Navien NCB-240 Combi Boiler - Not prioritizing DHW

Users who are viewing this thread

CM3939

New Member
Messages
7
Reaction score
0
Points
1
Location
Chicago, IL
Hi All -

Having an issue with my NCB 240 combi boiler that I'm hoping someone can help with.

The boiler is not recognizing a call for hot water from our kitchen sink however this only happens when we have the radiant heat in the basement turned on and both sides of the boiler active. The strange thing is if I go to the basement and turn on the hot water in the laundry room sink (which is only a few feet from the boiler) the hot water will work there but then will also work in the kitchen sink afterwards. Also the kitchen issue seems to happen most frequently first thing in the morning after we wake up and haven't been running water in the house for several hours.

I'm fairly handy and would like to address this myself before paying for someone to come out if possible. I'm guessing it's either a pressure issue at the kitchen sink (although the water pressure is perfectly fine) or there is a part in the boiler which is supposed to recognize/prioritize DHW that is going bad.

Any help here would be very much appreciated.

Thanks!

Charlie
 

Fitter30

Well-Known Member
Messages
4,857
Reaction score
944
Points
113
Location
Peace valley missouri
Can't call for dhw and heat at the same time. Is there only one zone for heat? If not how many? What are we they radiate, and or radiators. Is there a zone controller?
 

CM3939

New Member
Messages
7
Reaction score
0
Points
1
Location
Chicago, IL
Can't call for dhw and heat at the same time. Is there only one zone for heat? If not how many? What are we they radiate, and or radiators. Is there a zone controller?

Thanks for the response.

This is a combi-boiler for DHW on one side and heating the water for radiant floor heating on the other.
 

CM3939

New Member
Messages
7
Reaction score
0
Points
1
Location
Chicago, IL
Gpm of your kitchen sink?

Hey John,

Thanks for the response.

That would make sense however it was working perfectly fine for almost a year after I put the faucet in. I took off the nozzle w/ built in sprayer to clean and soak in vinegar. Maybe it was dirty and able to slow down the water flow just enough to where the boiler isn't recognizing it. I can't think of what else it would be unless there is a part I'm not aware of inside the boiler going bad.
 

John Gayewski

In the Trades
Messages
4,726
Reaction score
1,517
Points
113
Location
Iowa
Hey John,

Thanks for the response.

That would make sense however it was working perfectly fine for almost a year after I put the faucet in. I took off the nozzle w/ built in sprayer to clean and soak in vinegar. Maybe it was dirty and able to slow down the water flow just enough to where the boiler isn't recognizing it. I can't think of what else it would be unless there is a part I'm not aware of inside the boiler going bad.
Measure the gpm
 
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