Jotul GF3 BV - pilot won't stay lit, tried everything I can think of

[hoopsta1423]

Hi all,

I've got a Jotul GF3 BV ((broken link removed to https://jotul.com/us/guides/_attachment/12843?_download=true&_ts=13e1dae4cc4)) that I'm having trouble with. It's used (new to me last year) and I did have similar issues getting it going last year, but it eventually did start up. Unfortunately I don't recall exactly what the issue was because I tried everything (nothing worked), walked away from it for a week, tried it again and it started without hesitation...

Here are some things I've tried:

Thermopile - ~500mv after holding the pilot for ~1min (with stat off). I get the same reading with old and new thermopiles. When I switch the fireplace on, this drops to ~200-220mv (this tells me the thermocouple magnet is working correctly)

Thermocouple - ~14mv while holding the pilot

Gas valve - resistance across TH and TP is ~2.4 R which I've read falls in line with where SIT 820 valves should be. Thermocouple magnet test is <0.2 R, again falling in line with what it should be (AFAIK). (https://www.mygasfireplacerepair.com/2013/11/how-to-test-your-main-control-valve/)

Pilot light is strong and blue when I'm holding in the gas control knob (see photos attached). As soon as I let go, it dies (no matter how long I was holding it for).

I've taken pipecleaners to all gas lines/orifices and haven't found any cobwebs

All the readings above were taken with the front glass removed. I have also tried keeping the front glass on and haven't had any luck. The only other thing I can think of that I haven't tested is the snap discs. This fireplace has a couple of them (I believe) but as far as I'm aware, a bad snap disc wouldn't keep the pilot from lighting, it just wouldn't allow the main burner to turn on.

Any and all help would be greatly appreciated
Thanks!

 

[DAKSY]

Thermocouple - ~14mv while holding the pilot!
That's your answer. Your TC should read more that DOUBLE that.

 

[hoopsta1423]

Thermocouple - ~14mv while holding the pilot!
That's your answer. Your TC should read more that DOUBLE that.

So I was able to get it started again. Just took it all apart and put it all back together....

Regarding the TC, do you happen to know where to get a replacement? I tried one listed but it was too short, can't seem to find the longer style

 

[DAKSY]

Your local Jotul dealer should have one.
You can also call Best Fire in Troy NY &
have it shipped to you for a fee...
Make sure you have the serial number off the rating plate.
(518) 687-2387

 

[hoopsta1423]

Your local Jotul dealer should have one.
You can also call Best Fire in Troy NY &
have it shipped to you for a fee...
Make sure you have the serial number off the rating plate.
(518) 687-2387

Great thanks,

Any ideas as to why this works sometimes and not others? Can a thermocouple really be that finicky? I'm afraid to turn it off to retest the TC voltage because I'm not sure I would be able to get it going again. It's really hit or miss

 

[DAKSY]

A TC should be generating 25 - 34 mV, enough to hold electromagnets in the valve open.
If yours is holding at 14mV, maybe the magnets are starting to fail - just a guess.
Get the correct replacement TC from a dealer, if a universal type doesn't work (or fit),
& you should be all set.

 

[hoopsta1423]

A TC should be generating 25 - 34 mV, enough to hold electromagnets in the valve open.
If yours is holding at 14mV, maybe the magnets are starting to fail - just a guess.
Get the correct replacement TC from a dealer, if a universal type doesn't work (or fit),
& you should be all set.

So if I have similar issues with a new TC, it's reasonable to assume the valve should be replaced?

 

[DAKSY]

Bad valves are rare. VERY rare. Get the TC in there & enjoy the heat.

 

[sticks]

I believe that unit has a vent safety switch. It could be bad. Or sometimes those wires get pretty crispy

 

[hoopsta1423]

Well my pilot light went out this morning - not sure why but it's pretty windy so it's possible that a very strong gust caused a draft and blew it out. Tried for 30mins to get the pilot back on, but couldn't. So I replaced the TC with a new one that I had ordered, but still can't get the pilot to stay on. New TC holding at 18.5mV

Any ideas?

 

[hoopsta1423]

I believe that unit has a vent safety switch. It could be bad. Or sometimes those wires get pretty crispy

Yea, I'd heard of that, but jumping that vent switch doesn't solve the problem unfortunately

 

[hoopsta1423]

A TC should be generating 25 - 34 mV, enough to hold electromagnets in the valve open.
If yours is holding at 14mV, maybe the magnets are starting to fail - just a guess.
Get the correct replacement TC from a dealer, if a universal type doesn't work (or fit),
& you should be all set.

Re-reading this now, is it really possible that my new TC is bad? What are the odds?

 

[DAKSY]

Not being condescending here, but how are you reading the TC output?
You need to remove the fitting from the valve.
One Probe of the multimeter on the VERY end that
came out of the valve & the other one on the copper sheathing.
Depress the pilot knob, light the pilot HOLD the
knob in to fuel the pilot...NOW take a reading.
Unless you're using alligator clips on your multimeter,
you need three hands...

 

[hoopsta1423]

Not being condescending here, but how are you reading the TC output?
You need to remove the fitting from the valve.
One Probe of the multimeter on the VERY end that
came out of the valve & the other one on the copper sheathing.
Depress the pilot knob, light the pilot HOLD the
knob in to fuel the pilot...NOW take a reading.
Unless you're using alligator clips on your multimeter,
you need three hands...

Appreciate it. Yes that's exactly what I am doing. Fitting removed, alligator clips, holding pilot for ~1-2 mins, don't need 3 hands

I honestly think I got a bad TC, waiting on another to arrive

 

[DAKSY]

OK. Let us know how you make out...

 

[hoopsta1423]

OK. Let us know how you make out...

just bad luck...new TC works like a charm

 

[hoopsta1423]

And....I'm back....

Stove worked like a charm all winter. I turned it off and disconnected it for a couple weeks to do some work to our hearth. Finished that up, reconnected the stove and problems popped up again

1st attempt - pilot stayed on, but the whole stove shut down just a few seconds after turning the gas on (pilot too)

2nd attempt - same as first. pilot would light, but when i turned the gas on for heat, the stove would shut down after ~5 seconds

Every attempt since then - pilot will not stay lit

TC/TP Readings are both good (30mv/550mv). I've taken the whole thing apart and tried blowing/vacuumming out any cobwebs that may have appeared in those 2 weeks. There is no noticeable change in the pilot flames when I am trying to light it. I've tried tapping the regulator to see if something is stuck in there

At this point, I'm completely confused. With the issues I had prior to the winter and similar issues now, I have to think that something is wrong with the valve.

Any additional thoughts?

 

[DAKSY]

Where did you use the air?
Just around the pilot assembly?
Did you pull the burner & the burner orifice?
That's where the spiders build their nests.
Compressed air doesn't always work on that area.
It will blow the nest out of the way, & when
the gas starts to flow it'll blow back into position.
You'll need a Q-Tip or a pipe cleaner to swirl around
in the gas tube behind the orifice.
One other thing I'd look for & that's the high temperature
snap disk, which can fail & the wiring to & from it.
The sheathing can be compromised over the years
& the copper core can short out to the stove body.
Let us know what you find.

 

[hoopsta1423]

Where did you use the air?
Just around the pilot assembly?
Did you pull the burner & the burner orifice?
That's where the spiders build their nests.
Compressed air doesn't always work on that area.
It will blow the nest out of the way, & when
the gas starts to flow it'll blow back into position.
You'll need a Q-Tip or a pipe cleaner to swirl around
in the gas tube behind the orifice.
One other thing I'd look for & that's the high temperature
snap disk, which can fail & the wiring to & from it.
The sheathing can be compromised over the years
& the copper core can short out to the stove body.
Let us know what you find.

Air everywhere, through the pilot tube/orifice, through the burner tube/orifice. Blowing both ways to try dislodging anything that may have gotten stuck. I took a pipe cleaner to every spot that I could too.

I did try jumping the spill switch with no luck, but there is another snap disk in the back that I can try jumping. The wiring to the switches appears to be in good condition from afar

I've got another TP/TC on the way because why not.

 

[hoopsta1423]

Just to update...

Just installed brand new TC but pilot still won't stay on

I'm completely stumped

 

[DAKSY]

Check the milliVolt output on that TC

 

[hoopsta1423]

Check the milliVolt output on that TC

~21mV

 

[DAKSY]

Not good enough. You want to see a TC generate around 28mV.

 

[hoopsta1423]

It's brand new! And the one it replaced was doing 30mV but the pilot still wasn't staying on. That's why I'm stumped and thinking it's got to be the valve.

 

[DAKSY]

Take a plastic handled screwdriver &
give the valve a couple of sharp raps.
You don't hafta bash it, just rap it.
The electromagnets for gas flow to the
pilot hood may be stuck. If that doesn't work,
I guess your valve may be the culprit.
Until last winter I had only seen ONE gas
valve fail. Then I saw two in two weeks.
Both on 9 year-old Regency U39s...