Interthem furnace problem
#1
01-20-22, 03:39 PM
Interthem furnace problem
Intertherm Model MMHA 056AAHR 05. Intermittent problem, thermostat calls for heat, furnace does nothing. I turn the thermostat way down then up again and it starts working normally. Works for a day or so and then same problem. Very frustrating. I did get a 4 red flash error code on the control board but never had to kill the power to reset, just did the thermostat down and up thing to get it going. I'm thinking of replacing the control board, any other ideas?? Thanks Terry
#2
01-20-22, 06:36 PM
Group Moderator
Welcome to he forums.
Yes..... call for service.
Don't throw parts at it.
Usually a 4 flash fault is over heating. The codes are listed on the back of the blower door.
If that's overheating..... check/replace air filter, check for closed register, check for blocked returns. An over heat issue is usually due to lack of airflow.
I'm thinking of replacing the control board, any other ideas?
Don't throw parts at it.
Usually a 4 flash fault is over heating. The codes are listed on the back of the blower door.
If that's overheating..... check/replace air filter, check for closed register, check for blocked returns. An over heat issue is usually due to lack of airflow.
#4
01-21-22, 06:22 AM
According to what I've read 4 flashes indicates a lockout. Nothing listed on my door. I don't know how it could be overheating, the unit does not even come on, cold as a cucumber. On the control board it says "reset thermostat in case of lockout".
Like I said, very intermittent problem, just got it going again this morning after resetting the thermostat and now it will probably run fine all day.
My induction motor has a centrifugal switch, not vacuum.
Like I said, very intermittent problem, just got it going again this morning after resetting the thermostat and now it will probably run fine all day.
My induction motor has a centrifugal switch, not vacuum.
#6
01-21-22, 09:59 AM
Group Moderator
I'm having a hard time finding servicing info on that older Nordyne motor home furnace.
Please post the part number off the control board.
Please post the part number off the control board.
#7
01-22-22, 06:47 AM
It's a United Technologies 1018 SERIES HOT SURFACE INGNITION
I finally found out what the error codes mean on the controller, 4 flashes indicate lockout due to failure of some component in the controller. I have a new one ordered and will post an update once installed. I'm also planning on replacing all 3 limit switches as well.
I finally found out what the error codes mean on the controller, 4 flashes indicate lockout due to failure of some component in the controller. I have a new one ordered and will post an update once installed. I'm also planning on replacing all 3 limit switches as well.
