# LP water heater problem



## lhort (Nov 10, 2016)

Hi. I am having an issue with my water heater and would like some advice.  Water heater is LP gas, located a few inches away from the basement wall with a vertical rise of 18 inches going straight up to the elbow with a proper pitch. All piping going out of the house meets code, doubled wall pipe, exhaust pipe above roof. I live in New York and if the weather is very cold (0-20 degrees or so) the fumes occasionally can be smelled in the basement. When this happens, the pipes are cold and have condensation, if I open the outside door to provide a draft then the pipe warms up and the fumes go up the exhaust pipe. However, now it seems that this is happening occasionally when the weather is in the lower 30s. My house is not super tight or energy efficient so a draft issue shouldn't really be a problem. There is no blockage in the vent pipes. I have a carbon monoxide monitor and it has never gone off. I am looking for a solution to this problem. Could it possibly have anything to do with my heater being older and maybe doesn't burn as hot as it should to warm the exhaust pipe in cold weather? Could replacing this water heater with a new one be a solution to the problem? Thank you


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## nealtw (Nov 10, 2016)

Do you have a fresh air vent from outside to somewhere near the unit to provide fire air?


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## Snoonyb (Nov 10, 2016)

Warm air has the greater capacity to retain humidity in suspension then cold air. Which can be recognized as dew, fog or condensation.

In your situation, being it loose or tight, air circulation as well as temperature can be a mitigating factor.

If you have sufficient combustion air for the appliance, you might consider a small electric heater to raise the temperature slightly.


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## lhort (Nov 11, 2016)

Hi. Thank you for the responses.

No I don't have a vent near the heater.

Like I had stated, this really wasn't a problem before unless it was bitter cold and nothing in the home has changed. So, why is this happening now?
Could it possibly have anything to do with my heater being older and maybe doesn't burn as hot as it should to warm the exhaust pipe in cold weather? Could replacing this water heater with a new one be a solution to the problem? 
Thank you


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## Snoonyb (Nov 11, 2016)

Water heating appliances have a "life expectancy," and only you know when it was installed, so if your heater is near that, then replace it.

Other then that, we can only offer you assistance in mitigating the conditions you have outlined.


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## lhort (Nov 11, 2016)

Hi. Yes I understand. Just wondering if a simple fix like a new water heater would solve my problem. If so, I would get a new one rather than adding ventilation or switching to electric, etc.


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## lhort (Nov 11, 2016)

Would the "life expectancy" include not heating hot enough so that that the fumes wouldn't go up the flue ?


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## nealtw (Nov 11, 2016)

Is it safe to think that you might have a gas furnace too.
If you do not have air supplied for the fire, where is it getting the air from.
We do know that the humidity level may be to high as you are getting condensation. Then you also need cold to make it condense.
If the furnace or other fans in the house like bathroom or hood fans are pulling air down that vent while the tank is trying to fire it maybe just be over powering the draft.
The hint is opening the door helped.
Let's talk about how hard or easy it will be to add the vent to get needed air in.


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## nealtw (Nov 11, 2016)

Mercaptan is the smell added to gas it is heavier than air. With heat added it will follow the exhaust up the chimney but in colder weather and less wind it could hang around the roof and get sucked back down the chimney as the house needs more air inside.


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## Snoonyb (Nov 11, 2016)

lhort said:


> Would the "life expectancy" include not heating hot enough so that that the fumes wouldn't go up the flue ?



When reaching an appliances useful duration, water heating appliances will typically recover slower, creak, thump and bang, because of the mineral sediments accumulated in the bottom, with little affect upon the venting.

If $500+ is more reasonable than $10 or $20 for a cheap small electric space heater, then go for it.

Only you know the age of the appliance.


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## lhort (Nov 12, 2016)

I just thought that a space heater would be a fire hazard. Not something I would want to leave on unattended at night or when I was working and not at home.


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## Snoonyb (Nov 12, 2016)

You can also set it up on a timer so that it begins circulating warm air, say, 1/2hr before there is a demand for hot water, and it doesn't have to be set to heat the space to a comfort level, just to circulate air warmer than the ambient temperature of the space.


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## KULTULZ (Nov 12, 2016)

lhort said:


> * All piping going out of the house meets code, doubled wall pipe, exhaust pipe above roof. I live in New York and if the weather is very cold (0-20 degrees or so) the fumes occasionally can be smelled in the basement.
> 
> * When this happens, the pipes are cold and have condensation, if I open the outside door to provide a draft then the pipe warms up and the fumes go up the exhaust pipe. However, now it seems that this is happening occasionally when the weather is in the lower 30s.
> 
> ...



All are signs of back-drafting.

As a gas model WH ages and has either hard water introduced and/or does not have sediment(s) drained on a regular basis, it coats the bottom plate and flue causing it to make less actual hot water (and less actual flue temp). It cannot be cleansed or serviced as easily as an electric WH.

Is your gas furnace vented through the same vent?

***************************************
-*Click Here - Why Water Heaters Backdraft -Click Here*-
***************************************


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## lhort (Nov 13, 2016)

Hi. The oil hot air burning furnace has it's own chimney. The water heater's flue pipes are only used for this and run up the outside of the house.


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## KULTULZ (Nov 13, 2016)

Did you click on the blue high lighted text on my post? That should give you an idea of what may be going on.

When a furnace and WH are vented together (which yours aren't), the method of vent connection may cause a back-draft. Can you post a photo of the install?


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## lhort (Nov 14, 2016)

If there was a problem going on like depressurization or not enough air wouldnt installing a powervent heater have the same problem or exasperate the problem for instance when the furnace was on?


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## KULTULZ (Nov 14, 2016)

lhort said:


> If there was a problem going on like depressurization or not enough air wouldnt installing a powervent heater have the same problem or exasperate the problem for instance when the furnace was on?



Yes, it would most likely exasperate the problem..

You would solve that with a Power Vent WH. The combustion air is forced out and also draws fresh outside air.


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## nealtw (Nov 14, 2016)

http://naturalgasefficiency.org/for-residential-customers/combustion_air/


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## KULTULZ (Nov 14, 2016)

nealtw said:


> http://naturalgasefficiency.org/for-residential-customers/combustion_air/



Good info Neal. 

Some info was left out. Below is the website page with more info-

-*EQUALIZ-AIR SYSTEM-*


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## Mastercarpenty (Nov 15, 2016)

The amount of heat going up the flue would be the same new or old as would be the combustion air situation. Usually with new problems you can trace the source to something else 'new' or changed, but that doesn't seem to be the case here. Double-wall pipe will be cooler on the outside than single-wall, and coupled with seasonal changes that might account for the condensation but not the odor. 

Are you positive the entire flue is clear? And how high above the roof is it's exit? Addinf a couple feet of height often solves problems with reversed flow. All gas appliances need a combustion air source and that would also give a bit of air movement to help carry away some humidity too so that's where I'd go after that. Also look down into the W/H flue opening; many have a metal spiral meant to slow the heat rise for better heating and sometimes they rust/collapse/get distorted. That part can be safely removed if it's damaged though you'll lose some efficiency. 

According to Rich Trethewy on This Old House, new gas W/H's are more efficient but the gains are smaller than with electric ones so don't replace it for that reason alone- it won't pay off for you in reduced operating costs. 

Phil


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## slownsteady (Nov 15, 2016)

First be sure that the flue pipe has no leaks or holes and that the seams are sealed with metal tape. That will be the easiest first step to take. If you haven't taken the flue apart to have it cleaned in a while, that would also be advised. If the pipe is not 4 feet (?  - not sure of exact height) above the peak of the roof, - as was mentioned - you could be experiencing a back draft.


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