Nordyne-Intertherm continuous flash

[brandonm_13]

Okay, I don't know the model number, because I just stumbled on to this site, but it is a 2003/2004 mobile home. This problem happened once before, but I dont' remember what the repairman did and I would like to get this fixed myself in case it happens again.

I have the red light flashing. The pilot light won't light. I have a honewell switch(don't know if that matters). I have tried using the instructions on the furnace to get it re lit but to no avail. What should I do?

[Robert]

Hi Brandon,

Will need the furnace model number to help.


Thanks,
Robert

[brandonm_13]

M1MC 090A BW

[Robert]

Hi Brandon,

How many flashes from red led light ?


Thanks,
Robert

[brandonm_13]

It's a continuous blink. The panel says a continuous blink is a fault with the pilot light, which of course there is since there isn't a pilot light on.

[Robert]

Hi Brandon,

Continous flash is a false flame or internal control problem. You don't

have a pilot light, you have an ignitor.


Thanks,
Robert

[brandonm_13]

Well, whatever I have, it isn't working. Does something need to be cleaned or replaced?

[Robert]

Hi Brandon,

You would have to test the circuits through a cycle to see what the problem is.


Could be a bad control or a faulty system component or a safety problem.


First suspect would be the control board as the code suggests.



Thanks,
Robert

[brandonm_13]

Okay. I'm an idiot. It isn't a continuous flash like I thought. I suspected that because it happened once before and I hadn't taken the panel off.

It's actually two flashes. According to the panel, that means a pressure switch is open. I also know that if it was three flashes, that means the pressure switch is closed.

So what is my pressure switch and how do I get it back in the right position?

Thanks again
Brandon

[Robert]

Hi Brandon,

Do you know what the small booster or combustion motor is ?


It will have 4 wires and 1 small tube/hose connected to it.


Follow the tube/hose to the nearby small round disc mounted to

furnace with the 2 tubes/hoses connected and two small wires.



That's the pressure switch.


Make sure the tubes/hoses are clear and not kinked or damaged

and connected/attached securely.


Then make sure the booster motor starts and runs immediately

with a call for heat from t-stat.


If all ok there, booster motor running quietly, then check vent pipe

for any damage or blockage.


Then check and ensure one of the two small wires connected to

pressure switch has 24vac to ground.



IF ALL is ok there, then ~probably~ a bad pressure switch.



Let me know how it goes.


Thanks,
Robert

[brandonm_13]

Well, I have good news and bad news.

First, there is no hum when I try to start the heat. I have checked and the fan and airconditioning settings al work fine.

Since I couldn't find a problem with the pressure switch, I took apart the booster motor and found that a strip of glue came apart and lodged itself between a fan blade and the wall of the pipe, stopping movement of the fan. I have taken the glue out. The fan spins perfectly and does not have any burn marks indicating it is bad, but after replacing everything, I still get the same two flashes.

Now what do I do?

[Robert]

Turn off power at breaker in service panel for a few minutes and restore power and see if it resets itself.


Thanks,
Robert

[brandonm_13]

Wow, I"m stupid. I checked the breaker before I started looking at any of this, but didn't think about it resetting. I will do that when I get home tonight. Thanks.

[brandonm_13]

Well, it was worth a shot, but no go. Looks like it's time to call the repairman.

[Robert]

Hi Brandon,

It may be as you need to know if pressure switch is getting correct water column pressure.



Thanks,
Robert