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Marc, Plumber
Category: Plumbing
Satisfied Customers: 1126
Experience:  Plumbing heating & home maintenance contractor
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Rinnai V1200 water heater with Smartstart and a MC 910

Customer Question

Rinnai V1200 water heater with Smartstart and a MC 910 controller. Water temp increases and then heater turns off. Error Code 10 on controller. Appears that temp rises and overtemp switch cuts unit out. If power is turned off and on, unit operate but then cuts out. Suspect thermistor - is this correct.
Submitted: 1 year ago.
Category: Plumbing
Customer: replied 1 year ago.
Controller MC 91Q 2A
Expert:  Jed Noble replied 1 year ago.

Hello, my name is***** am a plumbing contractor.

I looked up an error code 10 and this is the result.

Air intake or flue blocked.

Have you inspected the exhaust pipe, this time of the year it could ice up.

Let me know what you find? I have worked on rinnai as well as taken a certification course on rinnai hot water heaters and am happy to help troubleshoot.

Expert:  Jed Noble replied 1 year ago.

This is the manual that I found online.

Customer: replied 1 year ago.
Unit is an outside unit with no flue. Have checked air intake and outlet with no obstructions. Have noticed that heater works for 5 minutes every time it is reset and then cuts out with a flashing 10 on the controller
Customer: replied 1 year ago.
I already have that manual but thanks all the same. It does not address my current problem
Expert:  Jed Noble replied 1 year ago.

This is a troubleshooting guide provided to professionals, It looks like this guide says to look the dip switch settings and heat exchanger. If the unit is new I would look at the dip switches if the unit is older I would look through the combustion port to see if the flame draws well towards the exhaust. Please don't try anything on this guide without checking with me or Rinnai.

Customer: replied 1 year ago.
Thanks Jed
As per Temperature Dip Switch Settings Chart settings are
SW1 - All (except 3) OFF, 3 ON
SW2 - All (except 1) OFF, 1 ON - Natural Gas
I Notice that SW1-1 and SW2-2,3&4 are "model type" settings - but I do not have the "model type chart" to check they are correctly set.
Expert:  Jed Noble replied 1 year ago.

I will contact Rinnai this morning to find out the correct switch settings. Is this an AU model?

I will post back in the today.

Customer: replied 1 year ago.
AU model
Expert:  Jed Noble replied 1 year ago.

I was not able to get your dip switch settings they Rinnai USA could not help and Rinnai AU wants me to be an Au tech, I'm sorry.

If you look on the back of the cover for an instruction sheet probably in a plastic bag, in the US, the dip switch setting are there. Let me know if you find them.

Customer: replied 1 year ago.
Only a schematic wiring diagram. Looks like you are not able to help and I may need to re-address my issue to an AU tech (I thought that you were in AUS).