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HVAC Forums => HVAC Help => Topic started by: corrinarusso on January 29, 2022, 09:04:30 AM

Title: ice ice baby ??
Post by: corrinarusso on January 29, 2022, 09:04:30 AM
Hello experts!

Can anyone comment on why this gas pipe thing is creating a huge icicle?
See here: https://postimg.cc/phV3xhvH

All I know is that it is attached to the furnace somehow.

Is something broken in the furnace? or does this seem normal.
I don't know if you can see it in the picture, but the other white pipe at the top has lots of snow around it as well.

Any advice would be hugely appreciated!
:-)

Corrina

Title: Re: ice ice baby ??
Post by: Sergroum on January 29, 2022, 10:47:26 AM
It's not a gas pipe, it's a vent pipe. It's ment to suck outside air and bring it to your furnace for combustion purposes. That's not the air you breathe, it's the air that the flame is using for fuel.

When it's cold outside and warm inside, the air being sucked in condenses and forms moisture. It's slowly dripping out of that elbow and turns to ice.

Few things to consider.

Sometimes, that moisture drips inside your furnace if the venting is done without this possibility in mind. Ask if there is any evidence of that next time you are doing some kind of furnace maintenance.

Sometimes if you have a grill on the outside pipe, Ice coats that grill and blocks that pipe entirely. Your furnace will stop working until you clear the obstruction and reset your system.
Title: Re: ice ice baby ??
Post by: corrinarusso on January 29, 2022, 12:38:43 PM
Hi Sergroum!
I appreciate the reply - it makes sense to me.

Is there any action I need to take on the furnace or anything else? (other than kicking away the icicle every few days, lol)
The pipes seem clear to me, nothing obstructing them.

Corrina
Title: Re: ice ice baby ??
Post by: Sergroum on January 29, 2022, 02:07:59 PM
For the outside. Just be mindful of it, yup.

For the possibility of the water deippage inside the furnace, it depends on install and the model. Not a fact it's even a factor in your case. In which case, do not worry.  If the water does drip, next time a tech is doing maintenance on the furnace, they are going to go,"Hey. What's with the water marks? This can kill your gas valve." And if that happens, there might be some alterations to pipe suggested. Again, not a fact this is even an issue for you. Just something we all periodically see in people's houses.
Title: Re: ice ice baby ??
Post by: corrinarusso on January 29, 2022, 02:09:54 PM
Great - thanks again for the feedback.

Very appreciated.
Title: Re: ice ice baby ??
Post by: NoDIY on January 29, 2022, 03:06:34 PM
It would appear the intake and exhaust are reversed..

The upper pipe should be exhausting combustion products but it looks like it's sucking in snow and frost as you can see there is a partial blockage in it.

The lower pipe should be the intake for fresh air into the furnace.. it's very rare to see that kind of ice build up under an intake..

It would appear your lower pipe with 90 pointing down is actually exhaust. The hot moist exhaust is going up and into your intake and freezing causing frost inside the elbow.

If this is the case it should be corrected. Perhaps a post a picture or video of it running..
Title: Re: ice ice baby ??
Post by: NoDIY on January 29, 2022, 03:08:19 PM
Also that silver hood looks like a dryer exhaust. It needs to be at least 3ft away from an appliance intake.
Title: Re: ice ice baby ??
Post by: Sergroum on January 29, 2022, 03:59:19 PM
No way.    OP, when your unit is working, which pipe is the steam coming out of?
Title: Re: ice ice baby ??
Post by: Porcupinepuffer on January 31, 2022, 05:07:18 AM
Yeah the pipes are accidentally reversed from the installer... Wouldn't be the first time this has happened.  ;D