I'm on the final countdown to replacing my gas valve on my furnace (probably should use a less explosive word than "countdown"!) and the helpful people in this forum who know stuff might be amused at my "Safe Steps" below, but a quicker read option is just to pipe-in on the following two questions:
1. Black Iron pipe or Black Steel pipe for my two pieces out of the valve and out the side of the furnace? One store has steel, the other iron, and both say they are for gas, and they may both be manufactured by "LDR". The pipe inside the furnace looks to be brass (would assume it's not copper) and I'll be replacing the same brass-looking pipe to run to my gas line.
2. The yellow type of Teflon Tape, pipe dope, or an even higher quality of Teflon Tape? I imagine this could venture into just people's preference, but I'm hoping to use teflon tape for all threaded connections (except the "fitted ones" like the shut-off valve and the kinda flexible gas connector line, probably by BrassCraft). At the parts store (gas valve) I'll ask about Red Teflon Tape which the internets shows as a step up from the yellow. Yellow is the best the hardware stores have.
Thanks, and for more amusement or anyone's further consideration, read on below.
Rich
If anyone cares to see the steps I plan to do, I list them here in case there's something dumb that could be caught ahead of time.
Uh, a brief explanation of why I'm doing this: old gas valve's pilot valve is sticking on sometimes
Safe Steps
A. With furnace off (valve turned off inside the furnace, unplugged, gas shut-off valve outside the furnace on gas input line turned to off), turn off water heater (has a standing pilot) and close its gas input shut-off valve as well.
B. Disconnect the pilot tubing from the old gas valve and remove the pilot assembly (as well as its two electric thingies - one like an old soldering iron end that is likely a glow bar for lighting, the other a sensor to make sure the pilot is lit). Of course disconnect each of those two electronically from the Ignition Control (RobertShaw SP 715A) - where one connects to "Ign." and the other to "Sensor"...
C. Sniff pilot gas outlet. Old valve and the gas in-line shut-off both being off makes it super unlikely that there can be an issue with that leaking, but be safe as can be.
D. Pop over to the parts store. Buy the replacement gas valve (RobertShaw 720-070) and hopefully two new pieces (sensor and "glow bar" lighter) to fit into my existing pilot assembly, and possibly a new pilot fitting. I'm thinking now that if replacing anything means the pilot assembly has to be replaced and I cannot use the existing bracket/sheet metal stuff to mount the pilot, I'll likely just clean up mine with some steel wool 'cuz I don't want to get into trying to do sheet metal and bracket type work to put in a new anything there. A sensor and "glow bar" that will work exactly with what I've got? Great, why not. And I reckon I will need new pilot light tubing, but the parts folks will advise me on that.
E. Buy other stuff (black iron/steel pieces for going out the furnace from the new gas valve, BrassCraft flexish piece to run from in-line shut-off valve to black pipe, paranoia terminate plug as described in the next step, better grade Teflon tape than Yellow if available) and return home.
F. Have on hand one valve plug (fitted like connector for BrassCraft gas connector line, but terminates the flow) in case once I remove the gas connector line with the in-line shut-off valve turned off, it turns out the shut-off valve for the furnace leaks. It's not leaking anywhere else, but how do I know if the ball valve isn't actually letting gas through the line since all has been hooked up beyond the valve each time I've had it turned off? Establishing the shut-off is good is something I'll do just with my nose. (This is a plan B to turning off the gas at the meter outside 'cuz that looks like a big to-do, all painted over, etc. I do plan to avail myself of our gas company's service to check out furnaces and gas connections when done, so I'll ask the guy about that meter shut-off and if it should totally work if I need it to, for future disaster reference.)
G. Disconnect old connector line from the in-line shut-off valve. (step F at the ready above if I smell any gas, and that would be to first reconnect, but if gas is leaking thru the closed valve AND my moving the old not-so-flexible-anymore connector line means it too is going to leak, then I have that valve "plug")
H. Disconnect the connector line entirely, then the old gas valve (with straight pipe and elbow pipe still connected to its main input, being aware that in so doing no torque should be applied to the other side - gas pipe to burners - of the old gas valve. Probably just hold the inside-the-furnace main burner gas pipe with a pipe wrench and turn the old gas valve itself, with its input pipe and elbow still attached. Uh, all the wires would already be disconnected and labeled - or colors noted - for reconnecting to the new gas valve...
I. Carefully brush/maybe steel wool the threads of the inside-the-furnace gas pipe that the new gas valve will go onto... Pipe dope was used and have to cleanly get it off of there while keeping the threads in as good of condition as possible.
J. Probably hook up the pilot at this point and some "flashing" that kind of blocks the gas valve from the direct heat of the burners...
K. With Yellow Teflon Tape (or Red if the parts store has that) turn the new gas valve onto the furnace gas line (that goes to burners) - my old gas valve is exactly upside down and I've been told that gas valves function fine any way they end up once tightened onto the threads of the gas pipe going to the burners. Good front access to the on/off lever would be nice, but I don't think I have any control there.
L. Connect a new black iron or black steel pipe piece (mpt each end) that will probably be roughly the same length as the old brass colored pipe piece, probably with an "elbow" (fpt both sides) already connected, as well as an mpt to mpt converter connected to the input end of the elbow. These connections all using the teflon tape, and the one to the gas valve tightened holding the gas valve itself firmly as not to put any torque on the outtake side already connected.
M. Connect the new BrassCraft connector between the in-line gas input shut-off valve and the mpt sticking out from the elbow. Not sure if both of these will be "no teflon tape or pipe dope", but I think at least the connector to the shut-off valve is fitted, and those fitted connections don't use teflon tape or pipe dope.
N. All wires back on to the proper ignition control terminals from the pilot lighter and heat sensor, as well as the wires to the new gas valve terminals (which do match the old gas valve terminals).
O. Now the fun part. Furnace still unplugged and new gas valve turned off, open the in-line gas input shut-off valve having my nose twitching like a rabbit's and using my little spray bottle of soapy water (dish soap mixed with water is what I've read) on all the connections up to all but the connection to the gas valve, confirm that nothing is leaking up to there.
P. At the gas valve input pipe connection I'll use soapy water to test, but likely by using a Q-tip (imagine "R" registered trademark symbol here for "Q-tip") to apply the soapy water all around the new gas valve connection. (More control and no overspray - don't want to get soapy water onto much else than the connection point... Probably be wiping off the soapy water with wet rag after each test inside the furnace...)
Q. If all still seems good, then with the thermostat all the way down (already would be), plug in the furnace and turn the new gas valve lever to On, nose a-twitchin'... Of course gas shouldn't be any further to any other connections, so go turn the thermostat up to fire it up and return quickly. (Hmmm... Maybe think "start it up" rather than "fire it up"?)
R. R but Q for Q-tip again? As then I'd check with soapy water the last of the connections in the loop, the main burner pipe out from the gas valve and the pilot line out from the gas valve. (Hmmm... Could do this with the main burner wire off, and just test the pilot connection first without the burners coming on yet? Then if pilot connection is good, do it again but with the main burner wire back on?)
S. Any non-functioning aspects past that - I'll have the multimeter to test for voltage where it should be, etc.
T. Expectation is that then watching regular usage closely (or actually causing it by adjusting the thermostat), all should shut off every time (including the pilot), and turn on every time, pilot first, then burners after a bit.
U. At my "trail wife's" request (we're backpackers - and yes, I think her request is smart, too), once all done I'd probably continue like I have been (use the furnace kind of manually - turning down the thermostat all the way, turn off the gas valve, turn off the shut-off gas valve on the gas to the furnace, and unplug the furnace) overnight as well as during the day when I'm out or at work, and do have the gas company come out when their and my schedule can accommodate, to have them check it all out. If that is something they don't do anymore, then, uh, just watch it closely for a time, do a lot of sniffing, and eventually feel comfortable that I did it right. Oh, and yes, I'd turn on the water heater gas valve and light that standing pilot once all the work was done and I'd verified no gas leaks.
Sorry that turned out so enormous! I almost ran out of the alphabet. I did think this would be just a short number of simple looking steps, but I will be using it myself, and I do like to have a full plan. If anyone does read any of it and spots something that seems iffy, please do let me know.
Thanks,
Rich Apple
1. Black Iron pipe or Black Steel pipe for my two pieces out of the valve and out the side of the furnace? One store has steel, the other iron, and both say they are for gas, and they may both be manufactured by "LDR". The pipe inside the furnace looks to be brass (would assume it's not copper) and I'll be replacing the same brass-looking pipe to run to my gas line.
2. The yellow type of Teflon Tape, pipe dope, or an even higher quality of Teflon Tape? I imagine this could venture into just people's preference, but I'm hoping to use teflon tape for all threaded connections (except the "fitted ones" like the shut-off valve and the kinda flexible gas connector line, probably by BrassCraft). At the parts store (gas valve) I'll ask about Red Teflon Tape which the internets shows as a step up from the yellow. Yellow is the best the hardware stores have.
Thanks, and for more amusement or anyone's further consideration, read on below.
Rich
If anyone cares to see the steps I plan to do, I list them here in case there's something dumb that could be caught ahead of time.
Uh, a brief explanation of why I'm doing this: old gas valve's pilot valve is sticking on sometimes
Safe Steps
A. With furnace off (valve turned off inside the furnace, unplugged, gas shut-off valve outside the furnace on gas input line turned to off), turn off water heater (has a standing pilot) and close its gas input shut-off valve as well.
B. Disconnect the pilot tubing from the old gas valve and remove the pilot assembly (as well as its two electric thingies - one like an old soldering iron end that is likely a glow bar for lighting, the other a sensor to make sure the pilot is lit). Of course disconnect each of those two electronically from the Ignition Control (RobertShaw SP 715A) - where one connects to "Ign." and the other to "Sensor"...
C. Sniff pilot gas outlet. Old valve and the gas in-line shut-off both being off makes it super unlikely that there can be an issue with that leaking, but be safe as can be.
D. Pop over to the parts store. Buy the replacement gas valve (RobertShaw 720-070) and hopefully two new pieces (sensor and "glow bar" lighter) to fit into my existing pilot assembly, and possibly a new pilot fitting. I'm thinking now that if replacing anything means the pilot assembly has to be replaced and I cannot use the existing bracket/sheet metal stuff to mount the pilot, I'll likely just clean up mine with some steel wool 'cuz I don't want to get into trying to do sheet metal and bracket type work to put in a new anything there. A sensor and "glow bar" that will work exactly with what I've got? Great, why not. And I reckon I will need new pilot light tubing, but the parts folks will advise me on that.
E. Buy other stuff (black iron/steel pieces for going out the furnace from the new gas valve, BrassCraft flexish piece to run from in-line shut-off valve to black pipe, paranoia terminate plug as described in the next step, better grade Teflon tape than Yellow if available) and return home.
F. Have on hand one valve plug (fitted like connector for BrassCraft gas connector line, but terminates the flow) in case once I remove the gas connector line with the in-line shut-off valve turned off, it turns out the shut-off valve for the furnace leaks. It's not leaking anywhere else, but how do I know if the ball valve isn't actually letting gas through the line since all has been hooked up beyond the valve each time I've had it turned off? Establishing the shut-off is good is something I'll do just with my nose. (This is a plan B to turning off the gas at the meter outside 'cuz that looks like a big to-do, all painted over, etc. I do plan to avail myself of our gas company's service to check out furnaces and gas connections when done, so I'll ask the guy about that meter shut-off and if it should totally work if I need it to, for future disaster reference.)
G. Disconnect old connector line from the in-line shut-off valve. (step F at the ready above if I smell any gas, and that would be to first reconnect, but if gas is leaking thru the closed valve AND my moving the old not-so-flexible-anymore connector line means it too is going to leak, then I have that valve "plug")
H. Disconnect the connector line entirely, then the old gas valve (with straight pipe and elbow pipe still connected to its main input, being aware that in so doing no torque should be applied to the other side - gas pipe to burners - of the old gas valve. Probably just hold the inside-the-furnace main burner gas pipe with a pipe wrench and turn the old gas valve itself, with its input pipe and elbow still attached. Uh, all the wires would already be disconnected and labeled - or colors noted - for reconnecting to the new gas valve...
I. Carefully brush/maybe steel wool the threads of the inside-the-furnace gas pipe that the new gas valve will go onto... Pipe dope was used and have to cleanly get it off of there while keeping the threads in as good of condition as possible.
J. Probably hook up the pilot at this point and some "flashing" that kind of blocks the gas valve from the direct heat of the burners...
K. With Yellow Teflon Tape (or Red if the parts store has that) turn the new gas valve onto the furnace gas line (that goes to burners) - my old gas valve is exactly upside down and I've been told that gas valves function fine any way they end up once tightened onto the threads of the gas pipe going to the burners. Good front access to the on/off lever would be nice, but I don't think I have any control there.
L. Connect a new black iron or black steel pipe piece (mpt each end) that will probably be roughly the same length as the old brass colored pipe piece, probably with an "elbow" (fpt both sides) already connected, as well as an mpt to mpt converter connected to the input end of the elbow. These connections all using the teflon tape, and the one to the gas valve tightened holding the gas valve itself firmly as not to put any torque on the outtake side already connected.
M. Connect the new BrassCraft connector between the in-line gas input shut-off valve and the mpt sticking out from the elbow. Not sure if both of these will be "no teflon tape or pipe dope", but I think at least the connector to the shut-off valve is fitted, and those fitted connections don't use teflon tape or pipe dope.
N. All wires back on to the proper ignition control terminals from the pilot lighter and heat sensor, as well as the wires to the new gas valve terminals (which do match the old gas valve terminals).
O. Now the fun part. Furnace still unplugged and new gas valve turned off, open the in-line gas input shut-off valve having my nose twitching like a rabbit's and using my little spray bottle of soapy water (dish soap mixed with water is what I've read) on all the connections up to all but the connection to the gas valve, confirm that nothing is leaking up to there.
P. At the gas valve input pipe connection I'll use soapy water to test, but likely by using a Q-tip (imagine "R" registered trademark symbol here for "Q-tip") to apply the soapy water all around the new gas valve connection. (More control and no overspray - don't want to get soapy water onto much else than the connection point... Probably be wiping off the soapy water with wet rag after each test inside the furnace...)
Q. If all still seems good, then with the thermostat all the way down (already would be), plug in the furnace and turn the new gas valve lever to On, nose a-twitchin'... Of course gas shouldn't be any further to any other connections, so go turn the thermostat up to fire it up and return quickly. (Hmmm... Maybe think "start it up" rather than "fire it up"?)
R. R but Q for Q-tip again? As then I'd check with soapy water the last of the connections in the loop, the main burner pipe out from the gas valve and the pilot line out from the gas valve. (Hmmm... Could do this with the main burner wire off, and just test the pilot connection first without the burners coming on yet? Then if pilot connection is good, do it again but with the main burner wire back on?)
S. Any non-functioning aspects past that - I'll have the multimeter to test for voltage where it should be, etc.
T. Expectation is that then watching regular usage closely (or actually causing it by adjusting the thermostat), all should shut off every time (including the pilot), and turn on every time, pilot first, then burners after a bit.
U. At my "trail wife's" request (we're backpackers - and yes, I think her request is smart, too), once all done I'd probably continue like I have been (use the furnace kind of manually - turning down the thermostat all the way, turn off the gas valve, turn off the shut-off gas valve on the gas to the furnace, and unplug the furnace) overnight as well as during the day when I'm out or at work, and do have the gas company come out when their and my schedule can accommodate, to have them check it all out. If that is something they don't do anymore, then, uh, just watch it closely for a time, do a lot of sniffing, and eventually feel comfortable that I did it right. Oh, and yes, I'd turn on the water heater gas valve and light that standing pilot once all the work was done and I'd verified no gas leaks.
Sorry that turned out so enormous! I almost ran out of the alphabet. I did think this would be just a short number of simple looking steps, but I will be using it myself, and I do like to have a full plan. If anyone does read any of it and spots something that seems iffy, please do let me know.
Thanks,
Rich Apple