Burner Issues

[JohnnyO]

I recently picked up a used single-tier, three burner rig. It's awesome. I've been wanting a single tier rig for years to make brew days easier. When I get it going, it cranks! It has KAB4 burners, individual shutoff valves and dials along with the regulator at the tank.

I have a lot of problems getting the burners going though. I'll get ignition, but the flames quickly go out. The seller said that I have to barely open the regulator at first so that it gets lit. However, I haven't had any luck. Tried replacing the regulator with a new high pressure regulator, but that didn't work. Was thinking that maybe it needed a low pressure regulator, but everything I read on here says that shouldn't be the fix.

Aside from contacting a plumber, what can I do?

 

[Brewsader1]

Have you cleaned out the burner heads really good? You can get some silt buildup that could clog or mess up the propane getting through.

 

[JohnnyO]

I will break down the system and try this, but the same issue happens with every burner, so I think it's a different issue.

 

[Brewsader1]

Fair point. When you open up the valve to the tank as well as the valve to a burner, can you hear/smell the gas? Like are you sure you’re getting a good flow?

Also, when you’re lighting the burner, is the kettle on or off the stand?

The way I see it, your issue is either a lack of oxygen or a lack of LPG. An excess of oxygen would just give you a yellow flame and an excess of LPG may not get lit but it sound like you’re eliminating that possibility with how you’ve tried it thus far.

You may want to clean out the oxygen intake as well, but like you said, it’s an issue on all of them.

 

[JohnnyO]

Thanks for the perspective. I am going to have to break it down and see if there is something impacting the flow. I was pretty sure I'd have to do this anyway as the steel piping is rusting, and I'd feel safer replacing it.

 

[day_trippr]

It appears you have a green ACME coupling nut for the propane cylinder. Inside every ACME nut is a spring-loaded ball that serves as the "Excess Flow Preventer" valve which is supposed to kick in if there's a breach downstream of the cylinder.

However, the EFP can activate if the cylinder valve is suddenly opened when the regulator is already open. When the EFP trips the flow will be reduced often to the point it won't support combustion; other times you may notice the burner is still running but at obviously low power. It will stay that way until the gas is shut off and then the downstream pressure is fully relieved (at which point you may hear a metallic "ping" as the ball goes back to its sprung stop).

So...the key is to avoid a sudden flow of gas from the cylinder. Thus the recommended start sequence is as follows:
- shut off everything
- slowly open the cylinder valve, let the pressure equalize, then open the cylinder a couple more turns.
- THEN slowly open your regulator, then open a needle valve to one of the burners, and get that one running.
- repeat the last step for each burner you need running.

Beyond all that...be aware running three bg14s on a single BBQ tank is likely going to be problematic if high power is needed as the cylinder may not be able to keep up with the demand. As the vapor is drawn off the remaining liquid propane gets colder and colder to the point it's not actually able to generate enough vapor and the whole thing may ice up. Dunking the tank in water can often help get through the day.

Also, there is an alternative to an ACME coupled regulator: a POL style, which doesn't have an EFP. It's what I use on my rig for a pair of bg14s...
Cheers!