coleman 3400A818

[Georgess]

Started to not blow as hot as it used to. Is it possible coils are not getting full volt/amperage?
What would cause this to happen?

[Robert]

Hi,

Bad sequencer, limit or heating element usually.


Test left end spade terminal of element coil to ground for 120vac.

Do same on right end.

Do this for each coil with t-stat set to call for heat after about 45 seconds.


Left sides should read 120vac if sequencer and t-stat is good.

Right side should read 120vac is limits and breakers are good.


Thanks,
Robert

[Georgess]

Thanks for the information, it helps. Is there a way to test sensors and sequencer when disconnected from furnace?

[Robert]

Hi,

Limits should always be closed, so remove and ohm across the terminals to see if they are closed or open.

They should only open when overheating occurs and then close again once cooled back down.


Sequencer can be tested by ohming across top and middle terminals to see if open.

Then ohm across bottom to see if it is closed.


IF those two are ok, then apply 24vac to bottom terminals, power wire to one side (front) and neutral /common to the other (back).

Then, with 24vac applied to bottom coil terminals, wait about 45 seconds and then ohm the top and middle again.

They should now be closed.



Thanks,
Robert