Flameout on startup

Randy54

ON startup the gas valve opens and as the pilot lights the gas i get some rolling flame out each end of the bottom of the stove. Not much but the area in the front houses the gas valve and wiring  and should not be subject to any flame at all. The draft is good and the chimney is clean and while burning everything is fine it just on startup. its hard to see between the boiler sections from the top cuz they are offset for max heat xfer.

But it is venting fine while running. The gas valve is a new replacement fir the original OEM  one. THe pilot light assy is new. pilot seems strong but tried to turn it down and the adj screw seems to have no or little effect,but i dont think thats causing the flame rollout problem though.

THeres about 1/2 inch high by 6in wide space to view  the flame,thats where the rollout occurs thinking there should be some kind of metal piece there that can be removed to service but reinstalled for running. but i dont want to add any thing that wasnt there originally.

Its an older pilotlighted gas boiler. i just installed it a few weeks ago and the problem get worse if i put the front cover on on im leaving it off for now.  Small about 70000 BTU

 

Tim McElwain

Let me get this

straight this is a new installation is that correct? If so why was the gas valve changed? The gas valve and pilot both being changed could be why the flame is rolling out. Find out what the original valve and pilot requirements were for the unit. It also sounds like the inside door to the burner area is missing if I read your posting correctly.



Is this a used boiler is my next question?

Randy54

Flame rollout

Im guessing this boiler is at least 15+ years old ,dont think they make them with pilot lights anymore.The gas valve was changed because the old one was sticking,new valve is a direct replacement for the original which they dont make anymore.Pilot light assy was changed because old one was partially blocked. Also the flame is mostly yellow some blue,wont adjust well with the air intake. Going to try cleaning the burners possibly rust accumulation inside. Flame roll out is minor and only on start up but i feel there should not be any rollout at all. I dont see a place where a  flame viewing cover would attach so im not sure if it ever had one or not. Ill get some make and model info to see if i can get a diagram or manual online.

Ironman

Natural or L.P.?

Which fuel are you using? If you're on L.P., then the new valve would have to have been converted to L.P.. The conversion kit should have come with the valve. In either case, the manifold pressure would require setting. What's your manifold pressure?



You'll need to get this corrected immediately; that yellow flame is indicative of a serious problem.



You have a dangerous carbon monoxide concentration when there's a yellow flame.

Randy54

NG or LP

The boiler is NG not LP and all the new parts are for NG not LP.  The yellow flame is a mixture of blue and yellow,and being the draft is good im not getting and flue gas spillage while its running just the small flame rollout on startup,i think it is rust in the burners ,ill try cleaning it out today.I didnt even notice it at first ,but only after i installed the front cover that covers the gas valve did it make it worse. Im running it without the front cover till i get it corrected    THeres a lot of rust in and around the burners and boiler interior cuz it sat unused for years. I was surprised it didnt leak,but not a drop of water leakage, Im going to vacuum the cast iron burners out today and ill update after that.

Ironman

Dirty Burners

Vacuuming may help, but it won't get the dirt out thoroughly. The best way is to remove the burners and wash them thoroughly in hot water. Use compressed air also to purge and dry them before you re-install them.



You still need to set the manifold pressure. This is critical and may be a large part of your problem.



Make sure the burners are properly seated on the gas orifices before you turn the gas on.

Tim McElwain

Randy do you know how to

clock a gas burner using the test dials on the meter? You need to do that and it should match the input to the boiler. You also need to check gas pressure on both the inlet and outlet side of the gas valve.The required pressure will be on the rating plate for the boiler.



I suspect you are not really seeing yellow in the flame but orange which is the result of you stirring up dust and rust as you service the equipment.



Do you have an electronic combustion analyzer? If you do then a combustion analysis should be done on the boiler.



We are here to help you with any questions you may have. Remember Carbon Monoxide is colorless, odorless and undetectable with any human senses. You must test to find out. Also make sure you have a good draft on both sides of the draft hood or barometric whichever is there.

Randy54

Update on flameout

TIm

You hit the nail on the head ,the flame is blue & orange from the rust burning

I cleaned the burners today, not easy getting them out ,must have got 2 lbs of sand like rust out. The gas valve is a Honeywell VS820A1047 powerpile universal 750Mv replacement. It handles 50-250 Th BTU boilers. Valve pressure is adjustable from 3-5PSI. I turned the manifold pressure down as the boiler is only 70000 BTU so pressure must be on the low side. Also it cycles on and off a lot since it is only servicing 40 Ft of baseboard at 180 Deg F. Turning the pressure down seems to cut down on the cycling. I have good draft and a draft hood 12" above the stove     This boiler is only about the size of a medium suitcase. Called an ackamatic made in Mcdonald PA,probably out of business. Cant get anything by googling the make or model  THe boiler plate does not list the manifold pressure. Although the boiler is running better now the flame rollout has not changed.   Im almost convinced the flame roll out is caused by a missing inspection plate. Its allowing some gas to spill out the sides before it lights off. I have a similar boiler in another house and there is indeed a plate that is removed for servicing but get replaced for operation just like a gas water heater. There is a 3 inch high by 8 inch wide area in front of the burners and pilot mounting which is where the flame licks out on startup.   Tomorrow i may fashion a sheet metal cover to try.

Ironman

Gas Pressure

"I turned the manifold pressure down as the boiler is only 70000 BTU so pressure must be on the low side".



Randy,



The btu input is not determined by manifold pressure ( though lowering it will decrease btu's). The btu input is determined by the size and number of burners. In other words, you don't give it less pressure for a smaller appliance and more for a larger one.



The manifold pressure must be set correctly in order to achieve proper combustion and avoid under or over-firing. Under firing will cause condensation to form which will rot the flue piping and eventually the boiler. It will also attack the mortar joints in the masonry chimney which can lead to the interior collapsing and then causing flue gases to spill into your home. That means CARBON MONOXIDE!



Please get the pressure set correctly with a manometer. We don't want you to be a statistic in the CO section.

Randy54

Ironman

Manifold pressure is not on the MFG plate.  I know its not under firing as the on off cycle is still pretty short. Just a few minutes   Ill keep trying to find the info but  i think this boiler may be too old or Co. out of business. AS i said the whole furnace is no bigger than a medium sized suitcase. I may have to use the BTU rating to set it up correctly.    

Tim McElwain

Randy, it appears

that you are not listening to what we are asking you to do here.



1.  Did you take a gas pressure?



2. Do you know how to clock a burner?



3. Do you know what an orifice is?



4. Do you have a combustion tester?



If you can't answer yes to all of those questions you need help from a pro who should be able to answer those questions.

Randy54

Reply

Tim

I do not have the instruments for some of what your asking,however

Im doing things in the order of importance.

Keep in mind this boiler is in operation right now and i have no substitute heat as outside temps are hovering around freezing.

Clocking the burner is one thing i can do without instruments,ill do that soon.

The orifice for the pilot light is the correct one for the NG the part came with an extra one for LP   I believe the NG is .018 and the LP is .010  But the part came already set up for NG.



HIring a "pro" did not work out well in the past . Iv had poorly trained service people  damage furnaces  just doing regular maintenance. I live in a rural area,and would rather buy the instruments myself if i need them as i do rehabs which sometimes require furnace installs for the last 25 years.Iv installed  oil,gas,coal and wood stoves over the years.

In this case the gas boiler is an old one that needs more diagnostics than im used to.doing.   Getting a combustion tester would be a good idea as i could use it for a variety of different furnaces.

Thanks for your help so far ,with it i have this boiler working much better already after i make an inspection cover for it ill post the results.

DO you have any suggestions as to what to do in this case where there is no manifold pressure req. on the ID plate of the boiler?

Before i buy an instrument to check it i would need to know what it should be.

Thanks  

Tim McElwain

Randy here is the

problem it sounds like you need some training. What is your location? Are you a licensed contractor?



To try to help you with this job here is a good starting point:



1. Get a manometer (u-gauge) the vale you have 1/8 plug on the outlet side you need to check the pressure it probably should be at 3.5" W.C. (water column).



2. Clock the burner using the gas meter it should match what the boiler lists as input.



3. Repair the fire door as you said you were going to do.



4. Do a pilot safety turn down test.



5. Make sure that the gas valve that was removed was not a step opening valve.



6. Get hold of someone who has a combustion tester, try an oil man they are usually pretty good with testing.