Weil McLain HE6

Boilerpro_3

and no solution was found. Flame just does not carry over between burners. All three have since been replaced.

The factory gas valves on mine were step opening. One had a fast opening replacement valve installed and that one light off reliably.

Boilerpro

John Starcher_4

Weil McLain HE6

I am servicing a HE6 Series 2 Boiler set up for LP.I have a problem with all the burner tubes lighting.This is what I have done:
Cleaned the tubes,orfices,and manifold.
Burner tubes were replaced 1 year ago with steel tubes.
I have 10.5"WC on the outlet pressure.
Pilot is between burners 6&7.These 2 burners will light.Every 4-5 times when there is a call for heat,6&7 will light,then in approx. 20 seconds,the other tubes will light.There is no hard lighting or mini explosions when the other tubes light.
Combustion analysis is as reads:
Efficiency 81.0%
Excess Air 169.0%
Stack Temp. 278 Deg. F.
O2 13.6%
CO2 4.8%
CO 13 ppm
CO Air Free 37 ppm
Draft -.04 WC
These readings were with all burners lit.
I know the O2 is high,but I have no way of adjusting as there are no shutters.
Any help would be grateful.
Thanks,
Ray

rudy_2

Where are you taking the test?

You are right, the O2 reading is way high (should be more in the 7% to 9% range). Stack temp also looks low.

Are you taking the test after the diverter (if there is one) or before the diverter?

rudy_2

Where are you taking the test?

You are right, the O2 reading is way high (should probably be more in the 7% to 9% range). Stack temp also looks low.

Are you taking the test after the diverter (if there is one) or before the diverter?

Typically air shutters don't have that much control over combustion air, my guess is that the equipment is underfired (assuming the testing was done before the diverter.

Personally, I'm not familiar with that unit but I think I would double check the manufacturer's specs on gas pressure and make sure it has the right orifaces.

Ken_8

Sounds like the gas valve is sticking and slow opening. Try a wooden "whack" and see if the burners all fire up in concert with whacking the valve.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Contractor"

Ray_7

I took the reading about 1' out of the boiler in the flue.This is an inducer style boiler with no diverter.Mike(Tech.Service)at Weil McLain has been VERY helpful trying to help resolve this with me. I couldn't get the boiler to full fire to do an overfire test. Thanks for the responses.
Ray

rudy_2

Well....

You are taking the sample from the proper location. With that high of an O2 reading and low of a stack temp, I still would suspect it's underfired. What did Mike say the gas pressure should be?

Any chance it was designed for a higher altitude and had the orifaces derated or is it a two stage unit not firing at full fire - although if you have 10 1/2" at the manifold outlet it should be at it's full rated capacity.

ken from nw ohio

Weil boiler

Had an HE-4 do that this fall. We raised the boiler 1/4" to make the burners go downhill a bit. Cleared that one right up.