Smith GB100-W-Anything Constant Pilot Ignition

Firedragon_4

Have you talked to Tom Ferrante at Smith?

scott337

GB100-W-Anything Constant Pilot Ignition

I have seen a few of these where there is an issue with pilot outages on a CONTINUAL basis. My guys have changed thermocouples thinking this was it (because it was late night as well) but the outages continue to occur. The inlet and outlet pressures on both sides of the manifold are within spec of the manufacturer, there is power and current to the gas valve and the damper is operating properly and is within manufacturer spec. The outages are sporadic but a pain (for obvious reasons). Oh yeah, the boiler is also grounded properly and the sympton seems to occur on 3 to 4 year old boilers. Any help?

scott337

Duh- Its a Smith Boiler by the way,

Unknown

Many causes of Pilot outage

Some questions to consider-

1. Do you have sufficient air for combustion and if so what is the source of air for combustion, openings, mechanical etc.???

2. Is it possible that with fans, fireplaces, dryers, and any other device which can change the pressure in the combustion area is causing this? You are a detective and maybe they only run the fireplace every so often, did the pilot outage occur after the fireplace was run?

3. Have you taken millivolt readings and at the same time done a combustion analysis?

4. You might also try a nickle plated high temperature thermocouple from Johnson Controls it is a K16RA model.

5. Is there any other equipment in the vent with this boiler?

6. What kind of vent is it a chimney or a double wall vent?

7. Take one of these apart and see if there has been a change in the flue passages inside the boiler.

8. The fact that you have had a few of these I assume on the same boiler as George says get the factory involved.

9. Look for cracks or damage to the burners (if they are pressed metal), you really have to take them out and go over them with a good bright light to see small cracks. These open up when hot and cause changes in the air flow across the burners pulling the flame out.

10. Adjust the pilot flame to give the tip a dul red glow. If it is "cherry red" you a welding the tip so soften the flame up and make sure the flame is hitting the upper 1/2 to 3/8 of the thermocouple.

John Lasky

pilot light on Smith GB series

Hello meat ball.

I have a 5 year old GB200 that had the same problem.

and it was a pain.

I think the problem lies in the flame burning out the thermocouple even thoug I could re light id have another outage soon after (day or so).

I noticed on My boiler the pilot assembly holder puts the flame too far down on the thermocouple thus burning it out.

the owner of a burner supply place that I get parts from said it was a common problem and often proper instructions are not given nor are the holders perfect.

Hb smith might have had the holder off a bit.

I since modified my pilot so that the flame touches just the tip of the thermocouple rather than covering 3/4 -1 "

that and a new thermocouple every year problem solved .

I should install a intermittent some day.

"John"

Wild Bill

outages

Meatball,

I used to work at Smith, they had numerous pilot issues 4-5 years ago using brand X t'couples....it seems the boiler base-area retains alot of heat...try the Johnson K16RA nickel plated t'couple, the problem should go away.

Thanks,
Bill Hobbie

Mark Walnicki_2

Agreed!

You *must* use the "heavy duty"' thermocouple in these. Been there, done that, one of the worst thermocouples to replace, and it really makes you crazy when you have to replace the cheapie, brand-x ones year after year after year.

The nickel-plated ones really do the trick, and should give good service for a number of years.

Unknown

It has been my experience

that a lot of atmospheric boilers have issues with very high temperaturesa being created in the vicinity of the pilot on both thermocouple systems and spark ignited systems. It is also a problem and one of the many reasons silicone carbide hot surface igniters fail so often. This is also the cause of pilot outage which may not be a thermocouple failure.

The need to hold more heat in the boiler to reach mid efficiency boilers standards is part of the reason for this.

I have also found that if sufficient air for combustion is provided and the boilers are set up properly with a combustion analyzer these problems tend to disappear. You can either start setting equipment up correctly or change a lot of thermocouples.

I have recently readjusted 5 Utica boilers that had thermocouple issues for two years. They all ran last year without a change of thermocouples for the first time in over three years.

When the flame and air are adjusted and pilot is set correctly the problems go away.

You have to become combustion efficient or change a lot of thermocouples.

I will be the first to admit that I have had one boiler line that no matter what I do it keeps burning out thermocouples. I feel it is poor boiler and burner design.

Jason Grossman_2

Pilot outages

We have had alot of trouble in the past with thermocouples and almost all have been resolved with a proper combustion air supply(direct from outdoors). Smith is the most common one, but any boiler with a built in horizontal draft hood seems to be particularly touchy.