Warm water mornings on cold line for 30 secs....

[Nikolaos]

We have been living in a home built in 2011 (in Canada) and have just started experiencing the following:

In the morning the cold water in our kitchen and powder room sinks runs warm for about 30 seconds and then turns cold and is fine. Days have been really cold (-30 celsius with wind chill) and the heating system runs a fair bit in the morning and so I suspected the cold line may be too close to a heating vent in the basement.

I found 2 things that I thought might be a problem:

1) The cold water line crosses over the main heating line from our furnace / unfinished basement (the other 1/2 of the basement is finished). So I put some insulation to create some sort of separation but didn't help.

2) The hot and cold lines that lead to/from the tankless water system are close to each other so again I tried to ensure there was a barrier of insulation at points of contact. Didn't help.

We have PEX 3/4" piping that leads to 1/2" segments throughout the house.

Is there a special type of foam or tubing that would wrap around the 3/4" piping to keep it from being heated? Should I be looking elsewhere like single lever sink handles or washing machine valves?

Any advice / help is sincerely appreciated as I am stumped!!!!!

 

[WJcandee]

Are you sure you don't have a hot water recirculation system like the Grunfos Comfort System installed, which, on cold days, runs a small amount of the hot over to the cold side at the far end of the water line, so that when you open the hot tap you get warm water almost immediately, and hot water shortly thereafter? We have it and it rocks, but when it's really cold outside, you get a little warm water from the cold for a few seconds, which isn't objectionable to us.

You might also have a small amount of crossover from a single-handle shower faucet.

 

[Sponsor]

 

[Nikolaos]

Are you sure you don't have a hot water recirculation system like the Grunfos Comfort System installed, which, on cold days, runs a small amount of the hot over to the cold side at the far end of the water line, so that when you open the hot tap you get warm water almost immediately, and hot water shortly thereafter? We have it and it rocks, but when it's really cold outside, you get a little warm water from the cold for a few seconds, which isn't objectionable to us.

You might also have a small amount of crossover from a single-handle shower faucet.

I never knew about the Grunfos Comfort System. We definitely don't have that system in place. Can it be installed with a tankless hot water system? Can it be installed for showers as well as sinks (i.e. it appears that another line needs to be run to each point where instant hot water is needed - is that true?)

The warm water lasts for quite some time as I mentioned (about 30 seconds) so it doesn't appear to be anything like Grunfos cutover anyways. It's very similar to how we have to wait for our hot water to warm up with our tankless system but in reverse. That is why it is so annoying... i.e. in the morning we want to drink cold water and have to wait for it to get cold (despite it being -30 outside) then if you need hot water you have to wait for it to get hot (the latter being normal of course). Really annoying

We have 4 delta single handle shower handles and 6 delta single handle sink handles over a 3 floor home. How do you go about ruling out which one might be problematic? What would be problematic in the handle? What about the washing machine washer inlet valve?

Thoughts???? Appreciate it.

 

[Nikolaos]

Was just doing some research and came across:
http://www.aehodge.com/warm-water-from-cold-taps-fugitive-household-goes-plumbing-crazy/

Turns out we do have another single faucet handle in the laundry room and its a Moen. Also the kitchen sink has a single handle Grohe.

Unfortunately the builders didn't place shut off valves under any of the sinks so shutting them off isn't going to help determine where the issues lies.

 

[WorthFlorida]

The site you found is right and it maybe a problem in your home since it only recently started. I remember back in the 1960's my dad found that it was the water valve in the old Westinghouse washer that was the problem. So it is easy enough to turn off the water at the washer. Pull the hoses off and blow into the hot water hose (or cold) and see it any air comes out of the other hose. It shouldn't, if it does you found the problem. Also do your water test. For it to be from a faucet while the faucet is turned off I think it would a slim chance. With no shut offs at the faucets do you have a manifold that distributes water to each water fixture? There would be a shut off at the manifold.

Here is trick that may work. Turn off the hot water supply so there is no chance of hot water can flow to any faucet. Go to all faucets and turn on the hot side only. No water other than water left in the line should come out. If any one with the hot side open and cold water flows, you got it. I think all faucets today have build in check valves in the valving to prevent just this problem. If your running warm water (both hot and cold are open) and a sudden drop in pressure on one side, water should be prevented from cross flowing. I could be wrong so maybe someone with experience may know. Two handle faucets probably would not.

If water flows from all of them there is one faucet is feeding water to the from the cold to the hot, or all faucets do this anyway. If water does stop flowing out of the hot water side the water will take to lower pressure route and may stop crossing over.

I hope this doesn't sound to confusing.

 

[hj]

quote; . I think all faucets today have build in check valves in the valving to prevent just this problem. I

Very few tub/shower faucets, and almost NO sink faucets, have check valves in them. Delta faucets DO NOT cause crossover, so it is what is happening it would have to be the Moen valve and you can test that by turning off the hot water to the faucet.

 

[Nikolaos]

quote; . I think all faucets today have build in check valves in the valving to prevent just this problem. I

Very few tub/shower faucets, and almost NO sink faucets, have check valves in them. Delta faucets DO NOT cause crossover, so it is what is happening it would have to be the Moen valve and you can test that by turning off the hot water to the faucet.

Okay. So finally got around to testing things.

1 of 4 Delta single lever showers exhibited a fair amount of water flow when the hot water was shut off. This unit only has a shower component (i.e. no faucet spout at the base of the shower). The other 3 also had a small steady stream of water flow. Definitely 1 needs its cartridge to be replaced but perhaps all 4. Thoughts???

Of the single lever delta sink faucets... 2 had a drip every 1 second... 1 had a drip every 2 seconds and 1 had a drip every 3 seconds... the last 2 didn't drip at all? Are these within a normal range or should I be looking to change cartridges in these as well? Thoughts???

The Groehe faucet was fine.

Appreciate the advice. Thanks.

 

[Jadnashua]

MOdern shower valves typically have a pressure balance valve in them (performs the anti-scald function), and when working right, if you've shut off one supply, you should not get much of any water out of the valve from the other supply. On the one, either it's really old, or the pressure balance function is jammed. I do not know on Delta if that is in the cartridge, or is a separate piece. YOu should be able to tell with the model number and the parts breakdown, though. The designs vary, I think a little flow may be normal, but on some, it does literally shut off when you only have one supply turned on.

Vanity and kitchen sink single handle faucets do not have that function, so if all the way to one side, there should not be any flow when you've shut off the supply.

 

[Nikolaos]

MOdern shower valves typically have a pressure balance valve in them (performs the anti-scald function), and when working right, if you've shut off one supply, you should not get much of any water out of the valve from the other supply. On the one, either it's really old, or the pressure balance function is jammed. I do not know on Delta if that is in the cartridge, or is a separate piece. YOu should be able to tell with the model number and the parts breakdown, though. The designs vary, I think a little flow may be normal, but on some, it does literally shut off when you only have one supply turned on.

Vanity and kitchen sink single handle faucets do not have that function, so if all the way to one side, there should not be any flow when you've shut off the supply.

It is a relatively new home (built in 2011) and all 4 showers were installed at the same time. The one with a lot of water flowing when shut off is the one in the master bathroom which is used 2X more than the others and makes some sense. Good to hear that some flow from the showers is fine. I will definitely try to get the 1 fixed.

The kitchen sink is a Groehe and does completely stop flowing any water. As I said 2 vanities completely stop. There are 2 others that drip every 1-3 seconds. Do you recommend that the 1-3 SECONDS per DRIP warrants fixing any of the vanity sinks?

 

[Nikolaos]

Wow. Delta provides a lifetime warranty to the 1st home buyer. They will be sending a cartridge for the shower.

I just wanted to get feedback on 2 points:

1) The shower is upstairs on the 2nd floor yet the kitchen sink and powder room vanity that run warm at start in the morning are on the 1st floor. I though warm water rises and if so does this make sense and if so how?

2) I was wondering about something else too. We have 3/4" PEX piping that runs just a mere 1 inch over the main heating duct emanating from the furnace. The duct radiates a lot of heat as it is 2 parallel ducts. Due to the extreme cold outside our heating system kicks into high gear every morning. Could heat be transferring to the water line such that the cold water becomes warm? Also is there some sort of sleeve that people place over the PEX line (it would have to be something that has a slit that could be put over the length of the line)? Does such a thing exist?

Thanks.

 

[Reach4]

2) Yes, yes, and yes. Pipe insulation like that is readily available. It is not specific to PEX. Note that insulation slows heat transfer, but given enough time, the heat will come through. It just takes longer.

 

[Jadnashua]

The best stuff will have an R-rating of about R4 (maybe better) and will be a closed-cell foam rather than open-cell. You may have a better chance of finding good stuff at a plumbing supply house verses the big box stores. While you're at it, it will help both the cold AND the hot lines to insulate them, wherever you can gain access except possibly in an outside wall. Insulation there might keep the heat from the house from preventing it from freezing. There is no such thing as what we call cold...it is an absence of heat, and heat always wants to spread itself out and make everything even...insulation slows that process down.