are you sure it's a roll out and not a limit? if so, check the hx. i find it odd you changed the board and blower motor at the same time. was it flooded or something?
Hi All,
I replaced a blower motor and a WR control board on a Amana GUCA 13 year old furnace worked 1 day then no heat fan run all the time. Tripped out on roll out reset and furnace runs great for 5 starts and no sign of any rollout. Next day no heat same thing no signs of roll out with and without cover on. kind of weired worked ok until I had to replace fan and board. Any thoughts
are you sure it's a roll out and not a limit? if so, check the hx. i find it odd you changed the board and blower motor at the same time. was it flooded or something?
could it be a crack in the heat exchanger that's only opening up after the furnace runs for awhile?
Replaced the blower motor on start up the board died.
good point maybe when the HX gets hot it open up.
Delta T? Dirty air filters? Collapsed duct work? Dirty Evap coil?
I'm thinking airflow since the problem occurred after you changed blower motor and control board.
How did you set your fan speed?
Have you tested the RO switch to see the point that it opens? Those things are made in china.
__________________________________________________ _______________________
Experience is a hard teacher because she gives the test first, the lesson afterwards" ~ Vernon Law
"It's what you learn after you know it all that counts." ~ John Wooden
"When the teachers become unteachable we're all in trouble" ~ Mr. Bill
"Remember "Pro" is only a name, it's not always a mindset determined to do everything correctly" ~ Mr. Bill
If its the roll out and not the limit I would not think it has anything to do with the blower and board replacement. I would be looking at the HX and venting.
__________________________________________________ _______________________
Experience is a hard teacher because she gives the test first, the lesson afterwards" ~ Vernon Law
"It's what you learn after you know it all that counts." ~ John Wooden
"When the teachers become unteachable we're all in trouble" ~ Mr. Bill
"Remember "Pro" is only a name, it's not always a mindset determined to do everything correctly" ~ Mr. Bill
could be the secondary hx is plugging up I had a carrier do the same thing would work ok for a couple of days and intermittently trip the rollout switch, while you had the blower out did you check the secondary hx?? I have had a lot of the secondary hx plugged with dirt and pet hair. Is it the same rollout switch tripping?? Can you try swapping it with one of the other rollout switches assuming it has more than one, to see if it is a bad switch??
Sure. But not likely this "Grand Canyon" crack appeared at the same time the blower was replace. With no symptom of the crack before.
Where is the furnace getting it's combustion air from? Is it located in a closet?
"The bitterness of poor quality remains long after the sweetness of low price is forgotten". --Benjamin Franklin
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is the new blower motor right rotation?
The orig call was no heat and had a bad blower motor replaced the motor and the board died replaced both and furnace ran great for several cycles and left. 24 hrs later tripped on roll out, reset and ran great. 24 hrs latter again it happend. Going back soon. With the blower motor not working and burners cycling for at least 12 hrs
could it have burned a hole in the HX and it starting showing up after blower was changed?
Dex1
__________________________________________________ _______________________
Experience is a hard teacher because she gives the test first, the lesson afterwards" ~ Vernon Law
"It's what you learn after you know it all that counts." ~ John Wooden
"When the teachers become unteachable we're all in trouble" ~ Mr. Bill
"Remember "Pro" is only a name, it's not always a mindset determined to do everything correctly" ~ Mr. Bill
Those rollout switches do not always have to have flame rollout to trip. It can get plenty hot in that area while the thing is cycling on limit. Curious if that switch was tripped when you first went on the no heat call. As far as the board I have seen plenty of boards fry when a motor goes bad especially those amp sucking 3/4 hp units. To me it's a wonder those micro contacts in those board relays don't die faster than they do considering the load they are switching.
__________________________________________________ _______________________
Experience is a hard teacher because she gives the test first, the lesson afterwards" ~ Vernon Law
"It's what you learn after you know it all that counts." ~ John Wooden
"When the teachers become unteachable we're all in trouble" ~ Mr. Bill
"Remember "Pro" is only a name, it's not always a mindset determined to do everything correctly" ~ Mr. Bill
check exchanger for sure