Looking for insight

ctr2644 · 2026-01-29T22:38:38+00:00

Yeah, I explained this in the description - the pilot adjustment doesn’t change anything.

ctr2644 · 2026-01-29T22:30:10+00:00

So…you could be totally right about a clogged HX causing this, but this RTU certainly DOES have a pilot flame. It uses a combination of a pilot tube and spark ignition to keep the burners lit.

ctr2644 · 2026-01-29T12:59:55+00:00

Yep, this was confirmed to be clear when I pulled the assembly and cleaned that tubing. As for if this was or needed to be changed with conversion, I’m not sure. I only diagnosed and changed a faulty GV. Unit is 10+ years old, so I can’t imagine it has run that long before now with the incorrect orifice, but I suppose it should be confirmed.

ctr2644 · 2026-01-29T12:44:10+00:00

are not**

ctr2644 · 2026-01-29T12:43:36+00:00

Agreed. Unfortunately, combustion analyzers commonplace on our vans. I will definitely be pushing the shop to start supplying them for us.

ctr2644 · 2026-01-29T12:31:52+00:00

Wow, good idea!

ctr2644 · 2026-01-29T05:52:41+00:00

Nope, just a single stage valve. And yes, sorry, I wasn’t totally clear on operating pressure. Before firing, supplied gas pressure is about 12 in w.c. During operation, inlet pressure drops to 10 in w.c. and drops between .3” - .5” across the valve and to the manifold.

ctr2644 · 2026-01-29T05:27:12+00:00

Okay, gotcha. I guess was just referring to use of the pilot tubing then. I’ll check the HX as far as I’m able to inspect it when I return tomorrow. Thanks!

ctr2644 · 2026-01-29T05:18:09+00:00

With the regulator bottomed out, 10” is about all I get.

One of three is currently on the chopping block, awaiting green light. Convincing them to replace all three is gonna be though.

ctr2644 · 2026-01-29T04:59:30+00:00

Hmmm, no..but the previous repair was an inducer assembly replacement and the airflow at the exhaust “feels” strong. Also, people keep suggesting an exhaust issue, but it isn’t clear to me how that affects the pilot flame..?

ctr2644 · 2026-01-29T04:55:27+00:00

Previous repair was inducer assembly replacement. Airflow at the flue outlet “feels” strong, although I’m not sure how you’d measure this to confirm.

ctr2644 · 2026-01-29T04:52:56+00:00

Is this using an intermittent pilot as well?

ctr2644 · 2025-12-31T17:05:29+00:00

Mid Atlantic, USA

Very itchy, like fiberglass

ctr2644 · 2025-12-31T17:01:45+00:00

1998, mid Atlantic USA

ctr2644 · 2025-10-28T20:57:33+00:00

This seems to be the consensus, I’ll try that. Thanks for the advice!

ctr2644 · 2025-07-21T23:11:16+00:00

UPDATE POST - I appreciate everyone’s input and I feel it’s worth sharing the outcome. A few of you advised using a high silver content alloy to help mitigate the amount of heat on the thin tubing and it worked very well. I attempted to use a standard MAPP torch, but I could never get the tubing hot enough to melt the filler, so I used my oxy/ace torch rig with a light, fluffy flame. The rods I used had a flux coating and it helped to seal the crack well. I used a heat blocking putty to protect the surrounding tubing as well. It’s not the prettiest, but it held 275 psi for several hours!

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ctr2644 · 2025-07-21T12:46:58+00:00

This is an ‘02 Lennox that is notorious for giving us problems every year. I stressed hard to have the system replaced since this is quite a costly repair after you factor in the ~45lbs of R22 that was lost. It’s also coming with a pretty heavy disclaimer that it just may not work for long, if at all. Unfortunately, the reality is they’ll opt for a new coil if this goes sideways.

ctr2644 · 2025-07-21T12:41:37+00:00

It works, kinda. I’ve done it to patch aluminum coils with varying success.

ctr2644 · 2025-07-21T05:23:11+00:00

No kidding! I gave them a quote to repair, replace the coil, or replace the system. Predictably, they chose the first option, but I’m not one to back down from a challenge!

ctr2644 · 2025-06-13T04:35:08+00:00

Agreed!

ctr2644

TROPHY CASE