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Hello my name is ***** ***** I look forward to helping you!
What exactly are we working on? Tankless water heater? What brand?
Well I know Rinnai water heaters inside out, but not their heaters. I'm going to request your question get moved from plumbing to hvac. Please wait for that.
Hello, if you can give me the full model number of the wall furnace I can pull the manual on it in most cases and mark up a page or two with trouble shooting instructions.
So far I suspect a restricted vent, (wasps nest etc) or a problem with the pressure switch.
We can go from there.
Hello, locate the pressure switch (PS), then remove the pressure sensing tubes and using a paper clip wire clean out the orifices that tubes connect to. you can locate the pressure switch by following wires attached to terminal 1 and 3 click here
with the power disconnected, suck on the rubber tube lightly and see if you can hear the switch open and close (click sound)
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Thanks, ***** ***** like a bad pressure switch, next use an ohm meter to check between various combinations of the 3 wire connections on the pressure switch as you suck lightly on the rubber tube connection... if the switch is working, you will see the switch open and close on the meter.
Thanks, ***** ***** readings do you get on the same terminals when the pressure switch is just sitting on the bench.
You did well. I am looking for different readings when the pressure switch is sitting on your bench.... if the readings are not different replace the pressure switch.
I am off to bed shortly, if I miss you tonight I will pick up your response in the morning.
You would detach the wiring at the pressure switch and then check the ohms at the pressure switch. Unplugging the connector at the pressure switch would expose the terminals that you check the ohms on.
The ohms test on the bench would be of course with the wires disconnected and that is *perfect. (Ohms is resistance only) No wires need be or should be connected.
Send me a photo taken from about 6 feet away. with the service panel removed so that I can see the set up. then another photo taken from 4 feet away at a different angle.
Use the 'attach files' link to the left of your send button to send the photo's.
Note: the purpose of the ohm tests is to see if the switch position changes when you suck on the pressure sensing tube lightly and when the pressure switch it just sitting there on the bench, no sucking on the tubes for that second test..... you can do the same tests with the pressure switch mounted in the furnace. (just disconnect the wiring to it)
Thanks, ***** ***** switch is bad.. replace it, that should solve the problem.
It is unlikely that there are multiple different failures at the same time... the error codes can also be bogus... lets change the pressure switch and see how it goes.
scroll down their page to their 800# ***** should have the pressure switch... call them on the phone.
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Great, let me know how it works out.
Hello again, had you tried Sears parts.
Rinnai head offices,
give them the part number and the following numbers:
Rinnai Energy Saver RHFE-263FA II-P Serial C8-00-000380
You can also locate the nearest dealer on that page, you need your zip code only
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Hello again, looks like the error code may have been incorrect (that happens a lot). lets do a heat stress test on the printed circuit card that the flame sensor rod plugs into.
Use a hair drier to warm it up to 130F or so, not over 140F. Then while its hot try the furnace again, any change, for better or worse indicates a bad printed circuit board. (cracked micro circuits expand and either get worse or better when warmed up).
We can go from there
Next step if needed will be to fit a U tube manometer to the 1/4" pressure switch tube and measure the vacuum... it is possible that the combustion air blower wheel is clogged with dirt or disintegrated or that the vent is still blocked or you have a split in its 1/4" rubber sensing tube.