I concur with [pdy18]. I only needed to do a CLR flsuh the first time, since I wasn't on top of maintenance for the first several years. That cleared out the dark soot. Now that I am more consistent, I just flush annually with vinegar as [pdy18] indicates. The kitchen sink water smells like ketchup for a minute or so then clears quickly...I concur with [pdy18]. I only needed to do a CLR flsuh the first time, since I wasn't on top of maintenance for the first several years. That cleared out the dark soot. Now that I am more consistent, I just flush annually with vinegar as [pdy18] indicates. The kitchen sink water smells like ketchup for a minute or so then clears quickly...
I followed 'pdy18's suggested solution. It definitely cleaned out a lot of sooty-like (black) condensate from the coils. I used CLR in recommended proportions, flushed the system for about 30 minutes with 1/4HP pump.
No luck though, C4 or C7 then coded 35 still occuring :-( I found what the code actually means here: http://www.palomastore.com/paloma_error_codes.html. It appears one or more of the thermistor sensors has gone bad. I never made any PCB connection changes to the thermistors or even opened the case (the recommended fix in the error code links was to verify thermistor connections are correct, doesn't really make sense if it was working before the code). So I called Rheem and they said the PCB has gone bad and fedex'ing me a new one with a progamming chip. Looks like I will be following p55giordano's excellent post here next: http://www.fixya.com/support/t1921087-paloma_heater_shuts_off to change out the PCB tomorrow. One more day of cold showers builds character. Don't tell my wife, I am sneaking hot showers at work...
Side note: No need to purchase a $165-$218 flush kit from Rheem. I bought a new 5 gallon bucket, CLR, small 1/4HP electric fountain pump (with "5/8 garden hose connectors already on it), 15' garden hose and 2 extra female hose adapters (I cut the garden hose into 3 - 5' sections) for $119. Now I can flush the tankless water heater annually as recommended with a small CLR purchase for the hardwater here in NJ, yeah!
Answers & Comments
Flush it with vinegar
I concur with [pdy18]. I only needed to do a CLR flsuh the first time, since I wasn't on top of maintenance for the first several years. That cleared out the dark soot. Now that I am more consistent, I just flush annually with vinegar as [pdy18] indicates. The kitchen sink water smells like ketchup for a minute or so then clears quickly...
I followed 'pdy18's suggested solution. It definitely cleaned out a lot of sooty-like (black) condensate from the coils. I used CLR in recommended proportions, flushed the system for about 30 minutes with 1/4HP pump.
No luck though, C4 or C7 then coded 35 still occuring :-( I found what the code actually means here: http://www.palomastore.com/paloma_error_codes.html. It appears one or more of the thermistor sensors has gone bad. I never made any PCB connection changes to the thermistors or even opened the case (the recommended fix in the error code links was to verify thermistor connections are correct, doesn't really make sense if it was working before the code). So I called Rheem and they said the PCB has gone bad and fedex'ing me a new one with a progamming chip. Looks like I will be following p55giordano's excellent post here next: http://www.fixya.com/support/t1921087-paloma_heater_shuts_off to change out the PCB tomorrow. One more day of cold showers builds character. Don't tell my wife, I am sneaking hot showers at work...
Side note: No need to purchase a $165-$218 flush kit from Rheem. I bought a new 5 gallon bucket, CLR, small 1/4HP electric fountain pump (with "5/8 garden hose connectors already on it), 15' garden hose and 2 extra female hose adapters (I cut the garden hose into 3 - 5' sections) for $119. Now I can flush the tankless water heater annually as recommended with a small CLR purchase for the hardwater here in NJ, yeah!