20 Most Recent Rheem Tankless Water Heater Manifold Control Box Questions & Answers

most likely a flame sensor problem.remove fl sensor , clean with steel wool or fine emery cloth,replace and it should solve yor problem

Rheem Tech support recommends using default of 20 for both is old settings can not be retrieved from old PCB. Had the same issue and factory settings work well. Also in Lafayette

Here is the manual. See instructions on page 2.

Here is the link to the service manual for your tankless water heater:

http://globalimageserver.com/fetchDocument.aspx?id=14564cf7-cd7b-4814-9e1f-4fea34c7b30c

See page 35 for specifics regarding dip switch settings. If you have problems with the link, post again and I will publish it on my company website for you to review.

Richard Johnson
EMSHVAC, Inc
[email protected]

The C4 is a sequence number, there should be a series of numbers that flash after the C4, what is that number?

If you want to see the entire error code list for the Rheem tankless hot water heaters, it can be found at this link:

http://www.emshvac.com/Rheem_Tankless.htm

Most likely problem is the flow sensor on the inlet and/or outlet pipe. It measures flow to ensure minimum flow before the unit lights. Sometimes they stick or go bad resulting in the control thinking that there is no water flow. Depending on where you purchased it, it may still be under warranty. Call your installing contractor.

check wiring

I can find nothing on this error message. There are troubleshooting tips, but you may need to contact Rheem Support direct. https://www.google.com/search?q=rheem+propane+pool+heater+troubleshooting ..

check filter if ok check pressure switch

Find your manual and see if it will give you the information https://www.masterspas.com/hot-tub-owners-manuals

Current time of day; system message, not an error

Check for debris near igniter. You may have gotten it wet. I don't know the model but you will either have a snap sound every few seconds or it will have a heater element that glows bright red when starting .