HVAC nightmare...the sequel

[Freezing]

I have hobbled a long way from my last post thanks to this community. Back in March I had some issues that I have finally got around to fixing bringing me to my current issues.

Link to old problems: homerepairforum.com/forum/hvac/8836-hvac-nightmare.html

Briefly back in March: I had what was believed to be a rollout on this packaged unit that melted wires and caused shorts entitled "nightmare." The vent or inducer motor was discovered locked up as well.

So far I have replaced all melted wires, inducer motor and fan blade, and roll out switch. I do still have a suspect faulty control board

Current Symptoms:
AC: When using the AC the blower motor never stops, I have to go and flip the breaker to the unit then flip it back on and the blower motor will not start again until I turn the ac on again, but still continues to run after off command is given. Yesterday after tinkering with it for hours it is cycling right again and the blower fan will shut off after the AC is given off command. Now it is working right after messing with it yesterday, but it was doing this before so I suspect it will do it again.
Heat: When I give it the heat command I hear one click....brief pause....inducer motor kicks on and runs, but does nothing else. I never hear the igniter or smell any gas coming out of the unit.

Questions:
1. What parts sound suspect on the AC side that will cause it not to shut the blower motor off after the thermostat is set to off.?
2. What should the heat side do after heat command and inducer/vent motor starts? Gas/Ignition spark?
3. The black wire from the inducer/vent motor is not used if using the red wire? Note 2 on diagram states to use black for 208v operation.

[paul52446m]

I have hobbled a long way from my last post thanks to this community. Back in March I had some issues that I have finally got around to fixing bringing me to my current issues.

Link to old problems: homerepairforum.com/forum/hvac/8836-hvac-nightmare.html

Briefly back in March: I had what was believed to be a rollout on this packaged unit that melted wires and caused shorts entitled "nightmare." The vent or inducer motor was discovered locked up as well.

So far I have replaced all melted wires, inducer motor and fan blade, and roll out switch. I do still have a suspect faulty control board

Current Symptoms:
AC: When using the AC the blower motor never stops, I have to go and flip the breaker to the unit then flip it back on and the blower motor will not start again until I turn the ac on again, but still continues to run after off command is given. Yesterday after tinkering with it for hours it is cycling right again and the blower fan will shut off after the AC is given off command. Now it is working right after messing with it yesterday, but it was doing this before so I suspect it will do it again.
Heat: When I give it the heat command I hear one click....brief pause....inducer motor kicks on and runs, but does nothing else. I never hear the igniter or smell any gas coming out of the unit.

Questions:
1. What parts sound suspect on the AC side that will cause it not to shut the blower motor off after the thermostat is set to off.?
2. What should the heat side do after heat command and inducer/vent motor starts? Gas/Ignition spark?
3. The black wire from the inducer/vent motor is not used if using the red wire? Note 2 on diagram states to use black for 208v operation.

1. You have a fan relay which would be in your electronic board, if you have a electronic board, If not you still have a fan relay, and it could be sticking because of bad points.
2. I don't have your wiring any more, but after vent motor get up to speed, you either have a end switch in that vent motor that has to make or you have a pressure switch that has to make so then you get spark and gas.
3. If you have 240 volt power then use the red wire. If you changed the transformer you have to make sure the are wired right. some are made for both 240 and 208 power. later paul

[Freezing]

Paul, thanks again for the information.

1. I have had cars with fan relays act the same way. Thanks for letting me know the control board does have car-like fan relays on it.

2. The new vent motor came with a new motion switch that is integrated onto the top of it, so I will assume for now it is providing the correct information to the control board. I guess I need to look at the "smart valve?", which I found it on youtube (skip to 2:11) (youtube watch?v=C1vdUZO52f0). My guess is the smart valve is not so smart anymore given the melting it has sustained to the housing from the suspected rollout. Again, all that happens upon Heat call is click...brief pause...then the vent motor runs and runs and runs.

3. Thanks for confirmation on the red wire; just wanted to make sure I was reading the diagram correctly.

[paul52446m]

Paul, thanks again for the information.

1. I have had cars with fan relays act the same way. Thanks for letting me know the control board does have car-like fan relays on it.

2. The new vent motor came with a new motion switch that is integrated onto the top of it, so I will assume for now it is providing the correct information to the control board. I guess I need to look at the "smart valve?", which I found it on youtube (skip to 2:11) (youtube.com/watch?v=C1vdUZO52f0). My guess is the smart valve is not so smart anymore given the melting it has sustained to the housing from the suspected rollout. Again, all that happens upon Heat call is click...brief pause...then the vent motor runs and runs and runs.

3. Thanks for confirmation on the red wire; just wanted to make sure I was reading the diagram correctly.

watch the plug in connections on the smart valve. They some times push the wire out when you plug them in, and that made a lose or open connection.
later paul