TL;DR: is it possible that my E04 code is being caused by the gas manifold simply falling out of place causing the burners not to ignite? So far, propping up the manifold (where it normally falls open because its screw hole is rusted) seems to be all that's needed to fix* my annoying E04 code.
My heater started making a TON of noise as it ran so I finally broke down and decided to open it up and try to salvage it. Predictably everything rustable and corrode-able had done so, especially the fan that was causing the vibration and the noise. (Unpredictably, it did not leak, not at all!) I replaced the fan and all of the baffles covering the heat exchanger, scraped out as much rust as possible, and re-sealed everything I could considering the substantial amount of rust still remaining (this was more or less a salvage job, after all). I fired it up and ran beautifully - honestly better than I was expecting. But for some reason, and this had never happened before, I started getting E04 error codes. I checked the air flow sensor, capacitor, vacuum tube, everything appeared fine enough. Still, E04 codes. Until yesterday. Yesterday I opened up the service panels to visually inspect and be sure everything was firing up properly. The only adjustment I made was to prop up the gas manifold** so it was sitting against the burner tray like it was supposed to. (The hole it was screwed into was rusted and it had a tendency to fall over due to vibration.) Fired it up and it ran all evening. This morning, E04. Started it up twice, E04. Opened it up. Manifold had fallen over. Propped it back up. No E04.
Obviously the manifold serves a purpose, but I'm surprised (and cautiously delighted) that it's the culprit. Seems like with it down the burners have trouble igniting due to too much air flow and that triggers an E04. Is this issue solved for me? I honestly don't know that much about these heaters to say, except that I'm getting results at this time.
* Obviously not the only thing that causes E04 codes. Just wondering if that's the actual culprit in my situation.
**Part #34 on the 2nd page of this parts list Pentair NT 400 Parts List and Diagram : eReplacementParts.com).
My heater started making a TON of noise as it ran so I finally broke down and decided to open it up and try to salvage it. Predictably everything rustable and corrode-able had done so, especially the fan that was causing the vibration and the noise. (Unpredictably, it did not leak, not at all!) I replaced the fan and all of the baffles covering the heat exchanger, scraped out as much rust as possible, and re-sealed everything I could considering the substantial amount of rust still remaining (this was more or less a salvage job, after all). I fired it up and ran beautifully - honestly better than I was expecting. But for some reason, and this had never happened before, I started getting E04 error codes. I checked the air flow sensor, capacitor, vacuum tube, everything appeared fine enough. Still, E04 codes. Until yesterday. Yesterday I opened up the service panels to visually inspect and be sure everything was firing up properly. The only adjustment I made was to prop up the gas manifold** so it was sitting against the burner tray like it was supposed to. (The hole it was screwed into was rusted and it had a tendency to fall over due to vibration.) Fired it up and it ran all evening. This morning, E04. Started it up twice, E04. Opened it up. Manifold had fallen over. Propped it back up. No E04.
Obviously the manifold serves a purpose, but I'm surprised (and cautiously delighted) that it's the culprit. Seems like with it down the burners have trouble igniting due to too much air flow and that triggers an E04. Is this issue solved for me? I honestly don't know that much about these heaters to say, except that I'm getting results at this time.
* Obviously not the only thing that causes E04 codes. Just wondering if that's the actual culprit in my situation.
**Part #34 on the 2nd page of this parts list Pentair NT 400 Parts List and Diagram : eReplacementParts.com).
