enerjet boiler issue

nytech28

i checked this boiler , that was worked on before me & left cold dead , repalced thermocouple & cleaned out the burner tubes , got the boiler running , found expansion tank no air causing relief vavle to open , gas vavle  fires up burners normally @ first , but when it fires up 2nd time ,flame rolls out the burners & trips rollout switch/ & again gas vavle gets 24volts sends gas to burners with pilot light off dangerous situation, also found other issues but these issues are enough to post , any one in the field had similar issues with gas valve acting ubnormal , please share . 

109A_5

Hello @nytech28,

nytech28 said:

but when it fires up 2nd time ,flame rolls out the burners & trips rollout switch/ & again gas vavle gets 24volts sends gas to burners with pilot light off dangerous situation

Few things;
The flame rollout issue should be repaired.

If the pilot is blown out by the rollout event it may take a moment for the thermocouple to cool down and then cut off the gas.

But why is the gas valve still getting 24 VAC if the flame rollout switch is tripped ???
Sounds like a wiring error !!!

With any tripped safety switch the gas valve should not get 24 VAC !!!

Big Ed_4

That boiler is sooted up , it needs to be opened up , and brushed out . Every bit of carbon out with a gas unit..

Closet job ... make sure you have proper fresh air for combustion . Normally draft and air is the issue ...

nytech28

looks like  wired correctly , like you mentioned thermocouple was hot probably toke some time to cool down to stop gas flow , I checked gas pressure to make sure it was upto specs , only thing that can cause rollout situation would be draft issue or dirty heat exchanger/ tubes , if you take a look at the burners tubes ,one of the tubes are closer to the manifold orifice circled in red then the other tubes , is that suppose to be next to the burner tube with the  pilot assembly ? trying to find info on the boiler but no luck. I got few extra parts like gas vavle incase I need it .

nytech28

Big Ed_4 said:

That boiler is sooted up , it needs to be opened up , and brushed out . Every bit of carbon out with a gas unit.. Closet job ... make sure you have proper fresh air for combustion . Normally draft and air is the issue ...

i.ll have to check fresh air duct make sure no blockage  , but as I mentioned when the boiler starts up fresh it works fine .

109A_5

Hello @nytech28,

nytech28 said:

looks like  wired correctly ,

How could it be wired correctly ? If the gas valve is getting 24 VAC with the rollout switch tripped !!!

Those burner tubes all look like they are placed slightly different. Where should they be ?

nytech28

109A_5 said:

Hello @nytech28,

looks like  wired correctly ,

How could it be wired correctly ? If the gas valve is getting 24 VAC with the rollout switch tripped !!! Those burner tubes all look like they are placed slightly different. Where should they be ?
when I got the initial service call I found the burner tube on the floor so I placed it back where it was missing , not sure who ever worked on it before moved them around, & no info online for this boiler so far. As for the gas valve it does drop 24volts to GV when rollout trips but it resets again providing 24volts was kinda tricky at beginning. but I will be going back to fix this mess & make sure safetys are in place & working, any recommendations as for flame roll out issue ?? would be apreciated cause that's the main issue , Aside from a bad ex-tank, low water cut off. & possibly bad  pressure relieve valve opening up to many times before I serviced it.

EBEBRATT-Ed

Could be the angle of the picture and probably is but 1 of the burner tubes looks off center to the orifice.

Steamhead

Is this a cast-iron or a copper fin-tube boiler?

nytech28

cast iron