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14 month old rheem tankless

24K views 18 replies 11 participants last post by  MACPLUMB777 
#1 ·
Have a rheem indoor tankless heater throwing error code 11. Tech support recommended changing circuit board, did that today and still throws error 11. Checked gas and heater has 9" w.c. Opened gas chamber and no evidence of water. Anyone have any ideas or ran into that problem? I have a sneaking suspicion that it's the silonoid on the gas valve....
 
#2 ·
Circuit board replacement is Rheem's answer for everything. However, usually that resolves the issue (whatever the issue may be) but an 11 code suggests that the unit is never actually firing.

Is that in fact the case, no ignition?

I'm assuming 9" is inlet pressure, what is manifold pressure?

What type of gas system is it on?

Shouldn't have to do this after just 14 months but clean the ignitor with sand cloth. Make sure it is arcing.

Inadequate gas supply should not prevent it from firing, it just won't let you produce full rated capacity, and since it's been working for 14 months I doubt it's a supply sizing issue.

Check the manifold pressure and clean the ignitor and see what happens.

At the end of the day, and although I love their tanks, Rheem tankless is just about the worst crap on the market.
 
#3 ·
smellslike$tome said:
Circuit board replacement is Rheem's answer for everything. However, usually that resolves the issue (whatever the issue may be) but an 11 code suggests that the unit is never actually firing.

Is that in fact the case, no ignition?

I'm assuming 9" is inlet pressure, what is manifold pressure?

What type of gas system is it on?

Shouldn't have to do this after just 14 months but clean the ignitor with sand cloth. Make sure it is arcing.

Inadequate gas supply should not prevent it from firing, it just won't let you produce full rated capacity, and since it's been working for 14 months I doubt it's a supply sizing issue.

Check the manifold pressure and clean the ignitor and see what happens.

At the end of the day, and although I love their tanks, Rheem tankless is just about the worst crap on the market.
Forgot to mention that I did that the first time I went out. Cleaned the flame rods, igniter and changed the igniter coil since he already had a new one from when his other heater went out. It does ignite and flame up initially but codes very shortly after. Did not check manifold pressure, will check when I go back.
 
#5 ·
Plumbergeek said:
I was told Rheems were made by Paloma? My supplier carries them but I will not use em. Rinnai is my Tankless of choice
Rinnai is all we install as well, only call we had on a rinnai turned out to be a clogged shower head not letting enough pressure through to fire the unit. Rheem tankless is complete garbage.

I will also mention that rheem changed their indoor units and they look very similar to rinnai, even take the same consentric vent.
 
#9 ·
About ready to tell these people to throw this heater away and let us install a rinnai. Went back today and got in touch with a level 3 tech support guy who e-mailed me their diagnostic manual. According to their charts the flame rods are bad ( no flame to sense because burner doesn't even fire up all the way ) and the brand new pcb is bad.

Don't know where to go with this one at all, gas valve checks out and igniter is working, a small flame appears while igniting but entire burner doesn't come on causing the flame rods not to sense flame.... I'm stumped. They told me not to check manifold pressure on the new units but to check how much it drops while trying to ignite.
 
#10 ·
Problem solved.

Water was getting in around the roof jack, crusted up the heat exchanger and filled some clear tubing running from the gas valve to the fan with water. Pulled the heat exchanger, cleaned it and drained the water from that tubing and it works like new. I will be giving tech support a call in the morning to find out what that little tube is and maybe give them a heads up for future problems.... Found out the other heater they have had the exact same problem 6 months ago.
 
#13 ·
At the end of the pilot tube is an orifice just where the tube goes into the pilot assembly, This orifice like a top hat on the tube has caused many a code 11 from being plugged. Bring a pin from the wife's sewing kit, a paper clip is to big. Too small a flame to read through the flame rod.
 
#14 ·
PlumberDave said:
At the end of the pilot tube is an orifice just where the tube goes into the pilot assembly, This orifice like a top hat on the tube has caused many a code 11 from being plugged. Bring a pin from the wife's sewing kit, a paper clip is to big. Too small a flame to read through the flame rod.
There is no more pilot tubes on the new rheem heaters. It's all done through milled channels. Don't think you are talking about a tankless either my friend. Rheem doesn't have a pilot on it, much less the same orifice that a tank heater has.

Also, had you read 2 posts up....
 
#15 ·
If this tankless does not have a pilot it must light off on the main flame. This uses a larger gulp of gas at start up and if the system gas reg sticks a little you will have flame fail due to no gas. I had this once and I. Changed out the reg and the problem went away. Also just a side note. Most manufactures want the appliance reg 10 feet or more away due to the fact the regs reaction would be to slow for the volume of gas needed to light off the burner.
 
#16 ·
You shouldn't be using appliance regulators on tankless units, they cannot react fast enough, always use a line regulator at the tankless appliance.

The 10' rule is made up, try to find it in publication anywhere, however if you try to use a appliance regulator on a tankless to step down line pressure to 8", the 10' rule would only help a appliance regulator.

Use a line regulator and distance not only doesn't matter, the tankless will then work properly. Spend double the money for the correct line regulator.
 
#18 ·
It'll also throw a code 11 if it tries to fire when the service valves are left open with caps on. Probably a turbulence issue or it simulates a pressure relief valve issue.

Kind of a dumb mistake to make, but I've seen it myself and it generates a code 11. Closing the service valves fixes it *shrug*
 
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