How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Richard Your Own Question
Richard, Technical Manager
Category: HVAC
Satisfied Customers: 1514
Experience:  27 years of Experience, NATE Certified, professional trainer
Type Your HVAC Question Here...
Richard is online now
A new question is answered every 9 seconds

Arcoaire Enviroplus 90 light blinks 6 consecutive times.

This answer was rated:

Arcoaire Enviroplus 90 light blinks 6 consecutive times. Code only goes up to five and then says that continuous blinking indicates flame detected when no heat is called.

small fan turns on, pilot lights the gas and then all shuts down. Continuous cylce of this until it does eventually turn on. Changed the thermostat and that worked a day or so to fix it. Changed the filter and thought that helped as the filter was pretty dirty. But is now again back to cycling thru to the point of ignition of gas and then shutting down.

Hello one thing you may want to check here is the flame sensor. If there is rust or debris or it somehow is shorting to ground you will get this code. Now, the dirty part should not do it but is something has it shorted to ground it will sense flame when there is no flame.

The flame sensor is a tin metal rid near the burner where the flame goes into the heat exchanger. Turn power off before e you do anything. Let me know what you see Richard

Richard and 4 other HVAC Specialists are ready to help you
Customer: replied 6 years ago.
I will check out the sensor, but the HVAC shuts down when it does detect flame. So it would seem the sensor is working. It isn't shutting down until after the gas is ignited.
Hello make sure it i clean. If flame is present and it is not shorted it may be just dirty. Let me know how it goes and we can go further. It could be a board failure but lets do a few things first. Richard
Customer: replied 6 years ago.



I will go take a look.

Customer: replied 6 years ago.



I will go take a look.


I should have added, that if I turn the thermostat on, it will ignite and continue to run and heat like normal. The cycling on and off occurs when it appears to me maintaining a constant heat.

Customer: replied 6 years ago.

The flame sensor, if that is what I looked at, appears to be in good shape. It is a tin refector with a sort of charcoal looking device with two wires attached and the wires go to the board in the bottom chamber.


The sensor is in the box where the gas chamber is at. right?

Hello no this is the igniter the flame rod will be a thin metal rod on the oposite side. It should have 1 wire going to it.
Customer: replied 6 years ago.
Please allow me to heat the house back up before I continue. It is running right now and the temp went down pretty quickly. So I will check this out soon I am sure.
Customer: replied 6 years ago.

Please allow me to heat the house back up before I continue. It is running right now and the temp went down pretty quickly. So I will check this out soon I am sure.


I have pulled the sensor. It appeared to have a dirt or carbon type build up on it. Installed in 1998. I cleaned the dirt off with steel wool and put it back in the chamber. I have turned the heat back on and am waiting for a cylce to see if it continues to cycle often.

Customer: replied 6 years ago.

The system ran through a cycle and 5 minutes later started up again. This time it cycled correctly, or in other words, it ignited the gas and continued to run.


I understand that there might be a way to extend the time on the cycle period so it does not come back on so soon. I will wait to see if the system cycles through and works again one more time, but in the mean time, I am concerned about how soon it kicks back on after running a cycle. I bought a new honeywell theromstat, but do not see any way to set it any different. Can you tell me if there are dip switches I can set that would give me more time between cycles.

Customer: replied 6 years ago.
It passed a second cycle test, so I think you may have got me going. I continue to be concerned about the quick turn around. It is only off about 5 min and the cycle begins again. It is cold outside today and windy, so perhaps I shouldn't be so concerned, but it still doesn't seem right that it goes on so often. The thermostate never leaves the 68 degree reading, so I think it is set for too much comfort and not enough economy. There is bank of dip switches on the control board, and I think they may be for this setting, but I don't know how to set it. Would you have a manual or a way to tell me how to set these if I am right?
Customer: replied 6 years ago.

Are you there?

Hello I am glad to hear. I was off last night and little under the weather
Customer: replied 6 years ago.

I will need to continue this, if you are willing, later tonight. I have a 10 hr. task in front of me today and need to get to KC. Is it possible that you could look over my last correspondence and tell me if there is a way to reduce the time between cycles. (i.e. heat longer and then longer period of time before heat is called for again)


I found dip switches that set heat on delay and heat off delay, but I don't know if these switches are the answer to my question. There are directions for the settings next to the switches.


It is nearing 0 degree here, so I am not terribly concerned about the rapid cycling, but I just don't ever remember it before. Had the system since 1998. I have already accepted your answer, but I plan to add a bonus if you stay with me. Thanks so much.

Hello the cycle rate will be programed in the thermostat the furnace only know power then no power. Depending on the type of t stat you have you can increase or decrease the number of cycles per hour. Since it is getting cold it will cycle more as it is judging the heat loss of the home. This is my multi stage is very popular today longer run cycles equal less cycling and improved comfort and efficiency. Do you know what type or model of t stat you have Richard
Customer: replied 6 years ago.

Thermostat is a Honeywell. It advertises that it has an automatic detection of how long it takes to heat the house when using energy saving settings at night for example, but it did not give an option to set the number of cycles per hour. I think a 5-2-2

Hello if you pull the cover off and get me a model i could look it up. Auto features don't always work the way we want them to and we may be able to adjust.
Customer: replied 6 years ago.
graphicThis is the only number I could find.
Customer: replied 6 years ago.
I just purchased the thermostat at Menard's. Going through the settings, it appears to bbe 5-2 (weekday/weekend) with 4 different day settings.
Hello yes if you press and hold the up arrow and fan button this will put you into the configuration mode use the arrow keys to scroll through and make sure it is set correctly for the type heating system you have then setting or function 5 will be the cycle rate set it to 5. Also, keep in mind if the temp is dropping fast due to the cold the t stat may just be responding normally. If it heats the home to temp then cycles off and the thermostat temp drops ( you see this on the screen) it may be responding normally and your home is loosing heat fast or the thermostat is being influenced. make sure it is not on an outside wall or the wall on the other side is a non heated room. Richard
Customer: replied 6 years ago.

graphicgraphic graphic graphic


When I hold the fan and the up arrow, it must place it in config like you have suggested, but it is not clear to me (no indicators) as to what is getting adjusted. I am not getting a function 5. It goes from function 2 to 13 I think. Do you have a link to a manual I can look at?

Hello I am out of town and traveling and can not get the link to work on this computer. However you can go to type in the RTH6350 model and it will come up.

On page 14 to 17 is how you do this. Richard

Customer: replied 6 years ago.

We keep the temp at 68 most of the day. It will cycle, even though the temp always reads 68. So the temp is not dropping that rapidly as to make it go on again, but it must be coming on all the same due to attempting to maintain the temp. I did get it set at function 5 at 5. The system is 90% efficient so I believe you are correct to tell me to use 5 and not the other setting for gas heat high efficient over 90%.


When I installed the thermostat this manual on site was in the box. Sure wish I knew where it went. Oh well. Since I cleaned the heat sensor, the issue of shutting down unexpectantly has gone away (I have not noticed it and I have listened for it). You were spot on from the beginning. Thanks so much for your help on a Sunday. I hope you keep doing this.



Glad to hear it, sorry got stuck in traffic today

Related HVAC Questions