Can someone explain to me, what it is that makes a pilot stay lit after holding the button in for one minit on my wall furnace. Cus mine won’t stay lit.
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IF your heating unit is a milivolt system, the pilot heats a small thermocouple that creates about 500-750mV current that holds pilot coil open on gas control valve.
If this is not familiar to you CALL A PRO, don't even think about jury rigging any gas appliance
I get it. I should be getting 500 to 750 mV at the valve, or the t-coupl is bad. Good stuff to know. Results at 11:00.
It is most likely the thermocouple that is shot, they go from time to time, as already mentioned, best to have a pro look at it but changing the thermocouple is usually not that tough, they go in gas fireplaces all the time.
Darren
http://www.LDHindustries.com
Appriciated!
How old is your unit? I've been having this problem too for the last couple/few years each fall, and I'm at the point of firing my rig up now too. I've replaced the thermocouple twice: the first time it fired up and I thought, ah, that must have been the problem, the second time I replace the coupler, nada, no change. So last year I by-passed the thermostat and voila! the unit went on. So now I think it is the thermostat or its connections (once I get the thing going, it gets me through the winter). So now I have the thermostat cover off, and will sandpaper all wire connections and make any other cleaning of contacts; that's where I think the problem lies. My wall heater unit is about 12 years old.
This thing has to be at least that old. I'm gonna ckeck the thermocpl first. Its right up front. Thanks for the T-stat tip.
Trigger, I would hold off buying another coupler, what are they, about $20? Clean all your connectionss (removing screws and actually scraping some copper wires). I knew is wasn't the coupler after by-passing the whole system last year. I'm going to see what is up tonight on my end...
Get a new thermocouple, available at Lowes and Home Dump.
Usually labeled Honeywell and costs only a handful of dollars.
Just make sure to get the correct length copper 'tube'.
I always have at least one or two as spares next to the boiler and replace it maybe once a year, but we leave the pilot light lit year round. I replace it when the pilot light dies on its own, which usually is a sign that it needs to be replaced.
While I replace the thermocouple the venturi tubes are removed and boiler cavity vaccuumed out.
Replacing the thermocouple takes maybe 5 minutes.
If the thermocouple looks to be in fair condition it's more than likely it just died. If it looks to be burned up or partially melted the pilot is set too high causing failure. If you need your settings changed and the owners manual isn't explicit or it's a sealed system - time for a pro.
Who ever invented work didn't know how to fish....
Here's more possibilities........you might have some crud in the pilot orifice either resulting in too small of a flame or in a deformed flame.
Either of these conditions can leave the thermocouple bulb insufficiently immersed in flame to heat it sufficiently which means it won't produce sufficient current to hold the main gas valve open.
Never poke at an orifice with a needle to clean it out. Dissasembly is necessary to remove the offense by appropriately gentle means.
Well, there goes my theory; tried lighting mine last night and got a bit frustrated holding that dang pilot light in, only to have it go out. I'm building a house, but little $hit like this burns me up I could take someone's head off if they were in the way.
I don't know, I guess I will go the thermocoupler route again, but on this model they aren't so cheap, and that didn't seem to help the situation last year. Will also try to clean the orifice of the pilot too...you would have thought I would have addressed this problem back in September instead of now when it is getting a bit nippy at night now.
Follow up: I'm a total loser! So I'm getting ready to swap out another thermacoupler (actually have another one, probably a good used one, in my wall furnace compartment). I try lighting the pilot again and see if it will finally stay on when I click over the valve. Duh!!!!!! The valve was in the "on" position all the time, I keep lighting the pilot, and then kept going counterclockwise turning the valve off!!! No wonder it wouldn't stay lit.
I don't know if this is the problem I have been having the last couple years or not, but when spring comes, I turn off the gas valve to the furnace, not necessarily the furnace valve. So six months or whatever later, I try to fire up the furnace by turning on the gas valve again, but not knowing that the furnace valve is still in the on or operating position. So not thinking and/or being dyslexic, I go through what I think is the proper way to light the furnace; turn the valve till I find or feel the indent, push down, then light the pilot, hold in for longer than the recommend minute, keep turning, and then the pilot goes out!
I don't know what finally brought me to finally realizing that I was going the wrong direction. I think it was the "feel" of the length of turn between pilot indent and off and on i.e. the on turn or distance is longer than going from off to pilot indent on the valve. I think what I need to be conscious of next year is turning the dang furnace valve off in addition to the gas valve to the furnace.
I can owner/build my house, but can't light a furnace!
As we get older we get a little dumber every day, the brain it's the first to go.
What always works for me is to leave a record on the furnaces with duct tape and ink pen or scripto, date and what I did. Then when I return next time I know. If I replace a gas valve or motor I write on the furnace so it's always there. Also use a propane tourch to lite so I don't have to wait for thermo to heat up and hold the button.
Clay
I used the propane torch as a lighter, too. I think I destroyed the old thermocouple that way. Now I know not to overheat the dang thing.
-- J.S.
Clay, what? You mean write something down???? ;-) Whoa...
I tell ya, time flies by as ya get older; my impression is that we get "use" to time--a week doesn't seem as long when you're 40 than 10-years-old when you're waiting on the edge of your seat for the second part of a Disney special on the telie the following Sunday.
And I thought I was the only one that would use a propane torch to lite a pilot. When I moved back to where I am living now ten or more years ago and remodeling the place I am living in, got a little tanked up with my uncle at the local pub. We come back up the hill, spark up the torch, and no worries, the pilot goes on the hotwater heater and I can have a proper shower!
What hasn't gone over too well here on this board though is my using a temporary (it's been a year and a half now) gas line using 1/2" PVC pipe, about 100 feet of it. The electrician, also a poster here, that helped me on my new house project thought he smelled gas; like duh I thought, there's 100' of gas line, none of it buried. Fortunately it was a dead dear on the property stinking up the place and not a break in my gas line.