Our First WM LGB

The Steam Whisperer

Old Leaking oversized LGB was replaced with this. Since there were no longer any more efficient models, you have to go with what you can get. We were also fortunate that there the chimney connection was high enough so we could use the LGB.....we just barely met the installation requirement of the 3 feet of vent pipe height above the draft hood before going over to the chimney. This requirement is universally ignored around here. We got one of the last 3 boilers still available here in Chicago

However, as usual, we had to deal with defective components. This time the high fire rate was set so high that it would pull the pilot flame off the sensor. Several hours of checking wiring, etc. and the techs noticed the sensor not staying red shortly after the boiler would go to high fire. Ran low fire not problem.
We my need to increase our labor surcharge over the current 5% surcharge we have started adding a year ago to cover the constant issues with defective components on new boilers.

delcrossv

Nice! That's a Loooooong header? Wonder what required that.

Steamhead

Well, now we have a chance to see how an LGB will perform and how long it will last when properly installed. Not one of the LGBs I've seen were installed as well as yours is.

How big is that vent pipe? Do they make a stack damper that big?

The Steam Whisperer

delcrossv said:

Nice! That's a Loooooong header? Wonder what required that.

That was what was there. The old LGB had 2- 4nch risers running to the middle 6 inch supply. You can see the one capped off to the right behind the return drops

The Steam Whisperer

Steamhead said:

Well, now we have a chance to see how an LGB will perform and how long it will last when properly installed. Not one of the LGBs I've seen were installed as well as yours is.

How big is that vent pipe? Do they make a stack damper that big?

It's an LGB-8, replaced a LGB-13. Vent is 14 inch, 3 foot minimum height off the draft hood. The venting requirements on Pg 7 of the IOM only spec the height, so you can probably go down to a 12 inch with the high draft of a 35 foot chimney. That's something I'll look into for the owner. I think you can get custom made dampers as big as you want, but 12 inch is standard fare.
On LGB's without dual welded riser headers stressing the block, the typical life we see is about 24 years ( all the gaskets fail). The typical welded header setup is about 14 years. With welded header, but with treaded connections per the WM recommendations, they seem to get closer to the 20 year plus mark. We did have one over 30 years old, but was very well cared for ( I don't know if it had been regasketed at some point).

We added a 3rd pressuretrol to take advantage of teh built in high/low. I never did a radiation check, but the old boiler was running with just one base (780,000 input) and heated the building through some 0F weather.

veteransteamhvac

What pressures are you using for the low-high-low firing changes? Any pressure change input from the condensate tank to modify the low-high-low?

The Steam Whisperer

We will be seeing hot the Penn Pressure controls work at low pressures. I am shooting for low fire at around 1 psi.

ChrisJ

What kind of tiny vent pipe is that? I've seen bigger on a Civic......

What is that, 10"? 12"?