PDA

View Full Version : hvac people


nuclearlemon
10-26-2011, 06:32 PM
sometime during the day, my home furnace stopped working. the fan kicks on, but it's not igniting. do we have any hvac people, or does anyone have any recommendations

Rezarf
10-26-2011, 06:38 PM
The pilot is working correct?

Air Randy
10-26-2011, 06:57 PM
I'm assuming this is natural gas? Have you confirmed your pilot light is lit? If it isn't lit, call me and I can talk you through the lighting process.

If the pilot light refuses to stay lit, the most common failure is the thermistor. This is a copper tube that sticks into the pilot light flame and senses that the pilot flame is burning. Because of this unit, you have to press the gas valve down and hold it for a minute or two when you first light the pilot. Once it heats up enough you can release the gas valve. Release it too soon and the pilot goes out.

This is a safety device so in the event the pilot light goes out it shuts the gas off. They are pretty generic and if you pull yours out (usually very simple) you can buy them at Home Depot, Lowes, etc.

leiniesred
10-26-2011, 07:00 PM
Dirty thermocouple, Ig.
Find the thing that sticks up into the flame. Pull it out, unplug wires, shine it up with your good wire brush and stick it back in.

Randy beat me to it and has a better desc. Of lighting the pilot.

nuclearlemon
10-26-2011, 08:54 PM
thanks for the help. no actual pilot light. i have an hsi setup. reading on the internet and talking to someone, i think my igniter might not be getting hot enough. the guy i talked to is an hvac guy from colo4x4 and i'll call him in the morning with part numbers. he said he may have them in his truck. furnace was working during the day because the house was "warm" when i got home (i keep it set at 54 and it was 53 at 4pm). i've got a space heater for now and the new insulation helps out quite a bit. :thumb:

leiniesred
10-27-2011, 09:24 AM
Ige: My instant on furnace doesn't have a pilot light either, but it still has that thermocouple. My furnace would cycle on, but shut down after about 10 seconds...until I took that thing off and cleaned the carbon off of it. Took about 20 minutes.

Our house was 55 this morning. We haven't turned on the furnace yet this fall. I hope it starts up when we do need it!

SteveH
10-27-2011, 10:27 AM
Ige - my HSI failed to produce enough voltage to fire, and I just helped it out with a propane torch and the furnace immediately lit. The 'assembly' that contained the HSI was $250, but the ignitor piece is $14 online, so I have replaced it a few times with these cheapie ones and they last ~5 years or so before acting up. Some of those HSIs are suppose to produce 1v when hot, and 0v when cold, and you can test them with a VOM and a blowtorch.

Red_Chili
10-27-2011, 10:36 AM
Ignitors are a common failure. Should be able to find one either online or at a local appliance parts store.

60wag
10-27-2011, 10:41 AM
My furnace has a hot ceramic element to light the gas rather than a pilot. The original design lasted several years then failed (cracked). The new design is much more stout and has lasted 15 years - although I now keep a spare on hand should it fail.

When the first one failed, it was -10F outside and the house was geeting cold. The furnace would try to start but would time out when the igniter failed to light the gas. About midnight I tried another idea. I wrapped the igniter with a loop of fine gauge steel wire. The wire acted like a fuse but before it melted, it turned white hot and lit the gas. Once the furnace was running, the igniter wasn't needed anymore. The loop of wire had turned into some drips of steel. I kept the furnace running all night and was able to get a replacement igniter the next day. YRMV

PhatFJ
10-27-2011, 12:34 PM
Ige: My instant on furnace doesn't have a pilot light either, but it still has that thermocouple. My furnace would cycle on, but shut down after about 10 seconds...until I took that thing off and cleaned the carbon off of it. Took about 20 minutes.

Our house was 55 this morning. We haven't turned on the furnace yet this fall. I hope it starts up when we do need it!


X-2 :thumb:

nuclearlemon
10-28-2011, 07:02 PM
i have heat again!!! don at square one hvac in littleton walked me through testing all the different components and got me going! it was either the tube to the pressure switch plugged, or loose plugs on the motherboard, but either way, it is working. this guy literally spent a good 45 minutes on the phone with me explaining how it all worked and how to test everything....on his own time! the shop was closed, he was at home with his kids!

i definitely recommend these guys if you need anything done. btw, they were referred to me by someone who's furnace went out on a -12 degree night and while don couldn't get out to fix it, he did the same thing, walked my friend through diagnostics and told him what needed to be replaced.

http://www.square1hvac.com/

Uncle Ben
10-28-2011, 07:06 PM
i have heat again!!! don at square one hvac in littleton walked me through testing all the different components and got me going! it was either the tube to the pressure switch plugged, or loose plugs on the motherboard, but either way, it is working. this guy literally spent a good 45 minutes on the phone with me explaining how it all worked and how to test everything....on his own time! the shop was closed, he was at home with his kids!

i definitely recommend these guys if you need anything done. btw, they were referred to me by someone who's furnace went out on a -12 degree night and while don couldn't get out to fix it, he did the same thing, walked my friend through diagnostics and told him what needed to be replaced.

http://www.square1hvac.com/


Nice! Give him kudos on our vendor thread so he can be found later!