Navien CR240 combi seems to be stuck in heating mode, not switching to DHW

Users who are viewing this thread

jeremyb73

New Member
Messages
1
Reaction score
0
Points
0
Location
Colorado
I've got a Navien Combi 240a which is giving inconsistent and low domestic hot water out.

I do not have the remote but the LED on the unit shows supply temps which oscillate from 180 down to 150. I assume this is not the DHW output because the DHW output pipe is only warm to the touch.

The mixing loop for the hydronic heat, however, is scalding.

My understanding is that there is a valve inside which is supposed to switch the primary heat exchanger loop to the DHW heat exchanger when DHW is called for.

I am not calling for heat at all because it's august. My Taco controller is not showing either thermostat calling for heat and my heating loop pumps and valves are not running.

Last winter, on particularly cold days I had issues with a "low pressure on heating side" error, which hasn't happend in this summer.

Can anyone weigh in on these questions -

Is the three way valve sticking?

Did my installer jack up the install somehow when wiring the heating controller? The DHW was flawless before having the heating loop wired, but it has seemed to work well this summer.

Is there a setting to disable the heating mode entirely until I get this figured out?

Is anyone in Denver area an expert or know an expert on Naviens?

Thanks!
 
Top
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) terrylove.com can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks