Chattering LP gas valve

MikeG

I originally posted under controls what I thought was an igniter issue. I thought this a better category now that I looked at it closer. This a Burham LP boiler. On a call the igniter lights the pilot and the burners light. A few times some of the burners did not all light in succession. From the start of the call and continuing when firing the gas valve has loud vibrating chatter. It runs until the call is satisfied or hits high limit. All wires are good and grounds cleaned and checked. 3 wires to the valve mv, mv/pv, and pv. Voltage from mv to ground and pv to ground is 23.3-23.6 v. Is this a low gas pressure issue, bad valve, dirty valve? Waiting to get pressure checked. Tank is full. Thanks. Mike

Ironman

I doubt it’s the valve, though it could be.

The burners not properly igniting suggest a separate issue.

You really need a competent tech that understands gas and the controls on site.

You have a potentially dangerous situation and should get a pro out immediately rather than attempting to repair it yourself.

MikeG

Ironman,
I just checked the simple things. I know what I don’t know. It’s a nine burner boiler. The igniter will light the burners, sometimes the 4 to the left farthest along the manifold light first, and there is a longer delay on the remaining 5. That is an intermittent situation, but obviously something not right. Just trying to understand the chattering as a symptom of something. It’s in my sons house and we have a tech scheduled. Thanks. Mike

EBEBRATT-Ed

Sounds like it could be two problems.

There is a chanell the gas has to travel across as it ignites (travel tube) so the ignitor only lights 1 burner usually and the flame travels horizontally parallel to the front of the boiler to light the other burners. Usually fixed by removing and cleaning and checking the alignment of the burners.

if your getting constant voltage at the gas valve and it chatters it sounds like a bad valve

MikeG

Thanks. We try to do the simple easy checks and maint. I will relook cleaning the burner tubes and orfices. My son cleaned them as he does every season, but I will redo. As far as voltage, when it is running the voltage stays 23.3-23.6 checked with 2 different multimeters. If it’s a bad valve I’ll have it replaced. Thanks mike

Ironman

Cleaning involves removing the burners and washing them with hot water and then blowing them out with compressed air, not just vacuuming them.

If you’re using a DMM, it may not respond quickly enough to show a 60hz fluctuation in voltage. I’ve seen a bad ignition module cause what you’re experiencing.

MikeG

We can easily reclean them. I’ll have to ask him if he just blew them out. I used 2 different digital multimeters. I’ll have to get my analog one out. That would mean the control board could be the issue which is where the ignition cable is connected. It does fire and run but just chatters constantly. Does voltage need to be more than 24 v? Thanks. Mike

JUGHNE

How full is the LP tank?

EBEBRATT-Ed

@MikeG

if your getting 23.3 volts with a load on the transformer (boiler firing) you should be ok. If your getting 23.3 with no load and it drops down with a load that could be an issue.

22 or below is a problem. Voltage variations should be less than 10% in your case 2.4 volts

MikeG

Tank is full. 23.3-23.6 v is when the boiler is firing.

EdTheHeaterMan

What Burnham boiler? What control is the ignition wire connected to? I'm leaning to the control causing the chatter in the valve. If that control is a multi function control that everything connects to with molex multi pin plugs, your repair price may be a bit high. If it is just a ignition only control like the S8600, and the circulator wires are connected elsewhere, then the replacement ignition control will be more affordable.

Wish you well

Mr. Ed

mattmia2

You need to check gas pressures as well. You could have a problem with the house regulator for the lp, the regulator in the gas valve, or some other gas supply issue. It could be electrical or the valve, it sounds like you are not getting enough gas because of some failure since there is both a noise and ignition issues.