'DREAM garage' + 1850's vintage house = ?

[HoleshotHolset]

Thanks, dudes. I'm glad I have ya'all for support like this.



Jim - you went out of your way to help me and I really appreciate it.



I still haven't been able to get that furnace running... at least now I know that the gas is turned on, though. I cracked open the line that used to feed the range... the gas is definitely flowin'. I may need a referral for a good furnace mechanic pretty quickly... it's bound to get cold soon.



You want pics?... I've got a few... it ain't much to look at, but it's solid. I posted a picture of the furnace, since it's giving me the most grief right now.



BTW, those bricks on the front are real... but they're painted so they look kinda ghetto and out of place.



Matt

 

[daveshoe]

furnace 101

looks like a high effecency furnace there. When these things start up, the following should occur,in this order. 1-the exhaust or forced draft will run. 2-After the sensor switch determines that a forced draft is occuring, the spark ignition will emit a series of sparks ora glow igniter will turn on[glowing red]. 3After the furnace detects the igniter is on,the gas pilot will light. 4 once the gas pilot is lit,and the furnace detects a hot enough flame,the main burner will light.

If the furnace has been idle for a while, take the ignition assembly out and clean the orifice on the pilot light . Also clean the thermocouple with alch ohol,do not touch it with your fingers ,and re-install. I have to baby-sit my gas boiler like this at least once a year to keep it going

Go through this process and observe things. Post here and mabey we can talk you through it.

Oh, I forgot. Make sure there is voltage present at the furnace. If someone shut it down ,they might have cut power to it or removed a fuse right on the feed wire to the unit. You may want to crack the gas line at the furnace to get ''new'' gas there at the furnace. A shut-down could leave you with a lean gas condition that takes forever to work through the small pilot light. Once you do this,tighten the joint,soap the joint to check for leaks,and try to fire it after you are sure no strong odor of gas is present

 

[HoleshotHolset]

Hey Dave,



Yeah - folks keep telling me that it's a high efficiency unit. But, right about now... it's 0% efficient. You're description of what should happen is very helpful.



The forced draft motor is running and the ignitor is firing... but no flames. So it shuts down after it gives up on the pilot. This furnace has been idle since winter... and is pretty dirty...



Should I hear the gas valve click to start the pilot? I haven't been able to hear the valve do much of anything... . It's getting 24VAC in two places when all of this is happening. I was under the impression that the ignitor was on a 10 second delay...



Thanks for the tips/advice,



Matt

 

[Champane Flight]

Gas valve

It might be the gas valve control not opening. Make sure you turn off the gas before removing.

 

[MFalkinham]

Matt, I'm just curious. Were you aware when you made the offer on this house that the furnace wasn't working? If so, that should have been something that the previous owner had to fix prior to closing. If not, an offer contingent on having an independant home inspector evaluate the property would have caught it. You then could have used this as a bargaining chip to get the price down some more.



For $300 my home inspector found a laundry list of problems that we had the previous owner fix prior to purchase, and then my attorney saved me even more money when some additional problems occured during the closing (you did hire an attorney, right?). Just some friendly advice for your next home purchase.



- Mike

 

[jdkenyon]

I don't know if this is related or not, but on my parent's furnace there is a U shaped trap on the drain with a vent a little higher up. If the furnace has been setting for a while sometimes you have to add some water through the vent so it seals the trap and then the furnace will light up. Otherwise it does exactly what yours is doing.

 

[HoleshotHolset]

It might be the gas valve control not opening.

Yeah, I've been wondering that for a long time. But I'm not sure if you'll hear a big click/pop for the pilot like you'd hear when the solenoid for the main burner kicks on...

Were you aware when you made the offer on this house that the furnace wasn't working?

This house was a foreclosure and was sold as-is...

... on my parent's furnace there is a U shaped trap on the drain...

Are you talking about the condensation drain from the A/C evaporator?



I'm going to try cleaning out the pilot light tonight and see where that gets me. I forgot to ask this last night - where should I try to bleed some gas off? About the only place that I can see is the sediment 'trap' on the gas feed below the shutoff valve... Could I loosen the pilot light tube that goes into the combustion box?



This is one thing that I don't want to BOMB, but at the same time want to learn how to fix myself...



Matt

 

[jdkenyon]

I believe this is a drain for the main burner unit. I guess part of being high efficiency it will create large amounts of moisture and that is why there is a drain. Their previous furnace wasn't designed properly and rusted out because of all the moisture.

 

[HoleshotHolset]

JD,



That would be great if I could make my furnace run just by adding water... I'll look for a trap or vent tonight while I'm in there cleaning out the pilot.



Matt

 

[Paychk]

Hey Matt



I don't see as well as I used to, but the main gas shutoff in the line looks to be off. If I'm seeing right, the handle looks to be turned so its at a 90 to the centerline of the pipe. If it is, the handle should be inline with the centerline of the gas pipe, that is the on position.

 

[HoleshotHolset]

Hi Alan,



That picture is old... I took it when Tisdale and I were walking through the place looking for issues. That valve is now in the ON position.



I got the pilot light to work tonight! I took the flame sensor/pilot light right out of the furnace and checked it over... I had a hard time blowing through it, but it got progressively better... so I stuffed it back in there.



I took the pilot tube off the gas valve and turned the (electric) switch on/off really quickly and had gas at the pilot tube... so then I put it all back together and had a working pilot light. The ignitor kept trying to light the pilot even though it was lit... the sparks aren't frequent or powerful, but they're still happening. Scot said it's the flame sensor. Makes sense, too... if the flame sensor isn't 'seeing' the flame... then it will keep trying to ignite it.



I didn't think to write down any numbers - so I'll have to go there tomorrow night and get 'em so that I can get a new flame sensor/pilot.



Interesting stuff... I've always been interested in HVAC - now I'm a shadetree technician (barely)!



Matt

 

[Batman]

Hay Matt, congrats on the purchase!





Best of luck!

 

[HoleshotHolset]

Thanks, George... I'm gonna need all the luck that I can get! :-laf



Matt

 

[daveshoe]

Hi Alan,



That picture is old... I took it when Tisdale and I were walking through the place looking for issues. That valve is now in the ON position.



I got the pilot light to work tonight! I took the flame sensor/pilot light right out of the furnace and checked it over... I had a hard time blowing through it, but it got progressively better... so I stuffed it back in there.



I took the pilot tube off the gas valve and turned the (electric) switch on/off really quickly and had gas at the pilot tube... so then I put it all back together and had a working pilot light. The ignitor kept trying to light the pilot even though it was lit... the sparks aren't frequent or powerful, but they're still happening. Scot said it's the flame sensor. Makes sense, too... if the flame sensor isn't 'seeing' the flame... then it will keep trying to ignite it.



I didn't think to write down any numbers - so I'll have to go there tomorrow night and get 'em so that I can get a new flame sensor/pilot.



Interesting stuff... I've always been interested in HVAC - now I'm a shadetree technician (barely)!



Matt

Sounds like the pilot orifice is still partially plugged. Strong enough to light the pilot,but too weak to be hot or bright enough to trip the main burner. My pilot sends a flame to a probe that is thermal[thermocouple]The thermocouple generates a small amount of electricity which opens the main gas valve. If your pilot is still a little dirty,the electrical signal is too weak to get the job done. Take a small wire from an extension cord to clean the crud from the orifice[the tiny hole at the flame end of the pilot tube. There could also be spider webs in the pilot tube . Use brake cleaner and compressed air to clean it up. Make sure you clean up the thermocouple where the flame contacts it. [last statement does not apply to optical device that takes place of thermocouple. in that case,clean the window of the optical device. ]

A furnace tech can do a much better job than this guessing game stuff I posted. He can check voltage and knows if parts are weak and need replacement. Don't blow yourself up or burn your house down!

EDIT;You should also check for oil ports on your blower and also the tiny forced draft blower that forces the exhaust out the chimney .

 

[HoleshotHolset]

Sorry... I should have updated this last night...



We have ignition! I did what Scot said - shorted out the yellow and white wires going into the gas valve after the pilot came on and wah-lah... instant presto magic - big flames!



I picked up a brandy new pilot assembly today which also includes the flame sensor. Due to the fact that this thing is sorta old and of a funky design (circa 1988) - parts ain't cheap. $92 for the thing... I could have ordered it online for like $83, but it's getting cold out these days. To add insult to injury they offered to have someone come out and make me a quote on a totally new furnace/AC system. I declined... for now. :-laf



I tried messing with the pilot adjustment on the gas valve last night after I had it all up and running (hot wired) and it didn't do much of anything... so the orifice is probably plugged up with poo of some kind. The new pilot/flame sensor assembly should take care of that... until it gets clogged with poo. At least I'll have the old one as a spare if I can clean it out, etc.



Dave, between you and Scot's internet HVAC diagnosis - I've learned a LOT about my furnace and will probably be able to get it all squared away. I can't thank you guys enough...



Wish me luck with the new pilot/flame sensor tonight.



Matt - Go modern. Go gas. Go boom.

 

[HoleshotHolset]

I put the new pilot/flame sensor in last night.



Instant presto magic - the thing fired right up the way it should.



The pilot flame was MUCH bigger than anything I ever had with the old pilot... so the orifice was probably plugged. I'll keep the old one as a backup and clean out the orifice...



BUT, I think I have an issue with the wall thermostat. Once the room came up to temperature and kicked the furnace off... I saw the mercury switch (with the round Honeywell thermostat cover removed... ) tilt back to the left and turn the furnace back on less than two minutes after it shutdown.



So - that's not good. I'm going to go look at electronic thermostats after work... hopefully I can find one that's not a 'voltage hog'. I've read about issues where some electronic thermostats can cause issues...



Matt

 

[Batman]

Matt, I had picked up an electronic unit from Home Cheapo when I first bought my house. It has timers built in to save fuel, turns the heat up and down as I program it. cost around $100.



HTH

George

 

[daveshoe]

Keep us posted on whether a new t-stat helps your short cycle problem. I had a new furnace that ''hated'' the old mercury honeywell. Problem solved after eloctronic model installed.

 

[HoleshotHolset]

I picked up a digital/programmable t-stat last night.



I was looking at them for about 5 minutes and was ready to walk out until I saw one that looked pretty neat. I ended up with a Hunter Auto$aver®™ Model #: 44550 Click here for more info, if you care. It's Energy Star compliant... and even more so when you set it at 55°F in the winter!



I really dig the backlight... other than that... it was comparable to other t-stats on the market with a few exceptions. The one I really like is called "Energy Monitor". By hitting one button... you can see how much 'runtime' your furnace has had in the last day/week/month/total. I thought that was pretty cool.



After doing some armchair programming and installing it... the furnace cranked on... came up to temperature and shutdown. The time between shutdown and the next time it fired up was still pretty short... probably 10 minutes or so... but it was WAY better than it was before with the old Honeywell bi-metallic spring/mercury switch t-stat.



I also bought a digital thermometer with a memory that will allow you to recall the high/low temps... I figure that's a good way to see how well the whole system's working... especially since I'm not moved in yet.



I've fought a few battles with this HVAC system and it seems I'm winning the war. Luckily, I didn't have to use any WOMD. :-laf



Thanks for the help/advice/encouragement, folks...



Matt

 

[ropinfool2]

I installed the same T-stat in my house and RV. Works great. On your old t-stat, the anticipator was probably misadjusted. This does what it says, anticipates when the furnace is needed. Those old mercury switches were pretty reliable. Good luck. Wish I was close, I love to help people with that kind of stuff, especially when there is free beer involved, :-laf (but hate working on my own stuff), used to work for the gas company as a service tech. , we repaired anything that used gas. Good luck! John