So we woke up this morning with two problems.
The Internet was out
The Furnace was out
My wife was on her way to a social work seminar of some sort and needed the Internet to get directions
She kindly didn't wake me up, but grew increasingly irritated with her attempts to get Internet access first on her school Mac school Laptop, then on her ( the one I stole) Linux laptop, then finally on my linux desktop. She finally woke me up when she got desperate about the time she had to get there.
The wireless router was unplugged.
mapquest a route.
write down the Left - Right turns to arrive there.
By the way, it's 50 degrees in the house, the furnace won't come on
30 year old furnace in a 150 year old house.
Me with chronic anemia, heart palpitations and a broken hip replacement.
Short of breath after walking 30 feet.
Call the HVAC people, right?
Minimum $200 bucks.
At least lets figure out what's wrong
Reset the furnace circuit breaker- check
turn off the thermostat- check
Now comes the good part
Hobble out to the cellar door access, lift the 75 lb door, hobble down the steps
sit by the furnace and catch my breath
turn off the power at the furnace
change furnace filter
Hobble back up the stairs and set the thermostat to give heat
sit down and pant
answer phone call from wife
I attempt to give directions in terms of spatial conception of the roads and north, south east west
she needs Left right turns and landmarks
I google where she is going
use street level views to describe to her landmarks and left right and in between turns
I take a percocet (available to me only because I have a hip that is roughly like stabbing myself with an icepick every time I flex it)
I hobble outside and back down the steps to the furnace.
I turn on the power
The furnace begins it's heat cycle
The ignitor starts to glow- check
the ignitor heat sensor kicks open the gas valve- check
the burner lights, flames are blue, symmetrical, and travel the length of the burner-check
flame sensor heats up - gas valve remains “locks” open, igniter goes off - check
High temperature limit switch in combustion chamber kicks on the blower fan -check
Furnace burns evenly, correctly for about 5 minutes- then shuts down.
Turn off power to furnace
Turn power back on
Ignition cycle starts again
Burner lights- and goes off.
Turn off power to furnace
Climb back up stairs and go inside
Practice deep breathing
Take another percocet ( I'm allowed 2 at a time, as needed- I felt it was needed)
The Furnace is a Central Environmental Systems (Sears Roebuck) PBKM-LD16N12OE
I call the local HVAC store
$89 for the service call- ( which is a bargain, believe me)
My sense of the way things work tells me that what is happening is that the High Temperature limit switch, which controls the fan and monitors the temperature of the heat exchanger, is kicking out, shutting down the furnace.
This could be because :
1) The sensor is 30 years old and has failed
2) The heat exchanger actually is overheating,leading to a meltdown and a furnace fire.
I speak to a technician - he can't guarantee what it will cost naturally, and can't get out until tomorrow-if I'm willing to pay double time for a Sunday call. He warns me that such a situation is very dangerous, and that he would have to “Red Line” ( shut off) my gas service (leaving me without a cooking stove as well) until it is corrected. He warns me that it is against the law to disable safety devices on a furnace and I could face fines and imprisonment if I were to say, simply wire around the high temperature limit switch.
I thank him and hang up
I just went down to the cellar and “hot Wired” the high Temp limit switch
Just got back up and finished my “blow” break
The furnace is running, the house is warm.
The percocet has kicked in
When I get a little more energy, I'll go down in the basement and take the switch out and go to the hardware and buy a replacement.
Meanwhile, I'll just sit here and wait for the cops to show up to arrest me for furnace tampering
Isn't common sense government wonderful?