Lochinvar Knight Burned Up

Billlimoges · March 21

Hi everyone,

Any ideas how this could happen?

The front cover of the boiler melted through, and caused a bit of havoc in the building.

The company that does maintenence says it's been serviced within 14 months.

I'm a heating contractor, but this isn't my unit - I went to look at it out of curiosity, because it's our community center's boiler, and I'm a city councilor. Both the heating company's tech, and myself were scratching our heads about this.

If anyone has insight on the matter, it would be greatly appreciated, as there's 2 other boilers on either side, and I'm a little concerned about having something similar happen.

1st picture is a little out of focus, but I've circled the flame rod - it fell out.

2nd photo is where the plate melted through.

Thanks in advance!

GGross · March 21

The flame rod falling out seems a pretty big clue. I don't mean to make any accusation but I have seen on very rare occasion a service tech forget to tighten the screws on the flame sensor or igniter… Now I've never seen this result from it so I'm a bit hesitant to make that my final answer. Can you find the screws for the flame sensor? Wondering if they are stripped, maybe something happened with the combustion and it blew out the rod. One would think the unit would pretty quickly shut down once the flame rod was out of the unit so I am kind of leaning toward something more combustion related rather than negligence

Alan (California Radiant) Forbes · March 21

The company that does maintenence says it's been serviced within 14 months.

Check with them to see what kind of maintenance they did. Yearly maintenance should include removing the burner and inspecting the heat exchanger. A build up of debris could have cause this; perhaps a deteriorated refractory, clogged fire tubes ……..

Open the boiler up and take some pictures.

Steamhead · March 21

Did it run out of water and dry-fire?

pedmec · March 21

My guess is they damaged, misaligned, or just for forgot to put the gasket between the mixed air/gas tube and the burner door. I don't think a gasket leak past the flame rod can do that kind of damage unless the screws ain't tightened and fall out. the flame rod and igniters are so easy to replace and tighten up. Damaging or forgetting the gasket is what I've seen techs do. we service a lot of Lochinvar's. lots of PM contracts

mattmia2 · March 21

However this happened:

Lochinvar Boiler Leaking Gas

Alan (California Radiant) Forbes

Mar 3, 2025

I received an impassioned text today from a SF customer where we installed a KHB boiler 6 years ago. He said that there was a strong gas smell coming from the boiler whenever it goes into high fire. They’ve shut the boiler down until I get there in the morning.
It’s a radiator system with the boiler vented through the roof; makeup air a separate pipe from a sidewall to the outside. There’s also an indirect water heater.
Perhaps one of the PP vent connections separated even though we used lock rings. Any thoughts before I go out there?

Derheatmeister · March 21

GGross

Mar 21, 2025

The flame rod falling out seems a pretty big clue. I don't mean to make any accusation but I have seen on very rare occasion a service tech forget to tighten the screws on the flame sensor or igniter… Now I've never seen this result from it so I'm a bit hesitant to make that my final answer. Can you find the screws for the flame sensor? Wondering if they are stripped, maybe something happened with the combustion and it blew out the rod. One would think the unit would pretty quickly shut down once the flame rod was out of the unit so I am kind of leaning toward something more combustion related rather than negligence

A Fact on the LOCHINVAR Knight boiler : When the Flame rods are disconnected the boiler will continue to operate Since it also uses the Spark ignition rods as a flame rectification ! Try it..😐️

2.Agree with the gasket for the sensor and Ignitor…We have seen that when the Gaskets for the rods deteriorate it can melt the wiring.

Based on the pictures this boiler is a total loss..It Needs to be Red tagged and replaced..

It may be time to talk to your Local rep,Lochinvar and your insurance Company.😕

Derheatmeister · March 21

I had a tech that for whatever reason stated not securing the burner plates and the gas lines !! One home got flooded with Natural gas while other filled up with Carbon Monoxide…

We got very lucky and noone got hurt!

THIS VERY DANGEROUS AND FRUSTRATING !!!!!!.

In order to make sure that these situations did not continue i send him to a training with NCI to understand the serverity and consequences that this can have.

I also inplementend that after ALL screws/Bolts to the Burner plates/Gasvalves/Blowers were secured a dab of nail polish was put on the screws and a picture of it with the customers initials was taken and send to the Office as proof.

It is kind of like the NYC Subway conducter requirements to point at the sign on each station…Painfull but it worked.

https://www.dailymotion.com/video/x16n3pc

Steamhead · March 22

Derheatmeister

Mar 21, 2025

I had a tech that for whatever reason stated not securing the burner plates and the gas lines !! One home got flooded with Natural gas while other filled up with Carbon Monoxide…
We got very lucky and noone got hurt!
THIS VERY DANGEROUS AND FRUSTRATING !!!!!!.
In order to make sure that these situations did not continue i send him to a training with NCI to understand the serverity and consequences that this can have.
I also inplementend that after ALL screws/Bolts to the Burner plates/Gasvalves/Blowers were secured a dab of nail polish was put on the screws and a picture of it with the customers initials was taken and send to the Office as proof.
It is kind of like the NYC Subway conducter requirements to point at the sign on each station…Painfull but it worked.
https://www.dailymotion.com/video/x16n3pc

I would have just fired him. Too much liability.

Derheatmeister · March 22

Steamhead

Mar 22, 2025

https://forum.heatinghelp.com/discussion/comment/1849270#Comment_1849270
I would have just fired him. Too much liability.

I am glad that i Gave him a second chance by Sending him to a NCI class..I think that this class opened his eyes and help him. He now owns his own Company up here in the high country and we still talk.

tim smith · March 24

I would absolutely want to see the inside of heat exchanger and the blast tube external mounting gasket and the burner head to mounting plate. Looks like to me the blast tube flange or burner head flange on inside could have been blow torching where it mounts to plate and was blowing downward to the location of burn through. Just a big guess. Also easily could have been caused by restricted water tube heat exchanger. Taking heat exchanger/burner plate will tell you a lot.

hot_rod · March 24

tim smith

Mar 24, 2025

I would absolutely want to see the inside of heat exchanger and the blast tube external mounting gasket and the burner head to mounting plate. Looks like to me the blast tube flange or burner head flange on inside could have been blow torching where it mounts to plate and was blowing downward to the location of burn through. Just a big guess. Also easily could have been caused by restricted water tube heat exchanger. Taking heat exchanger/burner plate will tell you a lot.

I too think, something was mis-assembled after the last clean and check.

I'd get the local Lochinvar rep involved in the forensic work of taking it apart.

Lochinvar Knight Burned Up

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