t VHE ^ cold start flame back out the tubes

ljc2850

My VHE 6 installed 1990 if the tem is 110 on the gauge and the boiler starts I get flame out of some tubes I shut it down then back or and it runs fine as long as the temp can stay above 120 degrees any suggestions would help Thank You!

EdTheHeaterMan

Propane or natural gas?

mattmia2

i don't know what a vhe 6 is but look for the boiler being scooted and for burners that are damaged or clogged. Some burners have designs that rust out and collapse or are damaged of they aren't set up right. make sure you have enough combustion air, that you don't have a sealed off room around the boiler or an attic fan or something. if it is soot or you don't find either of those things, you need someone that understands combustion.

EdTheHeaterMan

I believe the VHE 6 is a 6 section Weil McLain boiler that is vented with AL29-4c stainless steel pipe out a side wall or vertical thru the roof. The combustion air comes from inside the boiler room. I believe that the problems that @mattmia2 mentioned are all possibilities. The reason I asked about Propane is that a flame inside the burner tube happens more often on propane burners when the gas pressure is improperly adjusted. 

hot_rod

VHE very high efficiency boiler

HVACNUT

I wouldn't think boiler temperature has anything to do with "Flame out of some tubes". Are you saying not all burner tubes light the first time? Then it needs service. When was the last time it was serviced? Is there a combustion report around?

From the Homeowner Information Manual.

mattmia2

https://forum.heatinghelp.com/discussion/comment/1858001#Comment_1858001

It isn't boiler temperature but flue temp, the vent is drafting better when it isn't cold but there is some root cause that needs to be figured out.

Big Ed_4

I agree , it needs service .. The roll out is a tell tail sign ..Do you notice any soot ? Draft inducer may be weak , when was the last time it was changed ? … Thinking cold boiler.