Day & Night 395CAV - Question about the draft safeguard switch

[mhermes]

My furnace is either Bryant, Day & Night, or Payne. It is definitely model# 395CAV042091 Series E. It says "Plus 80" on front. Manufactured in 1995.

It had been working fine until today 3-Dec-2006. It stopped working. The component test works as expected (exhaust fan, igniter, blower). When the call for heat signal comes in, the exhuast fan turns on but the igniter, gas, and blower do not. After a short amount of time the status LED blinks a code 31.

I'm getting a status code of 31 - Pressure, draft safeguard switch or (some other) limiting switch (which my model does not have). After spending a lot of time checking all connections, waiting for presumed reset delays, and trial and error I disconnected the draft safeguard switch and got the same status code. As a test, I pulled both wires off of this switch and connected them together - shorted the wires together bypassing the switch. The furnace then worked fine. I suspect that this switch is bad.

Two questions:

1. Is it correct to assume that the draft safeguard switch is bad given the above information?

2. If so, how do I figure out where to buy a replacement switch? Using Google turned up a lot of hits but none of them dealt with buying a replacement switch.

Any advice would be appreciated.

[gasguy]

First- It is not correct to 'assume' anything when dealing with a safety device that is meant to protect the lives of everyone in the building. Maybe the switch is doing what it's supposed to do and shutting the furnace down because there is a problem! Call a pro to check it out.

Second- This is not a DIY site. Please read the forum rules.

[mark beiser]

That switch should be a manual reset type switch that most likely has done its job and shut the furnace down due to a potentially very dangerous problem with your furnace, or the venting for the furnace.
The switch itself failing on its own is the least likely possibility.

You need to shut it down and call a pro.

[hvaclover]

You jumped out a safety?????

Not cool, man.

Could have gotten major CO inna house .

[mhermes]

Originally posted by mark beiser
That switch should be a manual reset type switch that most likely has done its job and shut the furnace down due to a potentially very dangerous problem with your furnace, or the venting for the furnace.
The switch itself failing on its own is the least likely possibility.

You need to shut it down and call a pro.

Thanks for that useful information Mark. I did end up shutting it down and have a pro coming to the house tomorrow.

[travistee]

I usually just check out the other pro site. Why would you give out this info and sale your brother short.

Shame on you!!

OP your questions and answers are correct. Change out all parts you mentioned, and I would include changing out the hx. Though if you change the hx, make sure you get a good seal on the idm and hx or you could have a np and things could go boom and burn the structure down.

Better call a pro

[markj]

I have worked on many of these over the years. Although I have found this switch tripped many times I do no recall ever replacing a defective one. They usually trip for a reason.
Good that you shut it down and called a pro. Let us know what he finds.
Also ask this question...Do I have or do I need a flue liner.
Best of luck

[markj]

[QUOTE]Originally posted by travistee
[B]I usually just check out the other pro site. Why would you give out this info and sale your brother short.

Shame on you!!

Who/what are you upset with? I did not see anything out of line here. Do you wish to clarify?