No heat condition in warehouse

[The Cobbler]

Stopped in to the warehouse earlier this evening, it was cooler than normal . we keep a low set point at 55°. stat was calling for heat in the heat mode. I cycled it off & back on. Unit heater went thru venting, flame ignition and after 10 or so seconds it shut down. repeated 3 or 4 times then shut down . I did get it to run and when I left it was still heating. We have a group of volunteers coming in on Sunday so we will need heat .
I called an HVAC guy I know & left him a message. yet to be returned. I suspect I won't hear from him until Monday .
some google searching & it seems to me that flame sensor probably needs a cleaning. sound reasonable?
what I see online it's usually an easy task ?

should add there is no visible flashing codes , but I didn't get up on a ladder to look closer

 

[dscheidt]

Stopped in to the warehouse earlier this evening, it was cooler than normal . we keep a low set point at 55°. stat was calling for heat in the heat mode. I cycled it off & back on. Unit heater went thru venting, flame ignition and after 10 or so seconds it shut down. repeated 3 or 4 times then shut down . I did get it to run and when I left it was still heating. We have a group of volunteers coming in on Sunday so we will need heat .
I called an HVAC guy I know & left him a message. yet to be returned. I suspect I won't hear from him until Monday .
some google searching & it seems to me that flame sensor probably needs a cleaning. sound reasonable?
what I see online it's usually an easy task ?

should add there is no visible flashing codes , but I didn't get up on a ladder to look closer

That and making sure the flue isn't blocked are reasonable first steps.

 

[T444e]

My guess is flame sensor. Otherwise something is fried on the board. Disclaimer, this is worth what you paid for.

 

[finn]

Flame sensor.

I also ran into that situation when the exhaust of a high efficiency propane furnace became obstructed with fine snow and ice during a storm. Ditched the “bird screen” after that. Same thing happened to my neighbor.

 

[fitter30]

When you either cycle power or turn stat to off posistion then back to heat you just reset the unit and if there is a code it's gone. Someones needs to look at the filters then the burner and control. Flame failure has to to fail three times before lockout. Might also look at gas meter see if if it's locked out from someone not paying the bill.

 

[The Cobbler]

no filters, meter is not shut off.
It was indeed flame sensor . steel wool to the rescue .
and it was a nightmare to get at .
we had to remove the burners & the manifold to get at the bracketry that holds the flame sensor . believe it or not the sensor was screwed in from the inside of the assembly so there was no way to get it out without the major disassembly . it went back together with the flame sensor screwed to the outer of the assembly rather than the inside of it so now it can be reached without having to disassemble. 2 screws & it's out now.

 

[dscheidt]

I suggest you buy a replacement flame sensor, to have on hand if it fails completely.

 

[mm08822]

Buy a hot surface igniter too.

 

[fitter30]

FYI hot surface igniter can glow red and still be be bad. If the burner control doesn't see a minimum amperage it won't open the valve.
Put spare parts in the burner compartment then you don't have to remember where you put them

 

[NUTTSGT]

My guess is flame sensor. Otherwise something is fried on the board. Disclaimer, this is worth what you paid for.

Would it even light and fire if the board was fried ? OP says, he did get it to light.


I would get a lot new flame sensor, since it appears to be the problem, put the new one in and keep the old one as a spare. I'd rather the heat doesn't go back out...

 

[PoorUB]

I remember my mom calling me on blustery winter evening with no heat. Worst part, she is 60 miles away. She was pretty excited and I had to get her calmed down to get her to slow down so I could trouble shoot over the phone. After a few minutes I figured it was the flame sensor and explained to her how to remove it and clean it. We said our goodbyes and I told her to call me back if she needed help or to let me know it was running. She called 20 minutes later, had cleaned the sensor and the furnace was running.

Now she tells people how she fixed her furnace all by herself!

 

[Miss the Pontiacs]

no filters, meter is not shut off.
It was indeed flame sensor . steel wool to the rescue .
and it was a nightmare to get at .
we had to remove the burners & the manifold to get at the bracketry that holds the flame sensor . believe it or not the sensor was screwed in from the inside of the assembly so there was no way to get it out without the major disassembly . it went back together with the flame sensor screwed to the outer of the assembly rather than the inside of it so now it can be reached without having to disassemble. 2 screws & it's out now.

I just knew this would not side track you for too long

 

[The Cobbler]

Buy a hot surface igniter too.

it's spark ignition
and yes, a new flame sensor is in order .

 

[The Cobbler]

I called an HVAC guy I know & left him a message. yet to be returned. I suspect I won't hear from him until Monday .

he did call me back Sat morning and suggested the flame sensor