3400-818 runs continous both heat and fan

[DaveH]

Even with thermostat disconnected both heat and fan runs continuously.
Would this be sequencer or can something else cause this?

[Bill]

Hi, Dave

Yes if both fan and heat are running with thermostat in off. Then it most likely is the sequencer
Here is a link to get a replacement one.
http://www.aberdeenhomerepair.com/store ... -sequencer
If you have any problems ordering it give Mark a call and he can help you out.
Thanks,
Bill

[DaveH]

Thanks Bill
I just replaced the sequencer not long ago (2 years I think). Would insulating the base from the furnace increase it's life span?

[Bill]

Hi Dave,
Insulating the furnace is not going to add years to the life of your furnace. What it might do is add efficiency to the the furnace. What i mean is that you are make your air hold more heat or cooling longer with insulation around your duct work. There for you make the air deliver that heating or cooling to the area's where you want it rather than the heat loss from your duct work. i hope this helps you.
Bill

[DaveH]

Thanks Bill
I was talking about insulating the sequencer base from the front of the furnace. I'm not sure what causes a sequencer to fail internally but it's attached right next to the coils so I'd imagine it's subject to some extreme temps.