thermostat calls for heat it’s doing the proper start up, exhaust blower kicks on for 20 seconds, then burners light and a few seconds later the large fan turns on. It will run like this for about the first 12 minutes with no problem, still calling for heat, the burners turn off for exactly 30 seconds then they re light and continue to burn for about another 7 minutes. Still calling for heat, the burners will shut off for exactly 30 seconds again and then re light continuing the cycle. Once the thermostat stops calling for heat, the burners shut down, exhaust blower shuts down and then the large fan turns off like normal. My question is should the burners be cycling every once in awhile during an extended call for heat.



Thanks

Mine does not operate they way you are describing. It goes through it normal start up when heat is called for. Turns off when desired temp is reached. No cycling of any sort.

Sent from my SM-G965U using Tapatalk

 

[Blueline]

Mine does not operate they way you are describing. It goes through it normal start up when heat is called for. Turns off when desired temp is reached. No cycling of any sort.

Sent from my SM-G965U using Tapatalk

Ok thanks for the reply!

 

[Ziomarco]

Sounds like maybe your high limit switch is tripping. Are you getting an error code when this happens?

Marco

 

[Blueline]

Sounds like maybe your high limit switch is tripping. Are you getting an error code when this happens?

Marco

No errors, LED always flashes normal operation.

 

[Dagny]

not normal.

 

[Blueline]

Ok so I figured a few things out. There is a high limit sensor in the heat exchanger. That can trip and not set any codes, simply reset once the temps come back down to normal range. A few years ago we did a pool install and a 400k btu pool heater. The gas company had to come install a new meter for the high demand as the pool heater was also 350’ from the meter. Since then I have always felt the gas pressure was high. I did a built in grill during the pool build and always have to have the shut off valve at the grill cracked only 1/2 on a. 1/4 turn valve.

So I went into the garage and cracked the shut off valve closed a little. I could see the flames tame down a bit and looked good. The unit ran for almost 40 min until I shut it off. I was taking temps of the tubes and in the heat exchanger and they were definitely lower than before but still kicks out a ton of heat. The tubes are about 400-550* per my infrared thermometer. So I guess it was just getting too hot in the box setting off the high limit sensor. So looks like I will need to get a manometer and check the pressures and adjust accordingly.

I appreciate all the help and suggestions. Thanks again

 

[pbon]

Good job thinking it through and figuring it out! I am happy mine worked perfectly right out of the box, but it is good to know mire about how they work.

 

[theundermount]

glad you got it all figured out, definitely did some very good leg work for anyone else having a similar issue! thanks for posting your outcome

 

[Blueline]

Thanks guys. So its looking like it was nothing with the unit itself just a gas pressure adjustment and I should be good to go. I love the unit and it raises the temp in my garage nicely. Cant wait for winter now!

 

[aardquark]

Another thing to consider is a mismatch between the jets and the type of gas you are using (propane vs. natural gas).

 

[Blueline]

Another thing to consider is a mismatch between the jets and the type of gas you are using (propane vs. natural gas).

Thanks Bud looks like the jets are good. Mr. Heater seems to think it was air in the new gas line. We are going to monitor it and I will be keeping them in the loop. There are no codes or anything.