fault codes for heating system

[w1ljm]

Hi,
I have a Cenrurion heating system Model #gf9s060b12up11j that stopped producing heat. I inspected the unit to find that it is giving a fault code of 3 red flashes. The chart on the cover states that the fault condition is: pressure switch stuck open. Could someone tell me what the pressure switch is, that it is referencing to? where it is located, and how to inspect it? The unit kind of looks something like this one in the link http://www.energysavingsusa.net/catalog/item/1603486/1397681.htm
Thank, Frank

 

[Jimbo]

You need the manual for your unit, but it sound like it has a draft inducer blower. These types have a pressure switch to ensure the blower is operating correctly and proper draft is induced, before it allows the gas burner to come on, as this could lead to fatalities in the home. It is a critical function, and should be checked by a qualified technician.



As an aside, this type of thing is the reason that ALL homes with ANY fuel burning appliance should have one or more carbon monoxide detectors installed.

 

[Sponsor]

 

[Jadnashua]

A hole in the ductwork or an obstruction that upsets the air flow to the burner could cause that. It could be just a bad switch, too. Or, the fan might not be turning.

 

[lextech]

I believe Centurion is made by York. So you should be able to get another manual from a York distributor.

The pressure switch is located in the cabinet usually near the induced draft motor. You will find at least 1 flexible (rubber) hose (it looks like automotive vacuum hose) connected to it. This hose is usually black or red/orange, but I have seen gray, anyway there will be at least 2 wires connected to switch also.
When the thermostat calls for heat the board on the furnace will check to see that this switch is in its normal unpowered position (normally open or closed) if the switch is not in this position the board will not allow the ignition sequence to continue as the switch is telling the board there is sufficient induced draft when none should exist. That's not a problem if the unit isn't fired, but what if you had a plugged flue and the switch told the board that everything was fine when it really wasn't? This would be a CO issue! That's why the board stops the ignition sequence. Most likely the switch is bad or you have a wiring issue ie: loose wire, corroded terminal, burnt or broken wire. There are ways to trick the switch and make the unit fire, but I wouldn't recommend trying this without proper training.
Call a reputable service company and have them check the unit out. Heck, if it hasn't had a maintenance check in a while make that part of your service call and maybe the service tech can clean and adjust your furnace and make it a little more efficient.

 

[Jadnashua]

My old boiler did this once, and it was the plastic pipe of the concentric closed combustion system had cracked. They eventually ended up with a recall and switched the interior pipe to SS. The thing may be doing it's job - preventing combustion because the air movement isn't correct. If you have really deep snow, or possibly the outlet is iced up, that could cause it as well. There may not be anything physically wrong with the boiler - it could be with the vent/air supply. the schematics and manual should guide you to determine what is wrong if you can read and interpret them and have a multimeter. If not, it's time for a pro.