My furnace broke down and it's been 2-20 degrees Fahrenheit for a couple of days. The house was down to 50 F. I narrowed it down to the pressure switch. This switch needs to be open before a heating cycle will start, but close for it to run. It's backordered locally for a month, and will take 2 days to ship here.
I found a relay with a 5v coil voltage, so I soldered it to some wires on the load side and connected it where the switch had been. I soldered a USB cord on the coil side. I connected that to a phone charger block, and plugged it in to a smart plug.
The plug is programmed so that when it senses its been off for 1 minute it turns on for 20. If I'm right this should allow the furnace to cycle for 20 at a time every 21 minutes if the thermostat is calling for heat. It seems to be working so far. The house is up to 65. 🤞
Are you sure the pressure switch itself is the problem & not an obstruction in your flue pipe? Please check for the safety of you & your family.
I've checked the switch for continuity as I applied air pressure and engaged the switch. The switch is audible. Continuity is spotty and low or non-existent. I will definitely consider the flue and check it when I get home, though. Thank you. I also have a CO detector, which has remained silent.
Always wise to have a CO detector near gas equipment.
The switch has a tiny hole that allows the ambient side feel ambient pressure. This tiny hole can get clogged with rust. Clear it with a tiny drill bit or awl. I was pretty happy when I figured that out on a winter Sunday.
Hey friend, I checked the flue just now and it's happily blowing stream a couple feet away from the house. I feel good about it, but I do much appreciate your looking out for me.
I've given those switches a few solid knocks with the handle of a screwdriver & they will work temporarily. You could try that if your redneck engineering isn't working consistently.
I did try that, wondering if it was misaligned or hung up in there. No dice. Good to know it works sometimes, though. I do this fancy thing at work to save IVs where the nurse has poked all the way through the vein. I tell new nurses that 50% of the time it works every time. I figure it's like that.
As for the temporary fix, it works like a charm. I'll have the new part tomorrow, anyway.
For someone with the same furnace, thank you for helping me understand what to look out for, also OP, dope
Very good!
Update: my house was apparently not toasty when I called from work to check. The d@mn dogs ripped the flap off their doggie door and it wouldn't shut properly! Am I doomed to be cold? I told the kids to put the blocking panel in it (duh) and just let them in asked out with the door. Ya know, pretend not to be a bunch of lazy beggars. I kludged that too, once I got home. The house is toasty. The dogs are happy. I'm going to have a beer and probably do my laundry. What a week!
You’re doing this with dogs in the house? Man loves a gamble
Bonus if you used any sort of tape or wire to hold it together
No, just solder.
A truly proper redneck engineer!
I have but one upvote to give, but it is yours.
Pretty clever. I’m assuming you are a nurse from your comments and normally I may say you are in the wrong line of work but we need healthcare professionals. Good temp fix.
Thanks. Yes, I'm a nurse by trade, but a very general tinkerer in my spare time. I've got the new switch in there now, all operating as it should. This just got me through the couple of days it took to get the part, and it worked really well!
Damn nice!
No Kings...or proper electrical work either for that matter.
The sub isn't "beautifulengineering".
This was a very temporary solution that's saving me hundreds of dollars in broken pipes and HVAC company fees. I need it to last for 24 hours more, that's all. I'm a big fan of "do it right or call someone", but I can repair or build almost anything. And I'm meticulous when I have the resources. Look back through my profile and find some of my plumbing work.
Dude, he's keeping his house warm by rednecking a replacement part that he can't get. No call for that kinda rudeness.