Furnace won't fire (so no heating) please help troubleshooting

Shachar

Hi,
My furnace won't heat. I tried troubleshooting, here is what happened so far:
Even though thermostats are calling (I have 2 zones), the furnace only sounds a few clicks and squeaks (like it always does before starting to burn and heat) but the fire is not burning after that like usual. Also the fan is not starting up at all. I opened the cover and saw that the pilot flame was out. Not sure why.
I then put the thermostats all the way down (so they are not calling for heat) and manually lighted the pilot flame. The pilot flame is burning all the time now.
Next I set the thermostats to high so they are calling for heat. I can see that the taco valves are opening (because I can move the lever manually easily unlike when they are not calling where the lever is very hard to move)
Pilot flame stays on all the time now, even if I turn off power to the furnace.
However, now when the thermostats are calling for heat, I don't hear the usual clicks and squeaks.
Furnace fire is not burning .only the pilot flame.
Any ideas on what's the next step?

Thanks
Shachar

mattmia2

Some pictures of the overall boiler and especially of the gas valve and burner area would help. If it is a combination gas valve, did you turn it from "pilot" to "on" after you lit the pilot?

Shachar

Thanks for the reply. Yes I did turn it to 'ON' after I lit the pilot and now it stays on. I would take a few pictures and post shortly.
I want to test the voltage like I did before I replaced a defective taco valve which was a year and half ago.
Even though I can move the taco valve lever pretty easily which would suggest the valve is working and open, I still wanted to test the voltage with a multimeter, but forgot how to do so...I did it a year and a half ago. Can you please remind me how to test this (should the power to the furnace be off? what setting should I put the multimeter on...?
I'll take some pics and upload shortly.
Thanks again

JUGHNE

It sounds like you have a hot water boiler with a standing pilot.

But where is the fan you mention?

Shachar

Here are some photos I just took.

Shachar

When I said 'fan' I meant the vent that blows the fumes to the outside. Can you explain what you mean by 'where is the fan'?
Thanks

Shachar

that round black thing (sorry...) with the little switch on it used to make a few clicks before (when it was operating fine and just before it started burning, right after the thermostats called for heat.)
Now I dont hear the clicks.

JUGHNE

Need picture of the vent that blows the fumes to the outside and also picture of where the exhaust pipe on the top of the boiler goes to.

Jamie Hall

That round black thing which makes a few clicks... looks an awful lot to me like an automatic vent damper, not a fan. And they're nothing but trouble, in my opinion. If it doesn't open -- or open all the way -- the burner won't fire. In the first picture, there is a label "hold damper open". If you can figure out what that refers to, and move it to hold the damper open, you may be able to get the burner to fire.

JUGHNE

The flat of the shaft going into the pipe needs to be parallel to the vertical pipe going up.

My guess is that there was an oil burner boiler there and they just used the flue/exhaust pipe from that.

The barometric swing damper, (just above the electric damper) was for the oil burner. IMO, it is stealing the chimney draft from the gas boiler and could be the reason the paint is burned off of the top front panel of the gas diverter section of the boiler.

Still want to see where the exhaust pipe goes.....masonry chimney??

Shachar

The house is from 1998 and I bought it from the original owner. As far as I know there was never an oil burner here. The exhaust pipe goes through a hole in the wall to the outside of the house where there is a fan which is working/spinning when the furnace is burning.

Shachar

I do not have a chimney.
Also,
I tried setting the vent damper to the "hold damper open" position. Then calling for heat. Still nothing.

Shachar

I took a video of this all around the furnace and the area, but it doesnt seem like I can upload mp4 file

Shachar

I don't understand why before I lit the pilot I could hear the clicks from the vent damper and from inside the furnace, but after I lit the pilot, no clicks anymore....what are the odds that BOTH taco valves went bad just now? I want to try testing the voltage for these but don't remember how. I don't want to mess up the multimeter or the valves but not testing properly.

JUGHNE

The outside fan must run before the main burner will fire.

possibly the vent damper has to open before the fan will run.

With the shaft parallel to the pipe and the little switch in the manual on position the fan might start.

Where are you located?

mattmia2

That paint burned off the draft hood makes me think you need to get a professional to look at this before it causes a fire or kills everyone with carbon monoxide poisoning.

Shachar

I'm in Framingham, MA

Shachar

@mattmia2 This has been like this since we bought the house (over 10 years). I had several different professionals coming in for different problems over the years and no one ever said anything is dangerous other than telling me this is old and I should buy a new furnace from them. I also have carbon monoxide alarm very close by in this basement. But you're right, it's always better to be safe than sorry .

Shachar

@JUGHNE , what do you mean by:
"With the shaft parallel to the pipe and the little switch in the manual on position the fan might start."
Which is the shaft and which is the pipe? Also it has been the same for years and still the fan started every time.
I did call a professional, but I said it's not emergency as it's not that cold right now, only a bit at night...Otherwise they charge MUCH more. I figured if I can troubleshoot and if it is something simple and it starts working I can cancel. They will call me tomorrow probably to let me know when they can come.

JUGHNE

You better let them come to check this out.

Ask them if that old barometric damper should be in the exhaust pipe and why the paint is burned off the panel.

pecmsg

With all that discoloring on the front and the pipe I wouldn’t use it.

Shachar

I agree. I will let them come check this out anyway and ask these questions. Thanks for the sound advice.
I want to rule out the possibility of valve malfunctioning.
I have this multimeter, but I forgot how to test the voltage on the valve even though I did this a year and a half ago.
So to test the voltage, where do I connect the red wire, and which settings on the multimeter I should choose. Also, should the power to the furnace be on when I test the voltage? or is it better with the power off...? (the multimeter manual says "Warning: never test continuity on a live circuit")

Shachar

Shachar

OK, now after turning the power off and on multiple times during my troubleshooting, now the furnace doesnt seem to turn on at all. before, when turning on the power there was some click and noise, now it's not even doing that. Maybe the whole things is electrical related. I'll just wait for service to come and figure it out.

Thanks everyone for your responses!!!

Shachar

Update: I was wrong that the furnace does not power on. I switched off the breaker before and forgot to turn it on.
I now understand what was said about the automatic vent damper. I do see that when pilot flame is on, furnace has power, and thermostat calls for heat, the taco valve is opening, and then the shaft in the vent damper shaft turns 90 degrees to the open position(which is parallel to the pipe). I can even see it's open if I peek through the pipe opening at the front. Based on what has been said so far, I assume the next thing that should happen is that the fan which is at the end of the pipe near the ceiling and through the wall to the outside should turn on, but it doesn't turn on. It doesn't seem to be an easy fix to me and I'll wait for the service guy to show up and investigate.
I wanted to add info I didn't say before - the plugged pipe extension used to be where a gas water heater would vent through the same pipe. That water heater died a couple of years ago and I got a powervent water heater which has it's own vent pipe to the outside. The plumber who installed the powervent water heater cut and plugged that pipe extension.
I also don't know the reason why the burn marks on the front panel are present. It was like this when we bought the house (10+ years ago) and did not change since.
I set the thermostats to lowest, turned off power to the furnace and set the pilot knob to off, so it's not burning and no gas is flowing. I have a good wall AC on the first floor of the house and I am using its heating function for the first time (I have the AC for a few years now). It heats both floors pretty good so far, and it's not expected to get too cold outside, so I'll just use this until service arrives.
Thanks again for all the members here with your responses.
I will also update here after the service guy investigates.
Shachar

coby

okay so let us know what the hvac service tech finds. But what I see is your pilot probably went out due to weak thermal couple or dirty pilot orfice (needs maintainence). When you took off the plate to access the pilot and relit, did you put that plate back on before trying to bring on heat? Because if Not it looks like the rollout limit is touching the boiler cabinet. You could have shorted it out, so no power to burner if that is the case. Also nothing wrong with barometric damper, they are great for controlling draft and combustion if set up properly. Highly recommend on any appliance in the same CAZ. So do not remove make sure it is set to -.02 draft for good combustion. Will need to have a Qualified tech that can check combustion and draft. Good luck and let us know what they find.

SuperTech

It sounds like the Field Controls power vent motor is shot. Those motors need to be oiled annually. Most home owners and a surprising amount of techs don't know this.

Shachar

Service guy was here. They sent a young guy who did the troubleshooting over the phone with someone more knowledgeable. He said that 24 volt isn't coming to the gas valve and the reason is that the Aqua Stat is bad and need to be replaced. He also said that I need to replace 'backflow' and 'feeder' and thermocouple and it's not guaranteed that it will fix the issue even after that. He kept trying to sell me a new boiler as mine is old and bad. I said I will consider my options. I'll get another service guy. I hope next one is more decent.

Edited out the prices and monetary related text. Sorry, I didn't know it's not allowed. I initially put it to add context.

mattmia2

Talking price is not allowed here. Please edit to remove prices.

Not knowing why there isn't 24v to the valve is a red flag, if it is solidly not there, finding were it stops is pretty basic troubleshooting. the way things are overheating is alarming, but someone who knows what they are doing will know how to tell if that is the result of a condition that has been corrected or a current condition and will be able to adjust it and tell you if they have the combustion and draft correct or there is a problem that can't be corrected.

Try the "find a contractor" at the top, there are many contractors in MA.

Shachar

hi @mattmia2 , Sorry, but I did not understand what you meant when you said
"the way things are overheating is alarming..."
What do you believe is overheating?

mattmia2

the paint burned off of the draft hood. it shouldn't get that hot if it is drafting properly.

Shachar

Hi @mattmia2 . The paint did not burn. this is soot that I guess leaked out and this was like this before I bought the house. and I can clean it to see the paint still fine and not burnt underneath.

Shachar

mattmia2

It shouldn't be spilling out like that either. Or really producing soot if it is gas.

Jamie Hall

@Shachar -- that technician's comments are right up there with "Sorry lady, but the triple encabulator is shot and we'll have to replace it and the override whanger. That will be [big bucks]".

Find another tech.

I'm betting on the end switch on the motorized damper.

Shachar

I had another tech showing up and after 10 mins they found that the outside fan receives 120V (I think that's what they said) but is not starting and is likely the issue, as the gas won't start to flow unless fan is already running. @mattmia2 like you said, they followed the flow to see where it stops.
They'll quote me for the outside fan. This seems more logical to me, even though I'm not a professional. The process was always damper opening, then outside fan starting to run, then gas flows and burns.
About the soot, I really don't know where or how it came to be, but for the past 12 years this has not changed, so whatever happened to cause this was before that.

Shachar

@Jamie Hall
https://www.youtube.com/watch?v=Ac7G7xOG2Ag

Jamie Hall

I love it! How does he do it with a straight face?

Shachar

because he knows what he's talking about...Full text:

"For a number of years now, work has been proceeding in order to bring perfection to the crudely conceived idea of a transmission that would not only supply inverse reactive current for use in unilateral phase detractors, but would also be capable of automatically synchronizing cardinal grammeters. Such an instrument is the turbo encabulator.

Now basically the only new principle involved is that instead of power being generated by the relative motion of conductors and fluxes, it is produced by the modial interaction of magneto-reluctance and capacitive diractance.

The original machine had a base plate of pre-famulated amulite surmounted by a malleable logarithmic casing in such a way that the two spurving bearings were in a direct line with the panametric fan. The latter consisted simply of six hydrocoptic marzlevanes, so fitted to the ambifacient lunar waneshaft that side fumbling was effectively prevented.

The main winding was of the normal lotus-o-delta type placed in panendermic semi-boloid slots of the stator, every seventh conductor being connected by a non-reversible tremie pipe to the differential girdle spring on the “up” end of the grammeters.

The turbo-encabulator has now reached a high level of development, and it’s being successfully used in the operation of novertrunnions. Moreover, whenever a forescent skor motion is required, it may also be employed in conjunction with a drawn reciprocation dingle arm, to reduce sinusoidal repleneration."

Shachar

coming back to my heating issue (sorry for the off topic comic relief). So it seems that the outside power vent motor isn't running. I guess it's also a good idea to replace this corroded part (feeder?) in the middle of the picture. Can any tell me what this part is called?
Also about the power vent motor, it should be enough to replace just the motor, and not the whole assembly (motor+wheel+control etc), right?

Shachar