Lochinvar NKC 150 Noble combi boiler emitting water...

BostonKGK

Hello,
Just had the new Lochinvar Noble NKC 150 combi unit installed last week in my 110 year old house. Hot water and heat come out good. But whenever I used the washing machine, an open pipe under the unit would emit water concurrantly with the water hammering in the pipe system. I had loud bangs in the pipe system whee using the washing machine before, but the old Rinnai combi never emit water with water hammering. Is this concerning with the new unit? Also, "Outdr Sensor Missing" is on the front window. Is that normal? Thank you for your thoughts.

Alan (California Radiant) Forbes

Call the installer back. What you're experiencing is not normal.

The outdoor sensor should be installed and your boiler programmed accordingly. And don't let him charge you any extra!

hot_rod

Might need a domestic water expansion tank

BostonKGK

Video showed the water emitting with hammering: https://www.youtube.com/watch?v=A-xV7QKA7_U

Alan (California Radiant) Forbes

That’s your pressure relief valve discharging water. It should have been piped to the outside of the house. 

Since it’s a new installation, I’d say you’ve got air stuck in the boiler’s heat exchanger. 

See if there’s an air vent at the top of the boiler with a small, screw-on cap. I would loosen the cap to see if any air comes out. If not, your boiler needs a proper purging. 

Careful: The water could be very HOT!

GroundUp

Alan (California Radiant) Forbes said:

That’s your pressure relief valve discharging water. It should have been piped to the outside of the house. 

Since it’s a new installation, I’d say you’ve got air stuck in the boiler’s heat exchanger. 

See if there’s an air vent at the top of the boiler with a small, screw-on cap. I would loosen the cap to see if any air comes out. If not, your boiler needs a proper purging. 

Careful: The water could be very HOT!

That is the domestic water relief and has nothing to do with the heating side or exchanger. Also, who pipes a relief to the outdoors? This isn't steam.

GroundUp

The outdoor sensor came with the boiler in a little white box. It doesn't need to be installed, but it will maximize efficiency if it is. The installer skipping that as well as a downpipe on the relief valve indicates they may have skipped some other steps as well, such as an expansion tank. Can you show us all the piping and boiler together? Is this city water or is it on a well?

Alan (California Radiant) Forbes

@GroundUp said:

Also, who pipes a relief to the outdoors?

I guess I do plus a few others under the jurisdiction of the Uniform Plumbing Code.

BostonKGK

https://www.youtube.com/watch?v=IKVq7gRZLms

pedmec

you are not required to bring the relief valve drain outdoors in cold weather towns. it can create an unsafe walking condition if it freezes. not required in mass code

GroundUp

Alan (California Radiant) Forbes said:

@GroundUp said:

Also, who pipes a relief to the outdoors?

I guess I do plus a few others under the jurisdiction of the Uniform Plumbing Code.

Get yourself a new code book. UPC 608.5 allows relief piping run to a drain with an air gap, and every state colder than California does it that way. A lot of work for an inferior solution, IMO

GroundUp

City water or well water? I don't see an expansion tank on the domestic water side. Also, the circulator is mounted wrong.

Alan (California Radiant) Forbes

@GroundUp I just wanted to answer your question, "....who pipes a relief to the outdoors?" Kudos to you to point out alternatives.

Contrary to your opinion, I believe discharging outside the building is a better solution - in warm climates. It doesn't make a mess on the floor, no property damage and if piped to a drain, you may never notice it leaking. A leak outside the building is more noticeable and it does no damage. Most contractors here pipe it outside unless there's no way to get it out.

@BostonKGK When does that sound and leakage happen? When you're running a faucet?

BostonKGK

City water is used.

The water only emitted when hammer happened. And hammer happened only when the washing machine is in use. 

So for now, I just placed a basin underneath to catch the water (about 2 oz) when the washer is running. Is this a good solution?

Will the circulator mounting mistake cause problems?

GroundUp

@Alan (California Radiant) Forbes well, you DID say it "should have been piped to the outside", which is 100% false. You're entitled to your opinion, but nobody I've ever met would notice water trickling outside where they never are before they'd notice water trickling inside their home where they spend 40% of their life. Plus, the OP's name containing Boston might be a good indication that your suggestion was terrible and dangerous.

GroundUp

@BostonKGK the circulator mounting position will not affect the issue you're seeing here, but it should still be corrected. If you're on city water, there needs to be an expansion tank on your domestic water side. Maybe there is, but I didn't see it in your video. Can you verify? This behavior is typical of washing machines and many washer boxes use valves with integrated hammer arrestors for this reason. If you don't have an expansion tank, get one added ASAP. If you already do have one, perhaps a hammer arrestor on your washing machine circuit would be a good option. Regardless of what happens, that circulator should be rotated 90 degrees and the relief valve should be replaced as well as piped down toward the floor.

BostonKGK

BostonKGK

Is the gray tank a domestic water expansion tank? Thanks.

GroundUp

I can't see how it's connected to the system, so I don't know for sure, but it appears to be a hydronic tank. There needs to be two separate tanks- one for the hydronic and one for the domestic.