HVAC/furnace repair

[clayton86]

Anyone on here knowledgeable about hvac specifically furnace pressure switches? 
 

Our furnace stopped working a little while back like right when the cold weather was starting to hit us here in WNY. Been watching YouTube videos about diagnosing what’s wrong since I don’t want to pay some crazy amount of money to have a technician come out and tell us it needs a simple part and charge us like 10x as much. So I’ve done a bunch of tests and I’m pretty sure my pressure switch is bad. When the furnace started acting up I could tap on the switch with my knife or pliers and it would kick on and run for a while. Some times a week then a a few days then a few hours of that. It will run if I bypass it also just jump the two connections taking out the switch it runs but I gotta go down and take the jump off when it cycles off because it reached temp otherwise it just blows air with no heat since it won’t light unless I manually jump it when needed. 
 

So how do I know what switch to buy to replace it. I’ve searched for it by the numbers on the label and I get like 10 different switches even when I put in the long part number. Ranging from $30-$150 I mean I’m all for buying the cheap one but it looks like the WC rating is what’s different mine is 0.94”WC for the Honeywell P22. So will one close to that rating work? 
 

Any help would be greatly appreciated especially since our electric bill jumped $800 this last month with electric heat only since our house has both gas and electric heat. 

[12poundbass]

I’m too far removed from the HVAC trade to be much help, but from what I remember, there were plenty of times I would take the hoses off to find a white powder inside that would interrupt (if you will) the proper functioning of the pressure switch. I’d clean that out by gently blowing or sucking on it. You have to be very careful when doing this, because the diaphragm in the pressure switch is VERY fragile! 

[gim]

56 minutes ago, clayton86 said:

Been watching YouTube videos about diagnosing what’s wrong since I don’t want to pay some crazy amount of money to have a technician come out and tell us it needs a simple part and charge us like 10x as much.

Usually there isn't a ridiculous charge to come and just diagnose the problem.  Once they find the problem, its definitely worth getting a second opinion/estimate though, especially if they try to tell you that you need to pay an overly high amount to replace something.

 

You're already paying through the roof for electric heat while trying to fix the problem.  I wouldn't go much longer on that though.  At some point you're just spending more on replacement electric heat than you would to hire someone to fix the furnace.

[Tennessee Boy]

There's always ebay.

 

https://www.ebay.com/itm/134413893515

[slonezp]

36 minutes ago, 12poundbass said:

I’m too far removed from the HVAC trade to be much help, but from what I remember, there were plenty of times I would take the hoses off to find a white powder inside that would interrupt (if you will) the proper functioning of the pressure switch. I’d clean that out by gently blowing or sucking on it. You have to be very careful when doing this, because the diaphragm in the pressure switch is VERY fragile! 

Tell me more about blowing and sucking...

You will more than likely destroy the switch doing that so I wouldn't recommend it

 

 

I'm a havc parts distributor. Your switch is obsolete. Sounds like the switch is bad based on what you're saying. It could be other issues as well. There are universal switches available. The issue becomes are you measuring +.94"wc or -.94"wc. Generally, it is -"wc if that's coming off the inducer motor.

Robertshaw makes an adjustable switch but it has a different mount than what you have and different electrical connections. Your switch is a SPST and the adjustable is SPDT. It will work, you just need half a brain to install it and to set the "wc

Part#2374-495

Post the model/serial# of the furnace and I can see if the part has been replaced with something else

[clayton86]

22 minutes ago, slonezp said:

Tell me more about blowing and sucking...

You will more than likely destroy the switch doing that so I wouldn't recommend it

 

 

I'm a havc parts distributor. Your switch is obsolete. Sounds like the switch is bad based on what you're saying. It could be other issues as well. There are universal switches available. The issue becomes are you measuring +.94"wc or -.94"wc. Generally, it is -"wc if that's coming off the inducer motor.

Robertshaw makes an adjustable switch but it has a different mount than what you have and different electrical connections. Your switch is a SPST and the adjustable is SPDT. It will work, you just need half a brain to install it and to set the "wc

Part#2374-495

Post the model/serial# of the furnace and I can see if the part has been replaced with something else

It’s a Trane XR90 I don’t see a serial # on it but it’s the XR90 at least that’s the badge on the one door

[slonezp]

m/s# will be inside the furnace, on a tag either in the burner or blower compartment

[clayton86]

5 minutes ago, slonezp said:

m/s# will be inside the furnace, on a tag either in the burner or blower compartment

M# TIX1B060A9361AB

S# 6482PCA7G

date of manufacture 11/2006

[Woody B]

I'm tight, and I'm an avid do it yourselfer.  I installed my own (electric) heat pump.  However,  you're messing with gas.  There's several things that could potentially go wrong, especially with a 16-17 year old system.  I'd bite the bullet and call a professional.  

 

(I don't know anything about a gas furnace)  

 

Sorry, I'm sure this isn't what you wanted to hear.  

[slonezp]

Sent you a PM

1 hour ago, Woody B said:

I'm tight, and I'm an avid do it yourselfer.  I installed my own (electric) heat pump.  However,  you're messing with gas.  There's several things that could potentially go wrong, especially with a 16-17 year old system.  I'd bite the bullet and call a professional.  

 

(I don't know anything about a gas furnace)  

 

Sorry, I'm sure this isn't what you wanted to hear.  

That pressure switch has noting to do with gas. It measures static pressure from the inducer motor. It's primary purpose is to confirm operation of the motor and that there are no blockages in the flue or heat exchanger. While I do agree that the system, being as old as it is, should be checked by a professional, he's not going to blow himself up.

 

The pressure switch went out on my furnace on New Years Eve. It was almost 20 years old as well. 

[clayton86]

When we bought the house 3 years ago the previous owner had records of everything they had checked and serviced every year. The furnace was one of them there’s a sticker on the side of it where it’s been signed off by the tech that came and checked it over and changed the filter every year. 
 

bought the house in 2020 it was built in 1820 so it’s a old solid built house. The previous owner was a lawyer and the old police chief of the town so he had $$$ the roof was done in ‘18 water tanks(2 of em) were swapped 07/09 so they are fairly current I suppose. The furnace was new back on 07 I think it said it was installed. All the upkeep on the house was documented and done but they did nothing to update the house looks wise just the necessities roof, furnace, gas fireplace, electric heaters in the addition, hot water tanks, basement ect. But it was still rocking the old shag carpet in some rooms and ugly floral wall paper haha. 

[12poundbass]

1 hour ago, slonezp said:

he's not going to blow himself up

I can attest to this. I was checking inlet and outlet pressure on a gas valve one time and forgot to put the plug back in. I fired up the furnace, saw the plug glow, heard the gas valve open, heard the hissing sound, followed by a fireball coming at me. Who needs coffee in the morning when you have a fireball come at you and the smell of burnt hair. ?

 

I actually did that twice! 

[TnRiver46]

5 minutes ago, 12poundbass said:

I can attest to this. I was checking inlet and outlet pressure on a gas valve one time and forgot to put the plug back in. I fired up the furnace, saw the plug glow, heard the gas valve open, heard the hissing sound, followed by a fireball coming at me. Who needs coffee in the morning when you have a fireball come at you and the smell of burnt hair. ?

 

I actually did that twice! 

Hahahahahah. Yikes 

[12poundbass]

Just now, TnRiver46 said:

Hahahahahah. Yikes 

Nah, too many safety features to keep anything bad from happening. 
 

Fuel oil furnaces, now those you can make into a bomb if you don’t know what you’re doing. I never cared for those. 

[Jigfishn10]

10 minutes ago, 12poundbass said:

I can attest to this. I was checking inlet and outlet pressure on a gas valve one time and forgot to put the plug back in. I fired up the furnace, saw the plug glow, heard the gas valve open, heard the hissing sound, followed by a fireball coming at me. Who needs coffee in the morning when you have a fireball come at you and the smell of burnt hair. ?

 

I actually did that twice! 

HAHAHA!

 

Wait, you have hair?  

[12poundbass]

1 minute ago, Jigfishn10 said:

HAHAHA!

 

Wait, you have hair?  

20 years ago I did. 

[TnRiver46]

I would have soiled my linens 

[slonezp]

9 hours ago, TnRiver46 said:

I would have soiled my linens 

Want to talk about soiled linens? When I was still turning wrenches, I went on a call that a warehouse unit heater wasn't working. I was standing on a pallet on a forklift 20ft in the air. Had the guy cycle the unit from the thermostat and I hear the gas come on and the ignitor comes on. Generally, a proper operating unit would fire in under a second or 2. The unit fires up after about 8 seconds or so and blows up in my face. Burned off my eyebrows and a bunch of hair. What had happened is one of the forklift drivers hit the unit heater and jacked up the gas train. The gas train filled the cabinet with gas rather than the heat exchanger and BOOM! I'm lucky I wasn't blown off the pallet to fall 20ft to my death.

[Jigfishn10]

14 hours ago, slonezp said:

Want to talk about soiled linens? When I was still turning wrenches, I went on a call that a warehouse unit heater wasn't working. I was standing on a pallet on a forklift 20ft in the air. Had the guy cycle the unit from the thermostat and I hear the gas come on and the ignitor comes on. Generally, a proper operating unit would fire in under a second or 2. The unit fires up after about 8 seconds or so and blows up in my face. Burned off my eyebrows and a bunch of hair. What had happened is one of the forklift drivers hit the unit heater and jacked up the gas train. The gas train filled the cabinet with gas rather than the heat exchanger and BOOM! I'm lucky I wasn't blown off the pallet to fall 20ft to my death.

If you were on my job, when you got down, I would have asked how you are and if you're alright. Once confirmed, I would have thrown your AZZ off the job .

Didn't you take your OSHA 10 or 30? You know better than to stand on a pallet lifted by a forklift?

[12poundbass]

24 minutes ago, Jigfishn10 said:

If you were on my job, when you got down, I would have asked how you are and if you're alright. Once confirmed, I would have thrown your AZZ off the job .

Didn't you take your OSHA 10 or 30? You know better than to stand on a pallet lifted by a forklift?

[slonezp]

2 hours ago, Jigfishn10 said:

If you were on my job, when you got down, I would have asked how you are and if you're alright. Once confirmed, I would have thrown your AZZ off the job .

Didn't you take your OSHA 10 or 30? You know better than to stand on a pallet lifted by a forklift?

This was early in my career prior to taking all the OSHA courses. When one does things repeatedly without incident, one becomes complacent. Complacency can kill.