Navien NPE 240A NG, Not getting as hot

[mrbatbhs]

My 5 year old Navien NPE 240A NG is not getting as hot today as yesterday. I called tech. support and he walked me through checking some of the numbers and thinks that it is a bad check valve.
And wouldn't you know it, parts went out of the 5 year warranty 2 months ago. I am a bit upset as we paid a lot of money for this unit to be installed.

That being said, how hard is it to replace a check valve?

Thanks,

Will

 

[Breplum]

Super easy.
There is a stainless steel U clip that has a bent over edge.
Once water and power is off, and depressurized (remove both big black plastic drain fittings under the unit to help get most of the water out.
Then pop up the U clip and pull on the black tab. Sometimes a pair of pliers help. Just friction of o-rings to resist.
Pop the new check valve in and you are good to go.
You can get by now before the new one arrives by pulling the check valve and poking the internal moving piece to free it up, bc it is just hanging up from age.

The check valve is on the right side just a few inched off the bottom of the case.

 

[Sponsor]

 

[mrbatbhs]

I drained the tank and cleaned the inlet filter, but did not see the check valve. Also, I have a picture inside of the unit and wanted to see if anyone knew if this is an issue?

 

[mrbatbhs]

Thank you.

I have ordered a new check valve, but in the meantime, I took the old one out and see that it was stuck open. It looks like the o-ring is enlarged and loose on the valve. I cleaned it up and put it back together and it is working for now.

 

[Bannerman]

With the check valve stuck open, cold water can flow to the hot outlet which is why your hot water was not hot.

Since you were able to get the old one working and as it is already reinstalled, keep using it for as long as possible but once it again causes a problem, you'll have a new one ready for replacement. As they are not usually expensive, suggest always keeping a spare available.

 

[Breplum]

For the record, the check valves are definitely failure prone on Navien NPE A series.
I have replaced a ton of them from this exact complaint of temperature drift.
Usually it happens well before the 6 yr. parts warranty expiration.