Any HVAC Specialists in the house?

[KShine]

First time trying to use the heat this year (electronic-ignition furnace), and it just isn't firing up. It goes through the 3 attempts and then switches off. The igniter lights up, but no flame whatsoever (and yes, the gas is switched on).

[anolian]

I am no HVAC specialist put I had exact same problem last year. And ur turned out there was s sensor in the furance that was dirty. Got it cleaned and works as usual now.

[Ed Mack]

I'm not a HVAC tech, but I had a similar issue. There is a flame sensor by the igniter that sometimes gets dirty or goes bad. If the unit doesn't sense a flame, it shuts down the unit. It also could be a stuck gas valve. Maybe tap it a couple of times. Finally, it could be a bad computer board. Just a few issues I have had over the years.

[exciter1]

I'm not a HVAC tech, but I had a similar issue. There is a flame sensor by the igniter that sometimes gets dirty or goes bad. If the unit doesn't sense a flame, it shuts down the unit. It also could be a stuck gas valve. Maybe tap it a couple of times. Finally, it could be a bad computer board. Just a few issues I have had over the years.

 

I've had the same issue. I had to clean the flame sensor periodically. On mine, it was actually a pin in front of the flame jets that would get some carbon build-up on it from time-to-time.  I had to wipe it off with a brillo pad.

[sadowsk1]

My only suggestion is use Angie's list to find the best guy in town, make an appointment instead of having to make an emergency call on a night or weekend to evade crazy charges, and if your instincts tell you not to do something, don't go for it.  

[anolian]

For me i have an annual maintenance contract with my gas company its like $14 a month this includes 2 maintenance  a year one for furnace one for AC and if there is a problem they come with in 24 hours and they cover the cost of all parts used. I found out furnace maintenance and parts can really add up for the maintenance contract is worth its weight in gold.

[exciter1]

Here is an crude image showing the general area where most flame sensors are found.

[KShine]

Thanks for the responses. I have had the sensor issue before (where it needed cleaning), but in this case it isn't flaming up at all. I heard something about air sometimes getting in the line, but I'm not so sure.

 

I certainly won't be messing around with it too much  - I just like to have an idea before someone comes in to fix it.

 

We have separate heat upstairs, and gas fireplaces on the 1st floor and basement - so at least heat won't be a problem.

[Huskers1236]

Thanks for the responses. I have had the sensor issue before (where it needed cleaning), but in this case it isn't flaming up at all. I heard something about air sometimes getting in the line, but I'm not so sure.

 

I certainly won't be messing around with it too much  - I just like to have an idea before someone comes in to fix it.

 

We have separate heat upstairs, and gas fireplaces on the 1st floor and basement - so at least heat won't be a problem.

Starter fluid and a match.  I guarantee you'll get a flame. 

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Disclaimer:  Don't actually try this at home, kids.

[ISO8T0]

post a pic of your furnace. (like exciter did) theres enough DIY homeowners on here to help you out.

[KShine]

Having trouble adding the photos, but I might be figuring something out (no, not the lighter fluid idea). This furnace uses a smart valve. It appears that the igniter/heat sensor work a bit different on these. The older ones would light up as normal (full flame), and if the heat sensor failed, it would turn off. These appear to have a very small, pilot light sized flame (before the full flame) - so maybe it can still be the heat sensor. 

[ISO8T0]

you could try putting a flame under the heat sensor and see if that will trigger the sensor to open the vavle.

[romoore245]

I am HVAC trained but not a lot of field experience. Working towards the office side. However the little bit of field work I did, I saw this a couple of times and the suggestions given other than the lighter fluid are pretty good. I did come across a couple instances that the gas company had lowered the gas pressure to the house during the warm months and then the igniter wouldn't acknowledge the amount of pressure.

 

I do recall the igniter is a cheap part and easy to change but costly for a service call. There is a few forums dedicated to DIY of this nature, this is one that's not so but you may be able to get a few more suggestions http://hvac-talk.com/vbb/ if you have any more specifics I can try to look up some suggestions.

[barbos]

Remove the sensor / igniter and make sure it's not broken. I had that problem two years ago. Cant find a picture of it, but every winter I had to clean it, a new dollar bill will work just like sand paper.

[KShine]

Thanks again all - I believe that it is that the Flame sensor needs cleaning. I was thrown at first by the Smart Valve, as it seems to use a small preliminary flame that tests the sensor (my last furnace went full flame right away). I just need to find the right tool to unscrew what I believe will free the sensor for cleaning (it is squeezed back there pretty good). I will hopefully get to it later today, but I will update people when I do.