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tomupnorth
join:2005-01-14
UpperMidwest

tomupnorth to C_Chipperson

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to C_Chipperson

Re: [Plumbing] Frozen Tankless Water Heater Help

said by C_Chipperson:

said by Jack_in_VA:

Wind chill has no effect on equipment.

Wouldn't it? If there is zero wind, then objects can form a small layer of warmer than ambient air near their surface. If the wind is blowing, this can't happen. I'm not saying you're wrong, just something I've wondered about.

It would, though a "-45 wind chill factor" means something different, wind drives cold air into places it otherwise wouldn't get.

robbin
Mod
join:2000-09-21
Leander, TX

robbin to C_Chipperson

Mod

to C_Chipperson
That is not what wind chill is.

C_Chipperson
Monster Rain
Premium Member
join:2009-01-17
00000

C_Chipperson

Premium Member

said by robbin:

That is not what wind chill is.

I know what "wind chill" is, in regards to people and animals. That's not what I was saying at all.

Think about a thin layer of "warm" air just near the surface of a pipe, when there is zero wind. If it is really windy, that layer won't have a chance to form or if the pipe is in a corner or something, more cold air will reach it.

robbin
Mod
join:2000-09-21
Leander, TX

robbin

Mod

Wind chill lowers the temperature below the actual temperature. That is not possible for metal. The actual temp is what is important. Sounds like you are theorizing that the equipment has latent or generated heat which is blown away with wind in cold weather. That's not wind chill.

Jack_in_VA
Premium Member
join:2007-11-26
North, VA

Jack_in_VA to C_Chipperson

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to C_Chipperson
Just effects the human body
Automate
join:2001-06-26
Atlanta, GA

Automate

Member

No, wind chill temperature only applies to the human body but the wind chill "effect" applies to any body or object that is at a higher temperature than the wind such as an outside water heater. The wind causes a greater rate of heat loss due to convection.

With a wind temperature above 32F an object will never freeze regardless of the wind speed. But with a wind temperature less than 32F an object will freeze quicker with higher winds.

The water heater is going to get some amount of heating from the small electric heater and conduction of heat from inside the house through the water pipes. If the temperature is less than 32 and the heat loss from the wind is greater than the heat input from the electric heater and pipes, then it will freeze.

Msradell
Premium Member
join:2008-12-25
Louisville, KY

1 edit

Msradell to C_Chipperson

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to C_Chipperson
Windchill actually affects everything to some degree or another. The windchill numbers that we hear all the time from weather forecasters are based on a formula determines how the wind and temperature combination will affect the human body which is actually the worst case. The combined effect of temperature and wind affects other objects to a much lesser degree.

Here is some information that explains it much better than I can: »en.wikipedia.org/wiki/Wind_chill
Gimmered
Premium Member
join:2005-02-26
Mccook, NE

Gimmered to fire1112

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to fire1112
As far as windchill it doesn't change the temperature, only how fast things cool down to a temperature. If it is 10° outside a car will not get colder than 10° no matter how hard the wind blows.

As to the OP you cannot enclose an outside water heater. They need to be open to vent and also for combustion air to burn.

anon
@cox.net

anon

Anon

I added a Rinnai to an old house and had no choice but to put it outside, mainly because I couldn't fit a side vent anywhere (well I could have built a new chimney through the three storey house....) So don't be too harsh on the builder/installer until you know what went into the decision.
My inlaws in Greenville SC had their's freeze in the recent cold snap; don't know the details and they aren't able to do anything preventative. I did OK in Virginia but might let it drip tonight.
Can't see how heat tape can hurt pex since it's made to carry hot water. Heat tape just isn't all that hot.

pende_tim
Premium Member
join:2004-01-04
Selbyville, DE

pende_tim to fire1112

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to fire1112
Are you going to see any real cold the next few days? If os may want to let a hot water faucet drip ever so slightly to keep things flowing.

It does not take much. just a drip or two second should be enough.

Good luck!
cnyguy
join:2002-01-23
Cicero, NY

cnyguy

Member

said by pende_tim:

Are you going to see any real cold the next few days? If os may want to let a hot water faucet drip ever so slightly to keep things flowing.

It does not take much. just a drip or two second should be enough.

Good luck!

Is the goal to have any water running or hotwater running ?With my Rinnai unless there is a certain level of flow it doesn't even turn on.

pende_tim
Premium Member
join:2004-01-04
Selbyville, DE

pende_tim

Premium Member

Just have a bit of water flowing through the susceptible pipes. It does not have to be hot water. There is enough heat in tap water to keep it from freezing with surprising little flow.

If a low flow will not trigger the heater to fire, all the better; you can save some fuel costs.

DannyZ
Gentoo Fanboy
Premium Member
join:2003-01-29
united state

DannyZ to robbin

Premium Member

to robbin
Wind chill doesn't lower temperatures below the actual temp. Wind chill is an attempt to measure heat loss. A human will lose heat at the same rate approximately at 9 °F with 6mph wind as at -1 °F with zero wind.

Now, an insulated hot water heater probably doesn't experience as much increased heat loss due to wind, but experience it it does. Wind chill affects most everything, living or not.
tomupnorth
join:2005-01-14
UpperMidwest

tomupnorth

Member

said by DannyZ:

Wind chill doesn't lower temperatures below the actual temp. Wind chill is an attempt to measure heat loss. A human will lose heat at the same rate approximately at 9 °F with 6mph wind as at -1 °F with zero wind.

Now, an insulated hot water heater probably doesn't experience as much increased heat loss due to wind, but experience it it does. Wind chill affects most everything, living or not.

Yes, I don't know how anyone could argue that wind has no impact on these types of problems, unless they've never had to choose between parking their car outside (in the wind) vs. inside a non-heated e.g. detached garage (out of the wind). You would always prefer the garage because wind removes heat faster than no wind, period.

I just fixed a broken PVC water pipe yesterday for an outside fixture that faces the North wind. We very rarely get freezing temps for extended periods of time, but if the wind is blowing hard, even a brief period of hard freezing temperatures can result in a pipe bursting.

Pacrat
Old and Cranky
MVM
join:2001-03-10
Cortland, OH

Pacrat to fire1112

MVM

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Wind chill not only affects humans, but all warm-blooded animals. But that's all it affects. Think of blowing on a spoonful of hot soup... yes, the wind does speed up the cooling, but it's not possible to cool the soup beyond the ambient (true) temperature. Inanimate objects are subject to the real temperature, and only the actual temperature of the surrounding area. Wind chill is a "perceived temperature", not a real temperature. A thermometer will still reflect the actual temperature, regardless of whether it is in a dead calm space, or subject to a 30 mph. wind.

XoX
join:2003-08-19
Qc, Canada

1 recommendation

XoX to fire1112

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who in the right mind would install a water heater or any water pipe on the outside wall?

Geez...

Jack_in_VA
Premium Member
join:2007-11-26
North, VA

Jack_in_VA

Premium Member

You know reading the posts and the problems I've wondered the same thing. Very irrational IMO.
fire1112
join:2014-01-03

fire1112

Member

I have wondered the same thing as it doesn't seem rational to place something that could freeze on the outside of a house. However, it seems like a standard practice at least here in SC to install gas tankless water heaters on the exterior of the house. Seems more logical to place it in the garage and vent it to the outside. I'm guessing builders are banking on the typical mild winters and saving the extra costs.

GCVA
@dollartree.com

GCVA

Anon

Got the same problem here in VA. I only have a trickle of hot water. Not sure what to do with a trickle?

pende_tim
Premium Member
join:2004-01-04
Selbyville, DE

pende_tim

Premium Member

If you let it run, the incoming water will thaw the blockage. Once it is running, let the faucet drip.

GCVA
@dollartree.com

GCVA

Anon

I will do that. Thank you!

XoX
join:2003-08-19
Qc, Canada

XoX to fire1112

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unless you heat the garage the same thing might happen...

it's a stupid way to save a few $$ since it cost less in piping... but it's the owner in the end that pay the bills of that.

comeonreally
@optonline.net

comeonreally to pende_tim

Anon

to pende_tim
I can't believe how many people have the drip wrong.

Whole rivers freeze, streams, if anyone thinks a little drip is going to stop the water from freezing... While yes it MAY help the REAL reason is to prevent a broken pipe.

The DRIP allows water to escape, if the pipe freezes and the water has no where to go it will build pressure as more water expands (by freezing) until the water breaks the pipe.

pende_tim
Premium Member
join:2004-01-04
Selbyville, DE

2 edits

pende_tim

Premium Member

Surprisingly enough a little drip works for me.

I agree anything water based will freeze, moving or not, if exposed to a low enough temperature. And yes, water will almost always freeze at 32*F unless it is extremely pure and can be supercooled.

Rivers freeze yes but ponds freeze faster. This is not from the actual movement of the water but from warmer water being stirred up from the bottom of the river as the river flows over the ground temperature river bed.

What we are talking about are pipes that are slightly insulated by the nature of the plastic construction or from being inside a wall. Tap water is typically 50-55* depending on the climate. By letting water flow, the heat from the new water is mixed with the chilling water raising it's temperature. In these cases the heat loss through the walls of the pipe is less than the added heat from the tap water and the water temp stays above 32* in the pipe. It iis all about thermal balance.

And yes I agree that a totally exposed 20' length of 1/2" copper at -20* F will probably freeze even with a drip through it. However flow 1/2 GPM, and it will pass water all day long. The amount you need to flow depends on what you need to balance the heat loss.

While nothing replaces proper installation and thermal protection. drips have worked for me.

Jack_in_VA
Premium Member
join:2007-11-26
North, VA

Jack_in_VA

Premium Member

Same with me. I have some pipes on the inside of an uninsulated cinder block wall that freeze unless dripped.

Msradell
Premium Member
join:2008-12-25
Louisville, KY

Msradell to comeonreally

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to comeonreally
said by comeonreally :

I can't believe how many people have the drip wrong.

Whole rivers freeze, streams, if anyone thinks a little drip is going to stop the water from freezing... While yes it MAY help the REAL reason is to prevent a broken pipe.

The DRIP allows water to escape, if the pipe freezes and the water has no where to go it will build pressure as more water expands (by freezing) until the water breaks the pipe.

The reason a drip in your water system keeps it from freezing is because the water entering the system is usually around 50°- 55° because that's the ground temperature where the pipes are. This is different from the water in a river whose temperature decreases to very close to freezing.

You are right that the drip allows room for the water to escape so the pipe doesn't burst but it also prevents freezing in most cases because of the temperature of the water entering the system.

comeonreally
@optonline.net

comeonreally

Anon

First google result.

»www2.wataugademocrat.com ··· d-013805

"- When the weather is very cold outside, let the cold water drip from the faucet served by exposed pipes. Running water through the pipe -- even at a trickle -- can help prevent pipes from freezing.

- However, water can freeze even with a slow flow. But opening a faucet will provide relief from the excessive pressure that builds between the faucet and the ice blockage when freezing occurs -- which will help prevent a burst pipe.

- Where both hot and cold lines serve a spigot, make sure each one contributes to the drip, since both are subjected to freezing. If the dripping stops, leave the faucet(s) open, since a pipe may have frozen and will still need pressure relief."

Maybe for you guys down south it is to stop the pipe from freezing, here in the NE it is to prevent a burst, if the pipe does not freeze it is just a bonus.

If the pipe stops dripping, DON'T close off the faucet.

Jojoburd
@cox.net

Jojoburd to fire1112

Anon

to fire1112
I also live in South Florida and my tankless water heater must be frozen. I can't even get a drip of water from the hot water faucet. I have put all kinds of insulation, a heating pad and an electric blanket over the entire heater and it has not helped. All the plumbers are not coming out so I don't know what to do. I covered all the brass fittings like I was told the last freeze and still no luck. Am I just wasting more electricity doing all this? I tried the blow dryer and it keeps blowing the circuit breaker. I have gas. Any suggestions?

robbin
Mod
join:2000-09-21
Leander, TX

robbin

Mod

How cold is it there? Daily high and low

DarkLogix
Texan and Proud
Premium Member
join:2008-10-23
Baytown, TX

DarkLogix to robbin

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to robbin

Re: [Plumbing] Re: Frozen Tankless Water Heater Help

said by robbin:

said by cowboyro:

Water pipes outside the house when it can freeze = dumb.
Find a plumber with a brain and move the system inside.

It is very common in southern areas for tankless water heaters to be installed on the exterior of the house. It doesn't take much to let the faucet drip on the few days every few years when the temps get cold enough to potentially cause damage.

WHAT!!!

Guess when I buy a house I'll have to make sure they put it inside, that's IMO total crap to put it outside.

I want all water lines possible ether below the possible freeze line or inside.