These are short circuited problems which are the real serious ones that you should call for tech support.
Cleaning filter on tankless water heater.
You should notice that there are color coded handles underneath your.
Know that a tankless water is not a set it and forget it water heater.
Remove the hose from the cold water side and screw the cap back in place.
Empty the vinegar and place the bucket under the water heater.
Turn the water supply on slowly again to about 1 4 way open.
Close the cold and hot water ball valves on the unit.
Unscrew the water filters and rinse them before putting them back into place.
Add teflon to a threaded fitting and tighten this into the adapter with a pipe wrench and pliers.
I decided to purchase mine through amazon.
Locate the shutoff valves.
You should visit the heater at least once every three months.
The same you d buy at any grocery store.
E407 e421 and e432 issues.
Add an adapter to the inlet side.
Cut through the cold water pipes using a hacksaw and clean the edges with emery cloth.
With the water running out of the hoses turn the valve off on both hoses to stop the flow of water and preventing air from getting into the water heater.
Using the adjustable wrench unscrew the braided stainless steel hose from the cold side connection and remove the filter screen using the needle nose pliers.
Wrap the outlet fitting s threads with teflon tape and tighten it to the outlet side of the filter.
Then place a bucket under the cold side fitting to minimize any spills.
The rinnai is typical.
Reinstall the filter screen.
The solution is the same as for issue e012 that you should clean the air intake filter.
5 steps to cleaning your rinnai tankless water heater filter learn best practices on cleaning your filter from our youtube video learn more.
Navien tankless water heater problems are sometimes hard to comprehend not to mention fix the heater on your own.